Abstract: Background: Patients with follicular lymphoma (FL) have a heterogenous prognosis. Recently a simple score, the PRIMA-PI, was developed based on the PRIMA clinical trial (Bachy et al Blood. 2018). With only two factors (beta-2-microglobulin level & gt; 3 mg/L and bone marrow involvement), this index was at least as discriminatory as FLIPI on the training and validation cohorts. The validity of the PRIMA-PI was confirmed on Czech and German FL cohorts and a patient group from the Nordic Lymphoma Group. However, further validation is needed to confirm the use of PRIMA-PI in place of FLIPI for prognostic assessment. Indeed, in the era of new chemo-free treatments, it seems important to challenge the potency of traditional prognostic factors and scores. Recently, rituximab combined with lenalidomide (R2) was compared to conventional immunochemotherapy (R-chemo) in the phase III RELEVANCE trial. The aim of our study was to validate PRIMA-PI in the RELEVANCE trial cohort and compare its performance with FLIPI (Solal-Celigny et al. Blood. 2004) and FLIPI2 (Federico et al. JCO. 2009). A secondary objective was to evaluate potential differences in terms of prognostic bio-clinical parameters between the R2 and R-chemo arms. Methods: All patients with available data for FLIPI, FLIPI2, and PRIMA-PI from the intention to treat population of the RELEVANCE study were included in the analysis. PFS according to each prognostic score were assessed in the total population and by treatment arms. Data were not mature enough to compare OS distributions. Performance metrics (log-rank p value and Net Reclassification Improvement [NRI]) were calculated for each group to assess concordance and discriminating ability of each score. Results: Median follow-up time for the study was 38 months. Overall, 846 RELEVANCE patients were included in the analysis. Data were available for 845 patients for FLIPI score assessment, 832 for FLIPI2 and 807 for PRIMA-PI. Group repartition according to the FLIPI and the FLIPI2 were largely imbalanced compared with PRIMA-PI. FLIPI classified very few patients in the low risk group (15% LR) while 49% of the patients were at high risk (HR), and 36% were at intermediate risk (IR). Similarly, FLIPI2 risk categories were as follow: 8% LR, 50% IR, and 42% HR. On the contrary, PRIMA-PI divided the study population into three equal groups (33%, 33% and 34%). In the total population, FLIPI and PRIMA-PI were predictive of PFS (p=0.029 and p=0.004, respectively); FLIPI2 showed poor performance (p=0.094). PFS curves based on each score are shown in Figure 1. NRI index indicated that the PRIMA-PI yielded analogous segregation for PFS with FLIPI (NRI 0.16; 95% CI: -0.008, 0.318; Table 1). In the R-chemo arm, both FLIPI and PRIMA-PI could isolate different prognostic groups for PFS, whereas FLIPI2 could not. Conversely, none of the indices were able to significantly discriminate outcomes for patients treated with R2. Interestingly, analysis showed that some usual prognostic factors, especially those likely to reflect tumor burden such as beta-2 microglobulin and LDH, were not predictive for PFS in the R2 arm. In contrast, low albumin ( & lt;40 g/L) and low hemoglobin ( & lt;120 g/L) levels were significantly associated with worse PFS in the R2 arm (p=0.001, and p=0.023), but not in the R-chemo arm. Conclusion: For patients with FL treated upfront with immunochemotherapy, the PRIMA-PI is a valid scoring system that allows to segregate patients as efficiently as the FLIPI while using only two factors. These results confirm that the PRIMA-PI could substitute for the FLIPI for patients treated with upfront R-chemo. Athough our data have to be interpreted in light of the short median follow-up time, they also suggest that other clinical/biological parameters might be considered and new prognostic indexes established for patients treated with R2. Considering possible mechanisms of action of lenalidomide, prognostic factors related to the underlying patient's immunological status might be more predictive. Disclosures Fowler: Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis Pharmaceuticals Corporation: Consultancy; ABBVIE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding. Bachy:Roche: Consultancy; Janssen Cilag: Honoraria; Gilead Science: Honoraria; Amgen: Honoraria; Roche: Honoraria; Janssen Cilag: Other: Travel, accomodation, Expense. Feugier:abbvie: Honoraria, Research Funding, Speakers Bureau; roche: Honoraria, Research Funding, Speakers Bureau; janssen: Honoraria, Research Funding, Speakers Bureau; gilead: Honoraria, Research Funding, Speakers Bureau. Tilly:roche: Membership on an entity's Board of Directors or advisory committees; servier: Honoraria; merck: Honoraria; Gilead: Honoraria; Janssen: Honoraria; BMS: Honoraria; Karyopharm: Consultancy; Astra-Zeneca: Consultancy; Roche: Consultancy; Celgene: Consultancy, Research Funding. Palomba:Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Noble Insights: Consultancy; Evelo: Other: Immediate family member, Equity Ownership; MSK (IP for Juno and Seres): Other: Immediate Family Member, Patents & Royalties - describe: intellectual property rights ; Hemedicus: Other: Immediate Family Member, Speakers Bureau ; Merck & Co Inc.: Other: Immediate Family Member, Consultancy (includes expert testimony); Seres Therapeutics: Other: Immediate Family Member, Equity Ownership and Membership on an entity's Board of Directors or advisory committees; STRAXIMM: Other: Immediate Family Member, Membership on an entity's Board of Directors or advisory committees; Kite Pharmaceuticals: Other: Immediate Family Member, Membership on an entity's Board of Directors or advisory committees. Libby:Akcea: Consultancy; Alnylam: Consultancy; Abbvie: Consultancy; Pharmacyclics and Janssen: Consultancy. Casasnovas:Merck Sharp and Dohme: Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses. Flinn:TG Therapeutics, Trillum Therapeutics, Abbvie, ArQule, BeiGene, Curis, FORMA Therapeutics, Forty Seven, Merck, Pfizer, Takeda, Teva, Verastem, Gilead Sciences, Astra Zeneca (AZ), Juno Therapeutics, UnumTherapeutics, MorphoSys, AG: Research Funding; F. Hoffmann-La Roche Ltd: Research Funding; TG Therapeutics, Trillum Therapeutics, Abbvie, ArQule, BeiGene, Curis, FORMA Therapeutics, Forty Seven, Merck, Pfizer, Takeda, Teva, Verastem, Gilead Sciences, Astra Zeneca (AZ), Juno Therapeutics, UnumTherapeutics, MorphoSys, AG: Research Funding; AbbVie, Seattle Genetics, TG Therapeutics, Verastem: Consultancy; Acerta Pharma, Agios, Calithera Biosciences, Celgene, Constellation Pharmaceuticals, Genentech, Gilead Sciences, Incyte, Infinity Pharmaceuticals, Janssen, Karyopharm Therapeutics, Kite Pharma, Novartis, Pharmacyclics, Portola Pharmaceuticals: Research Funding. Haioun:Novartis: Honoraria; Janssen: Honoraria; F. Hoffmann-La Roche Ltd: Honoraria; Servier: Honoraria; Takeda: Honoraria; Miltenyi: Honoraria; Gilead: Honoraria; Celgene: Honoraria; Amgen: Honoraria. Bartlett:Pharmacyclics: Research Funding; Pfizer: Research Funding; Affimed: Research Funding; Celgene: Research Funding; Millenium: Research Funding; Merck: Research Funding; Seattle Genetics: Research Funding; Forty Seven: Research Funding; Bristol-Myers Squibb: Research Funding; ADC Therapeutics: Consultancy, Research Funding; Genenetech: Research Funding; Gilead: Research Funding; Immune Design: Research Funding; Janssen: Research Funding. Bouabdallah:Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Brice:BMS: Honoraria; Millennium Takeda: Research Funding; Takeda France: Consultancy, Honoraria. Ribrag:Nanostring: Membership on an entity's Board of Directors or advisory committees; Servier: Consultancy, Membership on an entity's Board of Directors or advisory committees; Epizyme: Consultancy, Research Funding; ArgenX: Research Funding; Roche: Other: Travel, accommodations, and expenses ; BMS: Membership on an entity's Board of Directors or advisory committees, Other: Travel, accommodations, and expenses ; MSD: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Infinity: Membership on an entity's Board of Directors or advisory committees; AZ: Membership on an entity's Board of Directors or advisory committees. Le Gouill:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support; Roche-Genentech: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support. Martín:Teva: Research Funding; Gilead: Consultancy, Honoraria; Kiowa Kirin: Consultancy; Roche: Consultancy, Honoraria, Other: Travel Expenses; iQone: Consultancy; Servier: Honoraria, Other: Travel Expenses; Janssen: Honoraria, Other: Travel Expenses, Research Funding; Celgene: Consultancy, Honoraria, Other: Travel Expenses, Research Funding. Lopez-Guillermo:Roche: Consultancy, Research Funding; Gilead: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Janssen: Research Funding. Larouche:Bayer; Gilead Sciences; Merck; Roche: Research Funding. Ando:Eisai: Research Funding. Maria:Janssen Cilag: Consultancy, Other: Travel support; Gilead Sciences: Other: Travel support, Research Funding; Abbvie: Consultancy, Other: Travel support; Celgene: Consultancy; Roche: Consultancy, Other: Travel support. André:Takeda: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers-Squibb: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees, Other: Travel grants; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Roche: Other: Travel grants, Research Funding; Amgen: Other: Travel grants, Research Funding; Johnson & Johnson: Research Funding; Takeda Millenium: Research Funding; Chugai: Research Funding; Celgene: Other: Travel grants, Research Funding. Sehn:Merck: Consultancy, Honoraria; Acerta: Consultancy, Honoraria; TEVA Pharmaceuticals Industries: Consultancy, Honoraria; F. Hoffmann-La Roche/Genentech: Consultancy, Honoraria, Research Funding; TEVA Pharmaceuticals Industries: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Astra Zeneca: Consultancy, Honoraria; Lundbeck: Consultancy, Honoraria; Kite Pharma: Consultancy, Honoraria; Kite Pharma: Consultancy, Honoraria; Astra Zeneca: Consultancy, Honoraria; Acerta: Consultancy, Honoraria; Morphosys: Consultancy, Honoraria; Janssen-Ortho: Honoraria; Janssen-Ortho: Honoraria; F. Hoffmann-La Roche/Genentech: Consultancy, Honoraria, Research Funding; Merck: Consultancy, Honoraria; TG Therapeutics: Consultancy, Honoraria; TG Therapeutics: Consultancy, Honoraria; Lundbeck: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Morphosys: Consultancy, Honoraria. Tobinai:Daiichi Sankyo: Consultancy, Honoraria; Eisai: Honoraria, Research Funding; Verastem: Honoraria; Mundi Pharma: Consultancy, Honoraria, Research Funding; Zenyaku Kogyo: Consultancy, Honoraria; Yakult: Honoraria; Janssen Pharmaceutical: Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; HUYA Bioscience: Consultancy, Honoraria; Ono Pharmaceutical: Consultancy, Honoraria, Research Funding; Chugai Pharmaceutical: Honoraria, Research Funding; AbbVie: Research Funding; Solasia: Honoraria; Meiji Seika: Honoraria; Kyowa Kirin: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria; Takeda Pharmaceutical: Consultancy, Honoraria, Research Funding. Cartron:Roche, Celgene: Consultancy; Sanofi, Gilead, Janssen, Roche, Celgene: Honoraria. Delarue:Celgene Corporation: Employment, Equity Ownership. Czuczman:Celgene Corporation: Employment, Equity Ownership. Salles:BMS: Honoraria; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Autolus: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis, Servier, AbbVie, Karyopharm, Kite, MorphoSys: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Amgen: Honoraria, Other: Educational events; Epizyme: Consultancy, Honoraria; Roche, Janssen, Gilead, Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Merck: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Morschhauser:Bayer: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Epizyme: Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria; BMS: Membership on an entity's Board of Directors or advisory committees; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Abstract: Background: Salvage chemotherapy followed by high-dose therapy (HDT) and autologous stem-cell transplantation (ASCT) is the standard treatment of young patients (pts) with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL). A complete remission before ASCT is the most important prognosis factor for a better outcome. Selinexor is a first-in-class, oral selective inhibitor of nuclear export compound, an exportin 1 [XPO1] inhibitor, which, through XPO1 blockade, causes nuclear accumulation and activation of tumor suppressor proteins, reduction in oncoproteins and cancer cell apoptosis. Selinexor has been approved by the US Food and Drug Administration for the treatment of R/R DLBCL, de novo or transformed from follicular lymphoma (FL) pts after ≥2 therapies. The phase Ib SELINDA (EUDRACT 2015-005612-15) study assessed safety and efficacy of selinexor, in combination with R-GDP for pts with R/R B-cell lymphoma. Patients & methods: Eligible pts & lt; 70 years with R/R B-cell lymphoma after first or second treatment failure received every 21 days (d) 3 cycles of rituximab 375 mg/m² on d1, dexamethasone 40 mg on d1 to 4, cisplatin 75 mg/m² d1 and gemcitabine 1 gr/m² on d1 and 8 (R-GDP) in combination with escalating doses of selinexor. The starting dose (dose level 1, DL1) 40 mg was given on days 1, 3, 8, 10 (Cohort A), and from December 2017 on days 1, 8 and 15 (Cohort B). The dose-variation scheme followed a traditional "3+3" design (DL1: 40 mg; DL2: 60 mg). The primary endpoint of SELINDA was the determination of the recommended phase 2 dose of selinexor in combination with R-GDP. Secondary and exploratory endpoints were safety, efficacy, and feasibility of ASCT after selinexor-R-GDP. Results: The R2PD for selinexor in combination with R-GDP was established as 40 mg on days 1, 8, and 15 (Maerevoet, IMCL 2021#176). Between January 2017 and January 2021, 32 pts received selinexor-R-GDP. We focused on the 18 pts who received the R2PD: 15 had DLBCL, 2 FL, 1 marginal zone lymphoma. In this cohort, median age was 61 years (range 44-69); 14 pts (78%) has stage III/IV. Thirteen pts received 1 previous line before inclusion, 5 pts received 2 previous lines. At inclusion, 6 pts had refractory disease and 12 relapsed. Four pts prematurely discontinued treatment: 2 for thrombocytopenia, 1 for COVID, 1 for progression. Major adverse events (AEs) in & gt;10% of pts were reversible neutropenia (50%), thrombocytopenia (39%), and nausea (22%). No AEs leading to death were observed. Seven pts (39%) achieved a complete metabolic response (CMR), 5 pts (28%) partial metabolic response (PMR). Overall response rate (CMR+PMR) assessed at the end of treatment according to Lugano classification was 67% (12 of 18). Nine of the 15 pts (60 %) with DLBCL had metabolic response (CMR:4, PMR:5). Per protocol, peripheral stem cell collection and ASCT were optional, 4 pts of this RP2D cohort proceeded to high dose therapy (BEAM) and ASCT. Conclusion: This study established the safety profile of weekly 40mg of Selinexor in combination with R-GDP for R/R B cell lymphoma with an ORR of 67%. Reversible AEs are expected for platinum-based regimen. An ongoing randomized phase 2 study comparing R-GDP and R-GDP plus selinexor in pts with R/R DLBCL will now establish the safety and efficacy of the combination. Disclosures Casasnovas: Janssen: Consultancy; BMS: Consultancy; Gilead/Kite: Consultancy, Research Funding; TAKEDA: Consultancy, Research Funding; ROCHE: Consultancy, Research Funding; Amgen: Consultancy. Morschhauser: Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Speakers Bureau; AstraZenenca: Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees; Epizyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria; Genentech, Inc.: Consultancy; Chugai: Honoraria; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Servier: Consultancy; Genmab: Membership on an entity's Board of Directors or advisory committees. Thieblemont: Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses , Research Funding; Gilead Sciences: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb/Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Kyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Cellectis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Hospira: Research Funding; Bayer: Honoraria; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses . Feugier: Amgen: Honoraria; Janssen: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Astrazeneca: Consultancy, Honoraria.

Abstract: Introduction: For patients (pts) with relapsed indolent non-Hodgkin lymphoma (iNHL) who develop resistance to rituximab, treatment options are limited and the prognosis is poor. The open-label, randomized, Phase III GADOLIN (NCT01059630) study compared the efficacy and safety of obinutuzumab (GA101; G) plus bendamustine (B) induction, followed by G maintenance (G-B arm), with B induction (B arm; standard of care) in rituximab-refractory iNHL. The primary analysis in 396 pts (data cutoff: September 1, 2014; median observation time, 21.0 months) showed that Independent Review Committee (IRC)-assessed progression-free survival (PFS; primary endpoint) was significantly longer with G-B (median not reached [NR]) vs B (14.9 months), corresponding to a 45% reduction in risk of progression or death (hazard ratio [HR] , 0.55; 95% confidence interval [CI]: 0.40, 0.74; p=0.0001; Sehn et al. Lancet Oncol 2016). The safety profile of G-B was manageable. Here, we report the final analysis of efficacy and safety for GADOLIN (when safety follow-up for all pts had been completed [2 years' safety follow-up from last dose] ; data cutoff: November 30, 2018). Methods: Enrolled pts were aged ≥18 years with documented rituximab-refractory iNHL and an ECOG performance status of 0-2. Pts received either G 1000mg intravenously (i.v.) (Days [D] 1, 8, and 15 of Cycle [C] 1, and D1 of C2-6) plus B 90mg/m2/day i.v. (D1 and 2 of C1-6) or B monotherapy (120mg/m2/day i.v., D1 and 2 of C1-6) in 28-day cycles. Following induction, pts in the G-B arm without evidence of progression received G maintenance (1000mg i.v. every 2 months for 2 years or until disease progression). Final analysis endpoints included investigator (INV)-assessed PFS, overall survival (OS), time to new anti-lymphoma treatment (TTNT), and safety. The safety population included pts who received ≥1 dose of study treatment, excluding two pts crossing over to G-B during maintenance. Results: Of 413 iNHL pts in the ITT population (G-B, 204; B, 209), 335 (G-B, 164; B, 171) had follicular lymphoma (FL). Median (range) observation time was 57.5 (0.4-97.6) months for the G-B arm and 47.9 (0-100.9) months for the B arm (i.e. 27.6 and 35.6 months additional follow-up since the primary analysis). Median INV-assessed PFS was 25.8 months for the G-B arm vs 14.1 months for the B arm (HR, 0.57; 95% CI: 0.45, 0.73; p 〈 0.0001) in all iNHL pts (Figure 1A). Overall, fewer iNHL pts died in the G-B (84/204; 41.2%) than in the B (100/203; 49.3%) arm; median OS was 88.3 vs 65.6 months (HR, 0.77; 95% CI: 0.57, 1.03; p=0.0810; 23% risk reduction [Figure 1A]). Median TTNT was also longer with G-B vs B (38.2 vs 18.9 months, respectively [HR, 0.60; 95% CI: 0.47, 0.76] ). Results for FL pts were as follows: median PFS, 24.1 vs 13.7 months (HR, 0.51; 95% CI: 0.39, 0.67; p 〈 0.0001 [Figure 1B]); median OS, NR vs 60.3 months (HR, 0.71; 95% CI: 0.51, 0.98; p=0.0343); median TTNT, 33.6 vs 18.0 months (HR, 0.56; 95% CI: 0.43, 0.73). In the safety population (N=407; G-B, 204; B, 203), 149/204 (73.0%) of pts in the G-B arm and 134/203 (66.0%) in the B arm experienced grade ≥3 adverse events (AEs). Compared with B, grade ≥3 neutropenia (37.3% vs 30.0%) and grade ≥3 infusion-related reactions (11.3% vs 5.4%) were more frequent with G-B, and grade ≥3 thrombocytopenia (10.8% vs 15.8%) and anemia (7.4% vs 10.8%) were less frequent. The incidences of grade ≥3 infections (22.5% vs 19.2%) and grade ≥3 second malignancies (7.8% vs 5.9%) were similar between arms. The proportion of pts with serious AEs was 91/204 (44.6%) in the G-B arm and 76/203 (37.4%) in the B arm; fatal AEs were reported in 20/204 (9.8%) and 15/203 (7.4%) of pts, respectively. The most frequent AEs leading to death in the G-B vs B arms were infections (six vs seven pts, respectively) and second malignancies (eight vs four pts, respectively). Safety results in FL pts were comparable with all iNHL pts. Conclusions: Final analysis of the GADOLIN study showed that G-B was associated with a 43% reduction in the risk of progression or death compared with B in pts with rituximab-refractory iNHL and a 49% reduction in pts with FL, with a sustained and clinically relevant OS benefit in pts with FL. There were no new safety signals with longer follow-up. Acknowledgments: The GADOLIN study was sponsored by F. Hoffmann-La Roche Ltd. Third party medical writing assistance, under the direction of Laurie Sehn, was provided by Louise Profit of Gardiner-Caldwell Communications and was funded by F. Hoffmann-La Roche Ltd. Disclosures Sehn: TEVA Pharmaceuticals Industries: Consultancy, Honoraria; Lundbeck: Consultancy, Honoraria; Astra Zeneca: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Lundbeck: Consultancy, Honoraria; TEVA Pharmaceuticals Industries: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Morphosys: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Apobiologix: Consultancy, Honoraria; F. Hoffmann-La Roche/Genentech: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria; Acerta: Consultancy, Honoraria; Verastem: Consultancy, Honoraria; Morphosys: Consultancy, Honoraria; Acerta: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Kite Pharma: Consultancy, Honoraria; Janssen-Ortho: Consultancy, Honoraria; Janssen-Ortho: Honoraria; Celgene: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; TG Therapeutics: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Merck: Consultancy, Honoraria; TG Therapeutics: Consultancy, Honoraria; F. Hoffmann-La Roche/Genentech: Consultancy, Honoraria, Research Funding; Astra Zeneca: Consultancy, Honoraria; Kite Pharma: Consultancy, Honoraria; Merck: Consultancy, Honoraria. Trněný:Takeda: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Celgene: Consultancy; Gilead Sciences: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; MorphoSys: Consultancy, Honoraria; Incyte: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; F. Hoffmann-La Roche: Consultancy, Honoraria. Bouabdallah:Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Dueck:Amgen: Consultancy; Celgene: Consultancy; Janssen: Consultancy; Roche: Research Funding. Gribben:Abbvie: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Acerta/Astra Zeneca: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding. Lugtenburg:Celgene: Honoraria; Janssen-Cilag: Honoraria; Servier: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Roche: Honoraria, Research Funding, Speakers Bureau; Genmab: Honoraria. Salles:Epizyme: Consultancy, Honoraria; BMS: Honoraria; Roche, Janssen, Gilead, Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Merck: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis, Servier, AbbVie, Karyopharm, Kite, MorphoSys: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Autolus: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Other: Educational events; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events. Knapp:F. Hoffmann-La Roche Ltd: Employment. Nielsen:F. Hoffmann-La Roche Ltd: Employment, Equity Ownership. Liu:Roche Pharma Development, Shanghai, China: Employment. Cheson:Seattle Genetics: Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Trillium: Research Funding; TG Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Symbios: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol Myers Squibb: Research Funding; Portola: Research Funding; Kite: Research Funding; Gilead: Research Funding; Epizyme: Research Funding; Morphosys: Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Acerta: Consultancy, Research Funding.

Abstract: Introduction: Anti-PD-1 monoclonal antibodies (mAbs) are highly active in relapsed/refractory classical Hodgkin lymphoma (cHL), but most patients (pts) will still relapse. Given this, allogeneic stem cell transplantation (alloHSCT) remains an important option for pts after PD-1 blockade, as it offers the possibility of cure. Prior reports have suggested that alloHSCT after PD-1 mAbs may be associated with severe immune-related complications including acute graft-versus-host disease (GVHD), veno-occlusive disease (VOD) and cytokine release/febrile non-infectious syndrome (CRS). Prior studies of alloHSCT after PD-1 blockade in cHL have been limited by the small number of pts and short follow-up, preventing an accurate assessment of long-term outcomes and complications, risk factors for early toxicity, and the impact of transplant strategies such as choice of GVHD prophylaxis. We therefore assembled a large retrospective international cohort of cHL pts who underwent alloHSCT after PD-(L)1 blockade to better answer these questions, including an assessment of the impact of post-transplant cyclophosphamide (PTCy) on efficacy and toxicity. Methods: Medical records and databases were reviewed at 26 European and United States transplant centers to identify pts with cHL who underwent an alloHSCT any time after receiving a PD-1 or PD-L1 mAb. Response assessment was performed by local investigators according to Lugano 2014 criteria. Overall survival (OS), progression-free survival (PFS), cumulative incidence (CumInc) of relapse (CIR), non-relapse mortality (NRM), acute (a) and chronic (c) GVHD were estimated, as was the association between baseline variables and these outcomes. Results: Between 2014 and 2019, 150 pts were identified who underwent alloHSCT after a median of 10 (range, 1-74) doses of nivolumab (n=118), pembrolizumab (n=31), or avelumab (n=1). The median age was 31 (range 17-68) and pts had received a median of 4 (range, 2-11) lines of therapy prior to PD-(L)1 blockade. 138 pts (92%) had failed BV and 111 (74%) autologous HSCT. The best overall response to PD-(L)1 mAbs was CR for 62 pts (41%), PR for 55 (37%), SD for 17 (11%), PD for 15 (10%) and unknown for 1 (1%). Median time from last dose of PD-(L)1 mAb to alloHSCT was 80 days (range, 17-756) with 70 pts (47%) receiving intervening systemic therapy. At alloHSCT, 90 pts were in CR (60%), 45 in PR (30%), 5 in SD (3%), and 10 in PD (7%). Donors were haploidentical (n=71, 47%), matched sibling (n=29, 19%), matched unrelated (n=39, 26%), mismatched unrelated (n=7, 5%), cord blood (n=2, 1%), or unknown (n=2, 1%). Stem cell source was bone marrow (n=38, 25%), peripheral blood (n=110, 73%), or cord blood (n=2, 1%). GVHD prophylaxis included PTCy in 88 pts (59%) (69/71 (97%) with haploidentical donors; 19/79 (24%) with other donors). With a median post-alloHSCT follow-up for survivors of 23.8 months (range, 1-67), the 2y OS and PFS were 79% (95CI 71-86%) and 65% (95CI 55-73%), respectively, while the 2y CumIncs of relapse and NRM were 21% (95CI 13-29%) and 14%, (95CI, 8-22%), respectively (Fig. 1A-B). 27 pts have died, 3 due to disease and 24 to NRM, including aGVHD (n=7) and VOD (n=2). Veno-occlusive disease (VOD) occurred in 5 pts (day 100 CumInc 4%) and 29 pts (19%) developed CRS (grade 1 n=16; grade 2 n=7; grade 3 n=4; grade 4 n=2). The 6-month CumIncs of grade 2-4, grade 3-4 and grade 4 aGVHD were 39%, 16% and 8%, respectively. Hyperacute GVHD (onset ≤ 14 days after alloHSCT) occurred in 4% of pts and was fatal in 2 pts. The 2y CumInc of cGVHD was 45%. Neither receipt of & gt; 10 doses (median) of anti-PD-(L)1 mAb nor undergoing alloHSCT ≤80 days (median) after last dose of PD-(L)1 mAb were associated with PFS or OS. However, pts with a shorter time to transplant (≤80 days) appeared to have a higher risk of severe (grade 3-4) aGVHD (6m CumInc 24% vs 9%, p=0.006). Recipients of PTCy in this cohort had lower 2y CumIncs of cGVHD (34% vs 58%, p=0.01) and relapse (12% vs 31%, p=0.02), superior 2y PFS (76% vs 54%, p=0.015), and similar rates of severe aGVHD (15% vs 18%, p=0.5), 2y NRM (12% vs 16%, p=0.5), and 2y OS (82% vs 78%, p=0.6). Conclusions: With extended follow-up of a large international cohort, our results argue that alloSCT performed after PD-(L)1 mAbs is a feasible strategy associated with an excellent PFS and a very low CIR for this disease. The use of PT-Cy appears to be associated with improved outcomes and may at present represent the optimal transplant strategy in this pt population. Figure Disclosures Corradini: kite: Honoraria; Abbvie: Honoraria; Servier: Honoraria; Sanofi: Honoraria; Takeda: Honoraria; Roche: Honoraria; Novartis: Honoraria; KiowaKirin: Honoraria; Janssen: Honoraria; Gilead: Honoraria; Daiichi Sankyo: Honoraria; Celgene: Honoraria; Amgen: Honoraria. Ho:Jazz Pharmaceuticals: Research Funding; Jazz Pharmaceuticals: Consultancy; Omeros Corporation: Membership on an entity's Board of Directors or advisory committees. Jaglowski:Kite: Consultancy, Other: advisory board, Research Funding; Novartis: Consultancy, Other: advisory board, Research Funding; Juno: Consultancy, Other: advisory board; Unum Therapeutics Inc.: Research Funding. Herrera:Adaptive Biotechnologies: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Gilead Sciences: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; AstraZeneca: Research Funding; Merck: Consultancy, Research Funding; Genentech, Inc.: Consultancy, Research Funding; Pharmacyclics: Research Funding; Immune Design: Research Funding; Kite Pharma: Consultancy, Research Funding. Blaise:Jazz Pharmaceuticals: Honoraria; Sanofi: Honoraria; Pierre Fabre medicaments: Honoraria; Molmed: Consultancy, Honoraria. Hamadani:Pharmacyclics: Consultancy; Sanofi Genzyme: Research Funding, Speakers Bureau; Merck: Research Funding; Otsuka: Research Funding; Janssen: Consultancy; Medimmune: Consultancy, Research Funding; ADC Therapeutics: Consultancy, Research Funding; Takeda: Research Funding; Celgene: Consultancy. Ansell:LAM Therapeutics: Research Funding; Affimed: Research Funding; Affimed: Research Funding; Trillium: Research Funding; Trillium: Research Funding; Seattle Genetics: Research Funding; Mayo Clinic Rochester: Employment; Mayo Clinic Rochester: Employment; Bristol-Myers Squibb: Research Funding; Affimed: Research Funding; Mayo Clinic Rochester: Employment; Seattle Genetics: Research Funding; Seattle Genetics: Research Funding; Affimed: Research Funding; LAM Therapeutics: Research Funding; Mayo Clinic Rochester: Employment; Seattle Genetics: Research Funding; LAM Therapeutics: Research Funding; Bristol-Myers Squibb: Research Funding; Mayo Clinic Rochester: Employment; Affimed: Research Funding; Trillium: Research Funding; Trillium: Research Funding; Bristol-Myers Squibb: Research Funding; Regeneron: Research Funding; Affimed: Research Funding; Mayo Clinic Rochester: Employment; Bristol-Myers Squibb: Research Funding; Regeneron: Research Funding; Regeneron: Research Funding; Regeneron: Research Funding; Seattle Genetics: Research Funding; Regeneron: Research Funding; Bristol-Myers Squibb: Research Funding; Seattle Genetics: Research Funding; Seattle Genetics: Research Funding; Seattle Genetics: Research Funding; LAM Therapeutics: Research Funding; Regeneron: Research Funding; Affimed: Research Funding; Regeneron: Research Funding; Bristol-Myers Squibb: Research Funding; Trillium: Research Funding; LAM Therapeutics: Research Funding; Bristol-Myers Squibb: Research Funding; Mayo Clinic Rochester: Employment; Mayo Clinic Rochester: Employment; Regeneron: Research Funding; Trillium: Research Funding; Bristol-Myers Squibb: Research Funding; Mayo Clinic Rochester: Employment; LAM Therapeutics: Research Funding; LAM Therapeutics: Research Funding; LAM Therapeutics: Research Funding; Regeneron: Research Funding; LAM Therapeutics: Research Funding; Trillium: Research Funding; Trillium: Research Funding; Affimed: Research Funding; Bristol-Myers Squibb: Research Funding; Seattle Genetics: Research Funding; Trillium: Research Funding; Affimed: Research Funding. Nieto:Astra-Zeneca: Research Funding; Affimed: Consultancy; Affimed: Research Funding; Novartis: Research Funding. Feldman:Celgene: Honoraria, Research Funding, Speakers Bureau; Seattle Genetics: Consultancy, Honoraria, Other: Travel expenses, Speakers Bureau; Pfizer: Research Funding; AbbVie: Honoraria, Other: Travel expenses, Speakers Bureau; Portola Pharma: Research Funding; Kite Pharma: Honoraria, Other: Travel expenses, Speakers Bureau; Janssen: Honoraria, Speakers Bureau; Pharmacyclics: Honoraria, Other: Travel expenses, Speakers Bureau; Kyowa Hakko Kirin: Research Funding; Eisai: Research Funding; Bayer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Research Funding; Cell Medica: Research Funding; Roche: Research Funding; Corvus: Research Funding; Viracta: Research Funding; Trillium: Research Funding; Roche: Research Funding; Takeda: Honoraria, Speakers Bureau. McGuirk:ArticulateScience LLC: Other: Assistance with manuscript preparation; Bellicum Pharmaceuticals: Research Funding; Kite Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Gamida Cell: Research Funding; Pluristem Ltd: Research Funding; Juno Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astellas: Research Funding; Novartis: Research Funding; Fresenius Biotech: Research Funding. Mohty:Jazz Pharmaceuticals: Honoraria, Research Funding. Stamatoulas Bastard:Celgene: Honoraria; Takeda: Consultancy. Houot:Bristol Myers Squibb: Honoraria; Merck Sharp Dohme: Honoraria. Manson:Bristol Myers Squibb: Honoraria. Orvain:Incyte: Honoraria; Novartis: Honoraria; Jazz Pharmaceuticals: Other: Travel & accommodations; Pfizer: Other: Travel & accommodations. Bouabdallah:Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Frigault:Novartis: Consultancy; Kite/Gilead: Honoraria; Nkarta: Consultancy; Incyte: Consultancy; Juno/Celgene: Consultancy; Foundation Medicine: Consultancy; Xenetic: Consultancy. Chen:Takeda: Consultancy; Kiadis: Consultancy; Magenta: Consultancy; Abbvie: Consultancy; Incyte: Consultancy. Lynch:T.G. Therapeutics: Research Funding; Rhizen Pharmaceuticals S.A: Research Funding; Takeda Pharmaceuticals: Research Funding; Juno Therapeutics: Research Funding; Incyte Corporation: Research Funding; Johnson Graffe Keay Moniz & Wick LLP: Consultancy. Smith:AstraZeneca: Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck Sharp & Dohme Corp: Consultancy, Research Funding; Acerta Pharma BV: Research Funding; Portola Pharmaceuticals: Research Funding; Pharmacyclics: Research Funding; Bristol-Myers Squibb (spouse): Research Funding; Denovo Biopharma: Research Funding; Genentech: Research Funding; Ignyta (spouse): Research Funding; Incyte Corporation: Research Funding; Ayala (spouse): Research Funding; Seattle Genetics: Research Funding. Byrne:Karyopharm: Research Funding. Cohen:Hutchison: Research Funding; Astra Zeneca: Research Funding; Janssen Pharmaceuticals: Consultancy; Seattle Genetics, Inc.: Consultancy, Research Funding; Bristol-Meyers Squibb Company: Research Funding; Takeda Pharmaceuticals North America, Inc.: Research Funding; Gilead/Kite: Consultancy; Genentech, Inc.: Consultancy, Research Funding; UNUM: Research Funding; ASH: Research Funding; LAM Therapeutics: Research Funding; Lymphoma Research Foundation: Research Funding. Svoboda:AstraZeneca: Consultancy; Celgene: Research Funding; Incyte: Research Funding; Pharmacyclics: Consultancy, Research Funding; Kyowa: Consultancy; Merck: Research Funding; BMS: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding. Santoro:Bayer: Consultancy, Speakers Bureau; MSD: Speakers Bureau; Arqule: Consultancy, Speakers Bureau; Pfizer: Consultancy, Speakers Bureau; AstraZeneca: Speakers Bureau; Gilead: Consultancy, Speakers Bureau; Servier: Consultancy, Speakers Bureau; Takeda: Speakers Bureau; BMS: Speakers Bureau; Roche: Speakers Bureau; Abb-Vie: Speakers Bureau; Amgen: Speakers Bureau; Celgene: Speakers Bureau; Novartis: Speakers Bureau; BMS: Consultancy; Lilly: Speakers Bureau; Sandoz: Speakers Bureau; Eisai: Consultancy, Speakers Bureau. Armand:Sigma Tau: Research Funding; Otsuka: Research Funding; Pfizer: Consultancy; ADC Therapeutics: Consultancy; Tensha: Research Funding; Affimed: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Research Funding; Adaptive: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Infinity: Consultancy; Genentech: Research Funding. Zinzani:Roche: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Portola: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Immune Design: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sandoz: Membership on an entity's Board of Directors or advisory committees; Servier: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen-Cilag: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celltrion: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy; Eusapharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Verastem: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; MSD: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kyowa Kirin: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; TG Therapeutics: Honoraria, Speakers Bureau. Carlo-Stella:Servier: Consultancy, Honoraria, Other: Travel, accommodations; Genenta Science srl: Consultancy; Boehringer Ingelheim: Consultancy; F. Hoffmann-La Roche Ltd: Honoraria, Other: Travel, accommodations, Research Funding; Novartis: Consultancy, Research Funding; ADC Therapeutics: Consultancy, Other: Travel, accommodations, Research Funding; Sanofi: Consultancy, Research Funding; Rhizen Pharmaceuticals: Research Funding; Celgene: Research Funding; Amgen: Honoraria; AstraZeneca: Honoraria; Janssen Oncology: Honoraria; MSD: Honoraria; BMS: Honoraria; Janssen: Other: Travel, accommodations; Takeda: Other: Travel, accommodations.

Abstract: The low abundance of Hodgkin/Reed-Sternberg (HRS) cells in lymph node biopsies in classical Hodgkin lymphoma (cHL) complicates the analysis of somatic genetic alterations in HRS cells. As circulating cell-free DNA (cfDNA) contains circulating tumor DNA (ctDNA) from HRS cells, we prospectively collected cfDNA from 177 patients with newly diagnosed, mostly early-stage cHL in a monocentric study at Leuven, Belgium (n = 59) and the multicentric BREACH study by Lymphoma Study Association (n = 118). To catalog the patterns and frequencies of genomic copy number aberrations (CNAs), cfDNA was sequenced at low coverage (0.26×), and data were analyzed with ichorCNA to yield read depth-based copy number profiles and estimated clonal fractions in cfDNA. At diagnosis, the cfDNA concentration, estimated clonal fraction, and ctDNA concentration were significantly higher in cHL cases than controls. More than 90% of patients exhibited CNAs in cfDNA. The most frequent gains encompassed 2p16 (69%), 5p14 (50%), 12q13 (50%), 9p24 (50%), 5q (44%), 17q (43%), 2q (41%). Losses mostly affected 13q (57%), 6q25-q27 (55%), 4q35 (50%), 11q23 (44%), 8p21 (43%). In addition, we identified loss of 3p13-p26 and of 12q21-q24 and gain of 15q21-q26 as novel recurrent CNAs in cHL. At diagnosis, ctDNA concentration was associated with advanced disease, male sex, extensive nodal disease, elevated erythrocyte sedimentation rate, metabolic tumor volume, and HRS cell burden. CNAs and ctDNA rapidly diminished upon treatment initiation, and persistence of CNAs was associated with increased probability of relapse. This study endorses the development of ctDNA as gateway to the HRS genome and substrate for early disease response evaluation.

Abstract: Background: Mantle cell lymphoma (MCL) is characterized by a recurrent chromosomal translocation t(11;14) that leads to aberrant expression of Cyclin D1 which, together with cyclin dependent kinases 4 and 6 (CDK4/6), inhibits the retinoblastoma (Rb) tumor suppressor protein and thereby induces malignant proliferation. Abemaciclib, a cell cycle inhibitor selective for CDK4/6 (Gelbert et al, 2014), has shown single agent clinical activity against multiple human tumors including lung cancer and breast cancer (Shapiro et al, ASCO 2013; Goldman et al, ASCO 2014; Patnaik et al, ASCO 2014). Based on molecular pathogenesis and single agent activity in preclinical models of human MCL, abemaciclib was evaluated in a single arm Phase II study for patients with relapsed or refractory MCL. Methods: The primary objective of this study was to estimate the disease control rate, which includes response (complete + unconfirmed complete + partial) plus stable disease, for patients who received abemaciclib for relapsed or refractory mantle cell lymphoma (MCL). Patients were scheduled to receive abemaciclib (200 mg) orally every 12 hours on Days 1 through 28 of each 28-day cycle. Eligibility criteria permitted an unlimited number of prior systemic therapies including high dose chemotherapy with stem cell transplantation, Eastern Cooperative Oncology Group (ECOG) performance status 〈 = 2, absolute neutrophil count 〉 = 1.5 x 109/L, and platelets 〉 = 75 x 109/L. National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) v4.0 were used to grade adverse events. Response Criteria for Non-Hodgkin’s Lymphomas (Cheson et al, 1999) were used to assess clinical activity. Plasma samples for pharmacokinetics were performed both after a single oral dose and after multiple doses at steady state. Flow cytometry was used to isolate circulating MCL cells for evaluation of pharmacodynamic effect on Rb phosphorylation. Results: In this Phase II study, 22 patients with relapsed or refractory MCL received single agent oral treatment with abemaciclib. Among these patients, 91% presented at initial diagnosis with Stage III or IV disease. At the time of study entry, these patients (9 female and 13 male) had a median age of 66 years (range: 53-83), 59% had ECOG performance status of 1 or 2, and all patients had constitutional B symptoms. Eighteen patients received 〉 = 2 prior systemic therapies, and previous treatments for the overall study population included not only high dose chemotherapy with stem cell transplantation but also rituximab (96%), cyclophosphamide-based therapy (86%), cytarabine-based therapy (64%), temsirolimus (55%), and bendamustine (41%). Patients received 1-16 cycles of treatment with abemaciclib and 8 of 22 patients (36%) completed 〉 = 6 cycles. The most common possibly related treatment-emergent adverse events across all grades included diarrhea (55%, including 9% G3/4), nausea (23%, with no G3/4), vomiting (32%, with no G3/4), fatigue (18%, with no G3/4), thrombocytopenia (55%, including 32% G3/4), neutropenia (36%, including 32% G3/4), and anemia (18%, with no G3/4). Plasma concentrations of abemaciclib were comparable to those previously observed and associated with clinical activity in patients with advanced non-hematologic malignancies. For patients with at least one post-treatment radiographic evaluation, preliminary investigator assessment indicates that single agent therapy with abemaciclib was associated with stable disease for 9 patients and partial response for 5 patients, including durable disease control ( 〉 = 6 cycles) in 8 of these 14 patients with relapsed or refractory MCL. Conclusions: Abemaciclib, a cell cycle inhibitor, demonstrates evidence of durable disease control as a single agent for patients with relapsed or refractory MCL. Disclosures Hahka-Kemppinen: Eli Lilly and Company: Employment, Equity Ownership. Xiaohui Wang:Eli Lilly and Company: Employment. Brueck:Eli Lilly and Company: Employment. Caldwell:Eli Lilly and Company: Employment. Beckmann:Eli Lilly and Company: Employment, Equity Ownership. Gelbert:Eli Lilly and Company : Consultancy. Cronier:Eli Lilly and Company: Employment. Lin:Eli Lilly and Company: Employment. Li:Eli Lilly and Company: Employment. Chan:Eli Lilly and Company: Employment, Equity Ownership. Pfreundschuh:Amgen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Boerhinger Ingelheim: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Onyx: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding; Spectrum: Research Funding.

Abstract: Introduction: Plamotamab (XmAb13676) is a humanized bispecific antibody that binds both CD20 and CD3 to recruit cytotoxic T cells to kill CD20 expressing malignant cells. Interim results of an ongoing first-in-human (FIH), dose-escalation study (XmAb13676-01; NCT02924402) in subjects with relapsed/refractory (R/R) non-Hodgkin's lymphoma (NHL) are reported. Methods: The study is an FIH, multi-center, open-label, phase 1, dose-escalation study in subjects with R/R NHL with a standard 3 + 3 design. The primary objectives are to determine safety, tolerability, and the maximum tolerated dose (MTD) or recommended dose of plamotamab. Secondary objectives include preliminary anti-tumor activity and pharmacokinetics/pharmacodynamics of plamotamab. This study has 3 Parts: Part A, escalating dose cohorts that establish an initial priming dose as part of repeated weekly infusions at a fixed, weight-based dose in a 28-day cycle; Part B, with a dosing schedule consisting of a priming dose on Cycle 1 Day 1, established in Part A, followed by step-up dosing (SUD) on subsequent weeks; and Part C is an SUD regimen with flat and less frequent dosing. Cytokine release syndrome (CRS) prophylaxis with dexamethasone, antihistamine, and acetaminophen was mandated prior to each administration of plamotamab. Treatment was continued for 2 cycles or longer if there was evidence of therapeutic benefit. Results: At data cut-off (01Jul2021), 80 subjects with NHL have been treated. Subjects had a median age of 62 years (range 32-89), a median of 4 prior therapies (range 1-10), and had been diagnosed a median of 28 months (range 6-353) prior to treatment in the study. The most common treatment-related adverse event was CRS. Overall, 50 subjects (62.5%) experienced CRS, with 4 (5.0%) experiencing Grade ≥ 3 CRS. No related neurotoxicity & gt;Grade 2 has been observed. Treatment responses for NHL were assessed by the Lugano criteria or International Working Group criteria for Waldenström Macroglobulinemia. There have been 23 objective responses (43.4% overall response rate [ORR]) and 13 (38.2%) at doses of ≥ 80 µg/kg or flat dosing in all evaluable subjects with NHL and diffuse large cell B-cell lymphoma, respectively. In the efficacy-evaluable, follicular lymphoma population, at doses of 80-360 µg/kg or flat dosing, objective responses were observed in 8/10 (80%) subjects. After implementation of flat dosing, as opposed to weight-based dosing, a 50% ORR (4/8 evaluable subjects) has been observed in NHL subjects in that cohort. An MTD has not been reached, and dose escalation is ongoing. Overall, 4 out of 16 (25%) evaluable subjects with prior CAR-T therapy responded to plamotamab. Conclusions: Plamotamab demonstrated evidence of clinical activity in heavily pretreated subjects with R/R NHL. CRS was generally manageable with premedication. The study is ongoing with further optimization of dose and schedule. Figure 1 Figure 1. Disclosures Patel: Kite Pharma: Consultancy, Speakers Bureau; Genentech: Consultancy; Morphosys: Consultancy; Bristol Myers Squibb: Consultancy, Speakers Bureau; BeiGene: Consultancy; Janssen: Consultancy; AstraZeneca: Consultancy, Research Funding, Speakers Bureau; Pharmacyclics: Consultancy; Abbvie: Consultancy; TG Therapeutics: Consultancy, Speakers Bureau; MEI Pharma: Consultancy; ADC Therapeutics: Consultancy; Lilly: Consultancy. Michot: GSK: Honoraria; Celgene: Honoraria; MSD: Consultancy, Honoraria; Innate Pharma: Research Funding; Incyte: Research Funding; H3 biomedecine: Research Funding; GSK: Consultancy, Honoraria, Research Funding; Genentech: Research Funding; Gamamabs: Research Funding; Forma: Research Funding; Exelixis: Research Funding; Eos: Research Funding; Eisai: Research Funding; Debiopharm: Research Funding; Daiichi Sankyo,: Research Funding; Clovis: Research Funding; Chugai: Research Funding; Boeringer Ingelheim: Research Funding; Celgene: Research Funding; Blueprint: Research Funding; Beigene: Research Funding; Bayer: Research Funding; Argen-x: Research Funding; Amgen: Research Funding; Agios: Research Funding; Aduro: Research Funding; Abbvie: Research Funding; ASTEX: Research Funding, Speakers Bureau; Astra Zeneca: Honoraria, Research Funding; Roche: Honoraria; Bristol Myers Squibb: Consultancy, Honoraria, Research Funding. Chanan-Khan: Alpha2 Pharmaceuticals, NonoDev, Starton: Current holder of stock options in a privately-held company; Ascentage: Research Funding; Cellectar: Current equity holder in publicly-traded company; Alpha2 Pharmaceuticals: Patents & Royalties: Tabi; Ascentage, Starton, Cellectar, NonoDev, Alpha2 Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; BeiGene, Jansen, Ascentage: Honoraria; BieGene, Jansen, Ascentage: Consultancy. Ghesquieres: Janssen: Honoraria; Mundipharma: Consultancy, Honoraria; Roche: Consultancy; Celgene: Consultancy, Honoraria; Gilead Science: Consultancy, Honoraria. Byrd: Vincerx Pharmaceuticals: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Novartis, Trillium, Astellas, AstraZeneca, Pharmacyclics, Syndax: Consultancy, Honoraria; Newave: Membership on an entity's Board of Directors or advisory committees. Cartron: Roche, Celgene-BMS: Consultancy; Danofi, Gilead, Novartis, Jansen, Roche, Celgene-BMS, Abbvie, Takeda: Honoraria. Portell: Acerta/AstraZeneca: Research Funding; Xencor: Research Funding; SeaGen: Research Funding; Targeted Oncology: Honoraria; Aptitude Health: Honoraria; Abbvie: Research Funding; Pharmacyclics: Honoraria; Kite: Honoraria, Research Funding; Merck: Honoraria, Research Funding; BeiGene: Honoraria, Research Funding; Morphosys: Honoraria; TG Therapeutics: Honoraria, Research Funding; Genentech: Research Funding; VelosBio: Research Funding. Solh: Jazz Pharmaceuticals: Consultancy; Partner Therapeutics: Research Funding; BMS: Consultancy; ADCT Therapeutics: Consultancy, Research Funding. Wierda: Loxo Oncology, Inc.: Research Funding; GSK/Novartis: Research Funding; Pharmacyclics LLC, an AbbVie Company: Research Funding; Miragen: Research Funding; Sunesis: Research Funding; Gilead Sciences: Research Funding; KITE Pharma: Research Funding; Genentech: Research Funding; Janssen: Research Funding; Juno Therapeutics: Research Funding; Acerta Pharma Inc.: Research Funding; Xencor: Research Funding; AstraZeneca: Research Funding; Cyclacel: Research Funding; Oncternal Therapeutics, Inc.: Research Funding; Karyopharm: Research Funding; Genzyme Corporation: Consultancy; AbbVie: Research Funding. Johnson: Xencor: Current equity holder in publicly-traded company, Divested equity in a private or publicly-traded company in the past 24 months, Ended employment in the past 24 months. Garcha: Xencor: Current Employment, Current equity holder in publicly-traded company, Current holder of stock options in a privately-held company; Promedim: Ended employment in the past 24 months. Ribrag: AstraZeneca: Membership on an entity's Board of Directors or advisory committees; GSK: Research Funding; MSD Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Infinity Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Servier: Consultancy, Membership on an entity's Board of Directors or advisory committees; Argen-X: Research Funding; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Astex Pharmaceuticals: Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees; Nanostring: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; PharmaMar: Honoraria, Membership on an entity's Board of Directors or advisory committees; Epizyme: Honoraria, Research Funding; Roche: Membership on an entity's Board of Directors or advisory committees. Liebowitz: Xencor: Current Employment, Current equity holder in publicly-traded company, Divested equity in a private or publicly-traded company in the past 24 months. Phillips: Incyte: Consultancy, Other: received travel expenses from Incyte, Research Funding; ADCT, BeiGene, Bristol Myers Squibb, Cardinal Health, Incyte, Karyopharm, Morphosys, Pharmacyclics, Seattle Genetics: Consultancy; AbbVie: Consultancy, Research Funding; AstraZeneca: Consultancy; BMS: Consultancy, Research Funding; Genentech: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Consultancy, Research Funding.

Abstract: Introduction: Selinexor is a first-in-class Selective Inhibitor of Nuclear Export (SINE) that blocks XPO1, forcing the nuclear retention and re-activation of tumor suppressor proteins including p53, p73, FOXO, IkB and Rb. The phase 2b SADAL study included 134 patients with relapsed or refractory DLBCL with single agent oral selinexor twice weekly. The overall response rate (ORR) was 29.1%, median duration of response (DOR) was 9.3 months and the median overall survival (OS) was 9 months. Based on these data, selinexor was recently approved by the US FDA for the treatment of relapsed or refractory DLBCL, de novo or transformed from follicular lymphoma. Patients with DLBCL tend to have a number of comorbidities, including poor renal function, which can require a reduction in the dose of intensive chemotherapy as well as lenalidomide, leading to inferior outcomes. Selinexor is not metabolized nor cleared by the kidneys and has been demonstrated to be safe and active in patients with myeloma and renal dysfunction. We performed post-hoc analyses of the SADAL study to determine the efficacy and safety among patients stratified by renal function at baseline. Methods: The SADAL study is multi-center, open-label Phase 2b study that enrolled patients with DLBCL previously treated with 2-5 lines of therapy. Patients may have progressed post-stem cell therapy (SCT) or were not candidates for SCT. In this study, 60 mg of selinexor was administered twice weekly until disease progression. The primary endpoint was ORR, and other endpoints included DOR, OS, and safety assessments. For the current analysis, outcomes were assessed according to baseline renal function as estimated by the Cockroft-Gault formula for creatinine clearance (CrCl). Groups included those with reduced (CrCl ≤60 mL/min) and normal (CrCl & gt;60 mL/min) renal function. Results: Of 134 patients, 37 (28%) had a reduced baseline CrCl (≤60 mL/min) while 97 (72%) had CrCl & gt;60 mL/min. The median age of patients with reduced CrCl was 74 years with 70% ≥70 years, while the median for those with normal CrCl was 65 years, with 35% ≥70 years. De novo and transformed DLBCL showed similar renal function levels: 78% and 22% with reduced CrCl and 76% and 24% with normal CrCl. Of patients with reduced CrCl, the DLBCL subtype was 41% GCB and 57% non-GCB compared to 50% and 46% in patients with normal CrCl. The group of patients with reduced CrCl had baseline ECOG performance status of 2 in 16% vs 11% in those with normal CrCl. Treatment with selinexor demonstrated a similar ORR in patients with a baseline reduced CrCl (29.7%) versus normal CrCl (28.9%). A complete response (CR) was observed in 8 (21.6%) patients with reduced and 10 (10.3%) patients with normal CrCl. The median duration of response (DOR) in patients who had reduced CrCl was 23.0 months compared to 9.2 months in patients with normal CrCl. The median progression-free survival (PFS) was 3.5 months (95% CI 1.7, 24.8) and 2.3 months (95% CI 1.9, 3.7) and overall survival was 7.8 months and 9.1 months in patients with reduced CrCl and those with normal CrCl. The most common grade ≥3 treatment-related AEs for patients with reduced versus normal CrCl were thrombocytopenia (45.9% vs. 38.1%), nausea (5.4% vs. 6.2%), and fatigue (8.1% vs. 11.3%). There was no clinically significant increase in treatment-related serious adverse events (21.6% vs. 20.6%) and adverse events leading to discontinuation (10.8% vs. 7.2%) in patients with reduced or normal CrCl, respectively. Conclusions: Selinexor showed similar anti-DLBCL activity and tolerability in patients with relapsed/refractory DLBCL with a reduced renal function (CrCl & lt;60 mL/min) compared to those with normal (CrCl ≥60 mL/min) renal function. No dose adjustments are required in patients with renal dysfunction and DLBCL who are treated with selinexor. Disclosures Schuster: Amgen, Abbvie, Gilead, Takeda, Celgene, Pharmacyclics, Astellas, Verastem, Merck, Novartis, Takeda, Genentech,, Seattle Genetics: Other: Personal Fees; Karyopharm: Membership on an entity's Board of Directors or advisory committees. Canales:Novartis: Honoraria; Janssen: Honoraria; Novartis: Honoraria; iQone: Honoraria; Sandoz: Speakers Bureau; Karyopharm: Honoraria; Janssen: Speakers Bureau; Janssen: Honoraria; Roche: Speakers Bureau; Takeda: Speakers Bureau; Janssen: Speakers Bureau; Roche: Speakers Bureau; Sandoz: Speakers Bureau; Takeda: Speakers Bureau; Celgene: Honoraria; Roche: Honoraria; Sandoz: Honoraria; Sandoz: Honoraria; Gilead: Honoraria; Roche: Honoraria; Karyopharm: Honoraria. Westin:Novartis: Consultancy, Research Funding; Kite: Consultancy, Research Funding; Curis: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Astra Zeneca: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Morphosys: Consultancy, Research Funding; Amgen: Consultancy; 47: Research Funding. Zijlstra:Roche: Research Funding. Follows:Karyopharm, Roche, Abbvie, Astrazeneca, Janssen, BMS: Membership on an entity's Board of Directors or advisory committees. Karmali:Takeda: Research Funding; AstraZeneca: Speakers Bureau; Karyopharm: Honoraria; BeiGene: Speakers Bureau; BMS/Celgene/Juno: Honoraria, Other, Research Funding, Speakers Bureau; Gilead/Kite: Honoraria, Other, Research Funding, Speakers Bureau. Kalakonda:Gilead, Janssen, Karyopharm: Honoraria; Verastem, Gilead, Celgene, Roche: Research Funding. Goy:AbbVie: Research Funding; Celgene: Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Other: leadership role, Research Funding; Acerta: Consultancy, Honoraria, Other: leadership role, Research Funding; MD Anderson: Research Funding; Xcenda: Consultancy; Kite, a Gilead Company: Consultancy, Current equity holder in publicly-traded company, Honoraria, Other: leadership role, Research Funding; Regional Cancer Care Associates/OMI: Current Employment; Bayer: Research Funding; PracticeUpdate Oncology: Consultancy; RCCA/OMI: Current Employment; Morphosys: Research Funding; Karyopharm: Research Funding; Genentech/Roche: Research Funding; Constellation: Research Funding; CALBG: Research Funding; Infinity Verastem: Research Funding; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: leadership role, Research Funding; COTA: Consultancy, Current equity holder in publicly-traded company, Other: leadership role; Hackensack UMC and University of Nebraska: Research Funding; Infinity: Research Funding. Casasnovas:Takeda: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Gilead: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding; Roche: Consultancy, Honoraria, Other: travel, accomodations, expenses, Research Funding; Abbvie: Consultancy, Honoraria; MSD: Consultancy, Honoraria; Amgen: Consultancy, Honoraria. Thieblemont:Cellectis: Speakers Bureau; Roche, Amgen, Kyte Gilead, Celgene, Abbvie, Novartis, Cellectis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support; Roche, Hospita: Research Funding. Cavallo:Takeda, Janssen: Membership on an entity's Board of Directors or advisory committees; Gilead: Other: Speaker Fee. Hill:Celgene: Consultancy, Honoraria, Research Funding; Genentech: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria; Kite, a Gilead Company: Consultancy, Honoraria, Research Funding; AstraZenica: Consultancy, Honoraria, Research Funding; Beigene: Consultancy, Honoraria, Research Funding; Pharmacyclics: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria, Research Funding; Takeda: Research Funding. Tilly:BMS: Honoraria. Jaeger:Novartis: Consultancy, Honoraria, Research Funding; Gilead: Honoraria, Research Funding; BMS/Celgene: Consultancy, Honoraria, Research Funding; Karyopharm: Honoraria; AbbVie: Honoraria; F. Hoffmann-La Roche: Honoraria, Research Funding; Miltenyi: Consultancy, Honoraria; CDR Life AG: Consultancy, Research Funding. Gurion:JC Health CARE: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Takeda Pharmaceuticals: Consultancy, Honoraria; Gilead Sciences: Consultancy, Honoraria; Medison: Consultancy, Honoraria. Caimi:Celgene Corp: Other: Incyte Corporation - Ownership - Pharmacyclics, Inc. - Ownership - Celgene Corp. - Other, Speakers Bureau; ADC Therapeutics: Research Funding; Genentech: Research Funding. Martin:Kite: Consultancy; Morphosys: Consultancy; I-MAB: Consultancy; Janssen: Consultancy; Sandoz: Consultancy; Regeneron: Consultancy; Incyte: Consultancy; Karyopharm: Consultancy, Research Funding; Teneobio: Consultancy; Celgene: Consultancy; Bayer: Consultancy; Cellectar: Consultancy; Beigene: Consultancy. Davies:Roche, Acerta Pharma, AstraZeneca, Celgene, Gilead, ADC Therapeutics, Gilead: Research Funding; Roche, Celgene, Kite Pharma, Acerta, Karyopharma, Regeneron, Incyte: Consultancy; Roche: Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Celegene, Roche, Kite Pharma, Celegene: Honoraria. Smith:TG Therapeutics: Consultancy, Research Funding; Janssen: Consultancy; Celgene: Consultancy, Research Funding; BMS: Consultancy; Karyopharm: Consultancy, Research Funding; FortySeven: Research Funding; Pharmacyclics: Research Funding; Acerta: Research Funding; Genentech/Roche: Consultancy, Other: Support of parent study and funding of editorial support, Research Funding. Collins:BeiGene: Consultancy; MSD: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Speakers Bureau; Taekda: Consultancy, Honoraria, Other: travel, accommodations, expenses, Speakers Bureau; BMS: Consultancy, Honoraria, Research Funding, Speakers Bureau; Pfizer: Honoraria; ADC Therapeutics: Consultancy, Honoraria; Celleron: Consultancy, Honoraria, Research Funding; Gilead: Consultancy, Honoraria, Speakers Bureau; Celgene: Research Funding; Roche: Consultancy, Honoraria, Other: travel, accommodations, expenses , Speakers Bureau; Amgen: Research Funding. Salles:Epizyme: Consultancy; Gilead: Consultancy, Honoraria, Other: Participation in educational events; Abbvie: Consultancy, Honoraria, Other: Participation in educational events; Janssen: Consultancy, Honoraria, Other: Participation in educational events; Kite: Consultancy, Honoraria, Other; Debiopharm: Consultancy; Celgene: Consultancy, Honoraria, Other: Participation in educational events; Karyopharm: Consultancy; Genmab: Consultancy; Amgen: Honoraria, Other: Participation in educational events; Autolus: Consultancy; MorphoSys: Consultancy, Honoraria, Other; Novartis: Consultancy, Honoraria, Other; F. Hoffman-La Roche Ltd: Consultancy, Honoraria, Other; Bristol Myers Squibb: Consultancy, Other; Takeda: Consultancy, Honoraria, Other. Ma:Karyopharm: Current Employment, Current equity holder in private company. Corona:Karyopharm: Current Employment. Saint-Martin:Karyopharm: Current Employment. Joshi:Karyopharm Therapeutics Inc: Consultancy. Chamoun:Karyopharm: Current Employment. Wang:Curis: Ended employment in the past 24 months; Karyopharm: Current Employment. Shah:Karyopharm: Current Employment, Current equity holder in publicly-traded company. Shacham:Karyopharm: Current Employment, Current equity holder in publicly-traded company, Patents & Royalties: (8999996, 9079865, 9714226, PCT/US12/048319, and I574957) on hydrazide containing nuclear transport modulators and uses, and pending patents PCT/US12/048319, 499/2012, PI20102724, and 2012000928) . Kauffman:Karyopharm Therapeutics Inc: Current Employment, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees.

Abstract: We previously reported a 93% CR rate in patients with Philadelphia positive acute lymphoblastic leukemias (Ph+ ALL) treated with an imatinib (Glivec®) based induction (DIV regimen) (Rea et al. Leukemia, 2006;20:400–3). We decided to further confirm these results in a larger prospective cohort of patients and to evaluate the combination of imatinib and Pegasys® for patients in CR not eligible for hematopoietic stem cell transplantation (HSCT). Patients not previously exposed to imatinib and with resistant or refractory Ph+ ALL, lymphoid blast crisis CML (LBC CML) or with de novo Ph+ ALL and aged over 55y were eligible. The DIV regimen consisted in one IV injection of vincristine 2 mg combined with 2 days of dexamethasone 40 mg PO repeated weekly for 4 weeks as induction and then monthly for 4 months as consolidation. Imatinib was administered at 800 mg per day during the induction period and at 600 mg/d continuously with 6 mercaptopurine during consolidation. Patients in CR not eligible for HSCT were allocated to maintenance therapy consisting in weekly SC injection of Pegasys® 45 μg and continuous administration of imatinib 400 mg per day for 2 years. 54 patients (median age 62y, 22 to 83) were included (22 resistant or refractory Ph+ ALL, 3 relapsed Ph+ ALL, 4 LBC CML and 25 elderly Ph+ ALL). The median follow up was 18 months. The overall CR rate after induction was 85%. 42 patients were eligible for post consolidation therapy: 18 patients received HSCT (10 allogenic HSCT including 9 out of the 15 patients aged under 55y and 8 autologous HSCT). 18 out of 24 patients (75%) without HSCT started the maintenance therapy. Reasons for not being in maintenance were relapse in one case, septic death in 3 cases and toxicity in 2 cases. The interval from CR to HSCT was 5.8 months in median (2.6 to 11.3). The medain interval from CR to maintenance was 5.4 months (5.2 to 6.7). The median survival of the transplanted group of patients was 29.9 months compared to 27.9 months for patients treated with the maintenance schedule (p=0,98). Six patients (33%) relapsed in the HSCT group and 7 (38.8%) in the maintenance group. Grade 2 to 4 neutropenia and/or thrombocytopenia were observed in 33% of cases during maintenance therapy leading to transient interruption of Pegasys® injections. Extra haematological grade 3 to 4 toxicities were infrequent (1 papillary oedema and two infections). We confirm here the high CR rate obtained in Ph+ acute lymphocytic leukemias with the DIV regimen, without the need of intensive chemotherapy. Maintenance therapy with Pegasys® and imatinib represents an alternative approach for patients not eligible for HSCT and was associated with a median survival of 27.9 months in this study.

Abstract: Background: Treatment options for patients (pts) with relapsed or refractory indolent non-Hodgkin lymphoma (iNHL) are limited. GADOLIN (NCT01059630) is an open-label, randomized, Phase 3 trial comparing the efficacy and safety of obinutuzumab (GA101; GAZYVA/GAZYVARO; G) plus bendamustine (B) induction, followed by G maintenance (G-B arm), with B induction (standard of care) in rituximab-refractory iNHL pts. In the primary analysis, which involved all pts enrolled as of September 1, 2014 (n=396; median observation time, 21.0 months [mo]), median Independent Review Committee (IRC)-assessed progression-free survival (PFS; primary endpoint) was longer in the G-B arm (194 pts; median not reached) than in the B arm (202 pts; 14.9 mo), with a 45% reduction in risk of progression or death (HR 0.55; 95% CI 0.40, 0.74; p=0.0001). Investigator (INV)-assessed PFS was also significantly longer in the G-B arm, but overall survival (OS) data were immature. Safety profiles were comparable. The most common grade ≥3 adverse events (AEs) were neutropenia, thrombocytopenia, anemia, and infusion-related reactions (IRRs). Seventeen additional pts were enrolled after the data cut-off for the primary analysis. Here, we report updated time-to-event and safety results from a planned analysis of all pts (n=413) using a data cut-off of April 1, 2016. Methods: Enrolled pts were aged ≥18 years (yrs) with documented rituximab-refractory iNHL and an ECOG performance status of 0-2. Pts received either G 1000mg i.v. (days [D] 1, 8, and 15 of cycle [C] 1, and D1 of C2-6) plus B 90mg/m2/day i.v. (D1 and 2 of C1-6), or B monotherapy (120mg/m2/day i.v., D1 and 2 of C1-6); each cycle was 28 days. Following induction, pts in the G-B arm without evidence of progression received G maintenance (1000mg i.v. every 2 mo for 2 yrs or until disease progression, whichever occurred first). In the current analysis, assessments included INV-assessed PFS, OS, time to new anti-lymphoma treatment (TTNT), and safety. Efficacy assessment was performed on the intent-to-treat (ITT) population. Safety analysis included all pts who received any study treatment, excluding 2 pts who crossed over to G-B during maintenance. Results: Of 413 iNHL pts in the ITT population (G-B, 204; B, 209), 335 (G-B, 164; B, 171) had FL. Baseline characteristics of the ITT population were balanced between arms. Median number of prior regimens was 2 in both arms (pts with ≤2 prior regimens: G-B, 80.4%; B, 77.5%). Most pts were refractory to their last regimen (G-B, 92.2%; B, 92.3%). After 31.8 mo median follow-up, median INV-assessed PFS was 25.8 mo in the G-B arm and 14.1 mo in the B arm; HR was 0.57 (95% CI 0.44, 0.73; p 〈 0.0001), i.e. a 43% reduction in risk of progression or death for G-B relative to B. Fewer pts died in the G-B arm (25.5%) than the B arm (34.9%), with a HR for OS of 0.67 (95% CI 0.47, 0.96; p=0.0269; risk reduction, 33%; Figure 1A); median OS was not reached for either arm. Results for FL pts were consistent with those for ITT pts (median PFS: 25.3 vs. 14.0 mo [HR 0.52; 95% CI 0.39, 0.69; p 〈 0.0001]; median OS: not reached vs. 53.9 mo [HR 0.58; 95% CI 0.39, 0.86; p=0.0061; Figure 1B] ). Median TTNT was also longer in the G-B arm than in the B arm (ITT pts: 40.8 vs. 19.4 mo, respectively [HR 0.59; 95% CI 0.45, 0.77]; FL pts: 33.6 vs. 18.0 mo, respectively [HR 0.57; 95% CI 0.43, 0.75] ). The overall safety profile of G-B remained consistent with results of the primary analysis. In the ITT population, there were more grade ≥3 AEs with G-B than with B (72.5% vs. 65.5%, respectively), notably neutropenia (34.8% vs. 27.1%) and IRRs (9.3% vs. 3.5%); grade ≥3 thrombocytopenia (10.8% vs. 15.8%) and anemia (7.4% vs. 10.8%) were less frequent in the G-B arm, while grade ≥3 infections (22.5 % vs. 19.2%) and secondary malignancies (5.9% vs. 5.4%) were reported with a similar incidence. Serious AEs were more frequent in the G-B arm (43.6% vs. 36.9%), but the incidence of grade 5 (fatal) AEs was similar (7.8% vs. 6.4%). Safety results in FL pts were comparable with those in all iNHL pts. Conclusions: Updated analysis of the GADOLIN study with ~10 mo additional follow-up confirms the previously reported PFS benefit of G-B over B in pts with rituximab-refractory iNHL, and demonstrates a significant improvement in OS in the G-B arm. No new safety signals were detected. Figure 1. OS results: A) ITT population; B) FL pts Figure 1. OS results: A) ITT population; B) FL pts Disclosures Cheson: Roche-Genentech: Consultancy; Pharmacyclics: Consultancy, Research Funding; Gilead: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Astra Zeneca: Consultancy; Spectrum: Consultancy; Astellas: Consultancy; Teva: Research Funding. Trněný:Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Dueck:Roche: Research Funding; Celgene: Honoraria, Research Funding; Onyx: Research Funding; Lundbeck: Honoraria, Research Funding. Lugtenburg:Celgene: Consultancy; Mundipharma: Consultancy; Servier: Consultancy; Roche: Consultancy; Takeda: Consultancy. Salles:Mundipharma: Honoraria; Gilead: Honoraria, Research Funding; Roche/Genentech: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria. Fingerle-Rowson:F. Hoffmann-La Roche Ltd: Employment, Equity Ownership. Mattiello:F. Hoffmann-La Roche Ltd: Employment. Wassner-Fritsch:elisabeth.wassner_fritsch@roche.com: Employment. Sehn:Roche/Genentech: Consultancy, Research Funding; Celgene: Consultancy; Gilead: Consultancy; Janssen: Consultancy; Pfizer: Consultancy; Amgen: Consultancy; Seattle Genetics: Consultancy; Abbvie: Consultancy; Lundbeck: Consultancy.