Abstract: Posterior reversible encephalopathy syndrome features reversible cortical neurologic dysfunction and characteristic findings on brain imaging studies. This syndrome can be caused by several agents including traditional chemotherapy and immunosuppressive drugs. Targeted therapies such as agents binding vascular endothelial growth factor/VEGFR, CD20 and cytotoxic T-cell lymphocyte antigen 4 (CTLA-4) antigens are also among the culprits. Vemurafenib is a BRAF gene inhibitor that has not been previously linked with posterior reversible encephalopathy syndrome. We report herein the first such case and believe that further studies confirming this association are warranted. We further review the existing posterior reversible encephalopathy syndrome cases associated with targeted therapies in the scientific literature.

Abstract: Multiple CD19-directed therapies are available for the treatment of relapsed and refractory (R/R) DLBCL, including CAR T cells, tafasitamab/lenalidomide (TL), and loncastuximab tesirine (lonca-T) (Sermer D., Blood Rev 2023). However, there are few data available on the efficacy of sequential CD19-directed therapies. We performed a retrospective study evaluating all patients with R/R LBCL treated consecutively with TL at 11 institutions from 8/2020 to 8/2022, identifying 178 patients. In this study, we specifically evaluate outcomes in patients who received anti-CD19 therapy prior to or after TL. The primary outcome of interest was progression-free survival (PFS) in TL recipients who previously received CD19-directed CAR T therapy, with overall response rate (ORR), complete response rate (CRR), and overall survival (OS) also evaluated. Outcomes of lonca-T and CAR T after TL therapy were evaluated. Data on CD19 expression was assessed on biopsies after TL; this was determined locally using flow cytometry or immunohistochemistry per institutional protocols. In subgroup analyses, ORR and CRR were compared using Fisher's exact test. PFS and OS were estimated using the Kaplan-Meier method, with differences tested using the log-rank test. Of 178 patients who received TL, 52 had received prior anti-CD19 CAR T therapy, at a median of 7.4 months before TL (Table 1). Median PFS was lower in prior CAR T recipients (1.6 mo, 95% CI 1.1-2.5) vs no prior CAR T (2.1 mo, 95% CI 1.8-3.2), with hazard ratio 1.46 (p = 0.04; Figure 1). Best ORR was lower in patients with prior CAR T exposure (15% vs 33%, p = 0.02) though CRR was not significantly different (15% vs 18%, p = 1.0). We specifically evaluated TL outcomes based on prior response to CAR T, given the previously identified association of refractory disease with poor TL outcomes (Qualls D et al., presented at ASH 2022). Of 19 patients who had progressive disease more than 6 months after CAR T, ORR and CRR to TL therapy were 31.6% (all responses were CRs); in 33 patients with refractory disease (less than CR or relapse within 6 months) after CAR T, ORR and CRR to TL were significantly lower, at 6.1% (p = 0.04). Median PFS after TL was shorter in CAR-refractory than CAR-relapsed disease, at 1.4 vs 3.5 months (HR 2.2, p = 0.02). Of 88 patients who received therapy after TL, 20 (23%) received lonca-T and 14 (16%) received CAR T. Data on survival and initiation of new treatment after CAR T or lonca-T was available, but response and progression data after CAR T or lonca-T therapy is pending. These data allowed an estimate of OS and event-free survival (EFS), defined as survival without initiation of a new treatment after CAR T or lonca-T. With a median 3.9 months' follow-up, median EFS after CAR T administration was 3.7 months (95% CI, 0.9 - 6.5), and median OS was 8.1 months (95% CI, 0.6 - 15.7). In patients who received lonca-T, with median 2.7 months' follow-up from initiation, median EFS was 2.8 months (95% CI, 0.9 - 4.7), and median OS was 3.5 months (95% CI, 1.2 - 5.7). When comparing CAR T and lonca-T to polatuzumab vedotin- or chemotherapy-based therapies after TL, there were no significant differences in OS or EFS. In patients who discontinued TL, 24 had a biopsy a median of 18 days after the last dose of tafasitamab. Of these, 13 (54%) were CD19-positive and 11 (46%) were CD19-negative. All samples obtained more than 21 days after tafasitamab (6/6) were CD19-positive, while 46% obtained within 21 days were CD19-positive. These time-dependent findings may reflect “epitope masking” by tafasitamab rather than CD19 loss, reflecting other recent reports (Fitzgerald K., Leuk Lym 2022; Duell J., Leuk Lym 2022). In patients receiving TL after CAR T, responses and PFS were lower than in patients without prior CAR T therapy; however, with disease that was not refractory to prior CAR T, results were similar to patients who had not had prior CAR T. This may reflect that refractory disease, regardless of prior therapy, is associated with shorter PFS, though the possibility of CD19-mediated mechanisms of resistance remains. Modest EFS and OS were seen in patients receiving CAR T therapy or lonca-T after already receiving TL, though this may also reflect the high-risk disease characteristics of this cohort. Overall, in a high-risk, real-world cohort of TL-treated patients, these data suggest that some patients may benefit from subsequent CD19-directed therapies, but better therapeutic options are needed.

Abstract: Background: Recently, large B-cell lymphomas (LBCLs) have undergone major shifts in classification and treatment paradigm, particularly with the advent of CD19-targeted chimeric antigen receptor T cell therapy (CAR-T). Initially approved as third-line treatment in LBCL in 2017, as of early 2022 CAR-T is indicated for second-line therapy (2L) in patients with relapsed or refractory (R/R) disease within 12 months of frontline treatment or who are not candidates for autologous stem cell transplant (ASCT). Given this quickly changing landscape, we aimed to describe disease characteristics, patterns of care, and survival outcomes in patients with R/R LBCL receiving two or more lines of systemic therapy across modern treatment eras. Methods: We developed a database of patients with R/R LBCL from 8 U.S. academic centers in the Lymphoma Epidemiology of Outcomes (LEO) Cohort study (NCT02736357) and Consortium for Real World Evidence (CReWE). Unlike the SCHOLAR-1 dataset (M Crump et al, Blood 2017), our cohort included any patient receiving 2L, regardless of timing of progression/relapse. For this analysis, eligible patients were aged ≥18 years and received 2L between 2002-2022. Patients with histologic transformation, post-transplant lymphoproliferative disorder, primary CNS lymphoma, primary mediastinal B-cell lymphoma, Burkitt lymphoma, or plasmablastic lymphoma were excluded. Prognostic factors, therapy details (including intent for ASCT and/or CAR-T), and outcomes, including treatment response, event-free survival (EFS), and overall survival (OS), were abstracted for all lines of therapy. Treatment eras were defined as pre-CAR-T (2002-2010), CAR-T available via clinical trial (2011-2017), and post-FDA approval of CAR-T (2018-2022). Results: Of 1760 patients initiating 2L for R/R disease, 1523 were eligible for analysis. Median age at start of 2L was 62 (interquartile range [IQR] 53-70), and 65% were male; 11% were non-White, and 8% were Hispanic. High-grade subtypes comprised 16% of all cases. IPI was available for 1013 patients at time of 2L therapy, with 54% having IPI 3-5. Median time from diagnosis to 2L was 8.7 months (IQR 5.6-18.5), with 834 patients not having achieved complete response (CR) to 1L, 285 patients relapsing & lt;12 months after 1L, and 404 patients relapsing ≥12 months after 1L. The median number of total lines of therapy received was 4 (range 2-18), with 586 and 347 receiving ASCT and CAR-T, respectively, at any line of treatment. At a median follow-up of 48 months from the start of 2L, 926 patients (61%) had died. Progressive lymphoma was the primary cause of death in 75% of deceased patients, with 8% of reported deaths due to therapy. 2L was received at an academic medical center in 83% cases, and 209 patients (14%) received 2L on a clinical trial. ASCT and/or CAR-T was planned at 2L for 989 patients (65%), of whom 463 ultimately received ASCT, 88 received CAR-T, and 21 received allogeneic transplant at 2L. 494 patients were not considered for ASCT or CAR-T at 2L, and 40 were unknown for ASCT/CAR-T intent. Breakdown by treatment era (n = 1518 with available treatment start date) is shown in the Table. Median EFS from start of 2L was 4.2 months (95% confidence interval [CI]: 3.8-4.8). Median OS from start of 2L was 18 months (95% CI: 17-22), and 2- and 5-year OS estimates were 46% (95% CI: 44-49%) and 35% (95% CI: 33-38%), respectively. EFS and OS improved significantly for patients initiating 2L between 2011-2017 comp ared to 2002-2010. However, EFS and OS in the 2018-2022 era remained similar to 2011-2017 (Figure). Conclusions: To our knowledge, this study is the first-ever large-scale attempt to describe patterns of care and outcomes in LBCL 2L in the modern era, inclusive of all treatment approaches. The rich and unique LEO CReWE dataset captures evolving practice approaches over time in terms of both intent for and receipt of cellular therapies. Likely reflecting the rapid development of many novel immune effector cell products and bispecific antibodies, we observed increased enrollment on 2L clinical trials in the 2018-2022 period, including a substantial proportion of patients receiving CAR-T in 2L. Importantly, survival increased in treatment eras during which CAR-T was available. Ongoing analyses of factors associated with improved survival will be presented at the meeting.

Abstract: Background: Polatuzumab vedotin (Pola), an antibody drug conjugate targeting CD79b received FDA approval in combination with bendamustine and rituximab (Pola-BR) in June 2019. With CAR-T as destination therapy, the option of Pola-BR appears appealing with its superior efficacy and lack of potential interference with CAR-T due to different target antigens. However, clinical concerns remain regarding prolonged lymphopenia associated with benda and CAR-T manufacturing if used before apheresis. We reviewed the single center experience of all patients with exposure to polatuzumab around CAR-T for R/R aggressive NHL treated at Mayo Clinic Rochester. Methods: A review of patients that received at least one dose of Pola with the intent to proceed to CAR-T between July 1, 2019 and March 31st, 2021 at Mayo Clinic, Rochester were included. Response to therapy was based on 2014 Lugano criteria. Overall survival (OS) was defined as the time from CAR-T infusion to death, and event-free survival (EFS) as the time from CAR-T infusion to disease progression, next treatment, or death. Survival curves were calculated using Kaplan-Meier estimates, and were compared between subgroups using the log-rank test. Cox regression was used for multivariate analysis (MVA). Results: A total of 22 patients were identified during the study period. Of these 18 (82%), made it to CAR-T infusion (17 axi-cel, and 1 -tisa cel). 3 patients died due to progressive disease (PD) before CAR-T and one achieved complete remission (CR). In the pre-CAR-T Pola cohort (n = 22), the median age was 65.5 years (39-73), 50% were males, 96% had advanced stage and IPI ≥ 3. Median prior lines of treatment were 4.5 (2-6), 73% had primary refractory disease and 50% had myc rearrangement. 19 (86%) patients received Pola as bridging therapy and 8 were exposed to Pola before T-cell apheresis. Bendamustine was included in the treatment for 79% (15/19) for bridging therapy and 63% (5/8) with exposure pre-apheresis. For those in the bridging group, the overall response rate (ORR) was 26% (5/19), with one patient achieving CR with Pola-BR. Disease control (defined as those in a partial response [PR] or stable disease [SD]) was seen in 47% (9/19) patients. One of the 8 patients with pre-apheresis exposure to Pola, required an additional attempt at CAR-T manufacturing after the initial failure. At a median follow up of 48 weeks, the EFS and OS in 18 patient cohort with pre-CAR-T Pola exposure were 6.7 weeks (95% CI, 4.3-not reached [NR]) and 15 weeks (95% CI, 9.7-NR), respectively. At the data cut off (7/25/2021), 78% patients had died. As traditional chemo for bridging is a particularly poor prognostic group, we compared Pola-BR bridging group (n = 15), to other traditional chemo bridge group (n = 16) in our CAR-T database. Both groups had comparable baseline characteristics as shown in Table 1 except for higher proportion of patients with B-symptoms in the Pola-BR group at time of CAR-T. There was also no difference in the inflammatory markers (CRP and ferritin) at LD or peak level after CAR-T. Table 2 shows outcomes between the 2 groups with comparable any grade CRS, neurotoxicity, pre and post CAR-T infection rates. Best response ORR to CAR-T was higher in the other chemo group vs. Pola BR (81.2% vs. 33%, p = 0.027). There was a significant difference in the 6-month OS rate (other 81.3% [95%CI, 54.5-96] vs. pola 33.3% [95%CI, 11.8- 61.6], p = 0.007) but no significant difference in the 6-month EFS rate (other 37.5% [95%CI, 15.2-64.6%] vs. pola 13.3% [95%CI, 1.7-40.5%] p = 0.12) between the 2 groups (figure 1). On univariate analysis within the chemo type bridging cohort (Pola-BR + other traditional chemo, n = 31), presence of B-symptoms (HR 4.72, p = 0.002), ECOG PS & gt; 2 at CAR-T (HR 6.75, p = 0.0008), and type of bridge therapy (pola HR 6.57, p = 0.009) were associated with worse OS whereas a response to bridge (PR+SD, HR 0.39, 0.031) was favorable. On MVA, association was maintained for bridge type (pola, p & lt;0.001) and response to bridge (p & lt;0.001). Discussion: Pola based bridge was feasible in this US based cohort without significant issues with CAR-T manufacturing or increased infection rates. However, in this retrospective analysis, use of Pola-BR was associated with inferior outcomes compared to other traditional chemotherapy options. Future studies are required to elucidate whether these difference in outcomes stem from a biological basis versus bias in patient selection. Figure 1 Figure 1. Disclosures Wang: TG Therapeutics: Membership on an entity's Board of Directors or advisory committees; MorphoSys: Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding; Eli Lilly: Membership on an entity's Board of Directors or advisory committees; LOXO Oncology: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Genentech: Research Funding; InnoCare: Research Funding. Paludo: Karyopharm: Research Funding. Bennani: Kymera: Other: Advisory Board; Vividion: Other: Advisory Board; Kyowa Kirin: Other: Advisory Board; Daichii Sankyo Inc: Other: Advisory Board; Purdue Pharma: Other: Advisory Board; Verastem: Other: Advisory Board. Ansell: Bristol Myers Squibb, ADC Therapeutics, Seattle Genetics, Regeneron, Affimed, AI Therapeutics, Pfizer, Trillium and Takeda: Research Funding. Lin: Bluebird Bio: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Merck: Research Funding; Kite, a Gilead Company: Consultancy, Research Funding; Novartis: Consultancy; Janssen: Consultancy, Research Funding; Juno: Consultancy; Vineti: Consultancy; Takeda: Research Funding; Gamida Cell: Consultancy; Legend: Consultancy; Sorrento: Consultancy.

Abstract: Background: Although marginal zone lymphoma (MZL) typically exhibits an indolent course, transformation to diffuse large B-cell lymphomas (DLBCL) is associated with a poorer outcome and remains a clinical challenge in managing patients with MZL. The limited existing literature reports various cumulative incidence rates, ranging from 2.5% and 4.7% (Finnish Cancer Registry, 1995-2018) to 6.6% and 8.4% (Florida Cancer Registry, 1995-2016) at 5 and 10-years, respectively, likely in part driven by varying study designs, ascertainment, and study population. Similarly, reported outcomes after transformed MZL (tMZL) have been variable. We evaluated the cumulative incidence of histological transformation (HT) to LBCL in a well-characterized prospective cohort of MZL patients from the upper Midwest, USA, and overall survival (OS) after transformation. Methods: Patients ≥ 18 years old with newly diagnosed MZL were prospectively enrolled in the University of Iowa/Mayo Clinic Molecular Epidemiology Resource (MER) cohort from 2002-2015. Clinical and treatment data were abstracted from medical records using a standard protocol. Patients were actively followed for retreatment, transformation, and death through 2022. Pathology was classified according to WHO 4/4R, including all transformations. The cumulative incidence of HT to LBCL was determined using death as a competing risk. Time to HT (TTHT) was defined as time from the date of MZL diagnosis to the date of transformation. We evaluated potential predictors of HT using a stepwise approach, and derived hazard ratios (HR) and 95% confidence intervals (CI) from Cox proportional hazards models. To assess predictors of OS after HT, patients ≥ 18 years old with newly diagnosed tMZL (into DLBCL) at Mayo Clinic between 1995 and 2002 (N=7) were combined with the MER cases. Results: We identified 524 patients with MZL in the MER cohort: 362 extranodal (EMZL; lung 18%, stomach 16%, orbit 13%, parotid 10%, skin 10%), 84 splenic (SMZL), and 78 nodal (NMZL). The median age at diagnosis was 63 years (range 18-92); 56% were female, and 83% were non-Hispanic white. During a median follow-up of 18.8 years (95% CI 16.7, NA), there were 25 HT (including 8 patients under observation) and 158 deaths. Eight Ten-year OS was 67% and 77% in the groups with and without HT, respectively. The overall cumulative incidence of HT was 1.5% at 2 years after diagnosis, 2.9% at 5 years, 4.5% at 10 years, and 5.7% at 15 years (Panel 1). The cumulative incidence of HT varied by subtype (e.g., at 5 years: 2%, 4% and 6%, in EMZL, NMZL and SMZL, respectively; Panel 2). The median time to HT also varied by subtype: 76 months (interquartile range (IQR) 43, 81) for EMZL, 30 months (IQR 16, 52) for SMZL, and 18 months (IQR 14, 23) for NMZL. In univariable analysis, predictors of HT were Stage III/IV (HR=3.4, 95% CI 1.36-8.53, p=0.009), elevated LDH (HR=2.98, 95% CI 1.25-7.12, p=0.014), and presence of ≥2 extranodal sites (HR=2.69, 95% CI 1.22-5.94, p=0.014). In multivariable analysis, elevated LDH was the only non-composite predictor of HT (HR=2.65, 95% CI 1.08-6.52, p=0.034). MALT-IPI score 2-3 (HR=3.61, 95% CI 1.06-12.25, p=0.040) and FLIPI score 3-5 (HR=2.19, 95% CI 1.22-8.22, p=0.018) also predicted HT. We analyzed OS after HT in 32 cases of tMZL (21 tEMZL, 7 tSMZL, 4 tNMZL). At HT, median age was 68 years (range 39-89); 24 (80%) patients presented with stage III/IV disease, 11 (58%) with elevated LDH, 12 (55%) with hemoglobin & lt;12g/dL, 3 (14%) with platelet count & lt;100x10 9/L and 9 (39%) with biopsy-proven bone marrow involvement. Twenty-six (81%) were treated with a systemic therapy, mainly CHOP-backbone therapy (R-CHOP n=13, CHOP n=4, R-EPOCH n=3, lenalidomide-R-CHOP n=1). Among these patients, the overall response rate was 85% (n=22/26). Three of the 4 non-responders died within 1 year. At last follow-up, 18/32 (56%) patients had died, and 6/13 (46%) alive patients had relapsed (MZL 3/6, DLBCL 3/6). After HT, 2-, 4- and 10-year OS were 76%, 55% and 55%, respectively. In univariable analysis, the only predictor of OS at HT was age ≥70 (HR 3.57 ,95% CI 1.34-9.48, p=0.011). Conclusion: In this North American prospective cohort of mainly non-Hispanic White patients, we found a low cumulative incidence of HT in MZL of 2.9% and 4.5% at 5- and 10-year, which was consistent with the Finnish findings (Kalashnikov et al., 2023). At HT, age was associated with OS and there was a high response rate to CHOP-backbone therapies.