Abstract: Background In a recent phase-III trial CPX-351 (Jazz Pharmaceuticals, Palo Alto, CA), a liposomal encapsulation of cytarabine and daunorubicin, has shown higher remission rates and longer overall survival (OS) in patients aged 60 to 75 years with AML with myelodysplasia-related changes (AML-MRC) or therapy-related AML (t-AML) in comparison to conventional 7+3 regimen. Based on this CPX-351 has been approved in the USA 2017 and in Europe 2018 for adult patients with newly-diagnosed AML-MRC or t-AML. Still, several issues such as age ( & lt;60 years), measurable residual disease (MRD), molecular subgroups and outcome after allo-HCT were not addressed in the phase-III trial. Aiming to investigate these open aspects and to provide more clinical experience with CPX-351, we performed a real-world analysis of patients with AML treated with CPX-351 as first-line therapy. Design/Methods: For this retrospective analysis, we collected data on baseline characteristics, treatment details including allo-HCT and outcome from patients with newly-diagnosed AML-MRC or t-AML, who were treated with CPX-351 according to the EMA label between 2018 and 2020 in 25 German centers participating in the Study Alliance Leukemia (SAL), German Cooperative Transplant Study Group and the AML Study Group (AMLSG). Results: A total of 188 patients (median age 65 years, range 26 to 80) with t-AML (29%) or AML-MRC (70%) including 46 patients (24%) & lt;60 years could be analyzed. Eigthy-six percent received one, 14% two induction cycles and 10% received consolidation with CPX-351. Following induction, CR/CRi rate was 47% including 64% of patients with available information achieving measurable residual disease (MRD) negativity ( & lt;10-3) as measured by flow cytometry at local laboratories. Additionally, 35 patients were categorized as MLFS at first remission control, which achieved CRi (n=16) or CR (n=10) in the further course without additional therapy. After median follow-up of 9.3 months, median overall survival (OS) was 21 months and 1-year OS rate was 64%. In multivariate analysis, complex karyotype predicted lower response (p=.0001), and pretreatment with hypomethylating agents (p=.02) and adverse European LeukemiaNet 2017 genetic risk (p & lt;.0001) were associated with lower OS. Allo-HCT was performed in 116 patients (62%) including 101 of these patients with CR prior transplant and resulted in 1-year OS of 73% (median survival not reached), especially in MRD negative patients (p=.048). With 69% of patients developing grade III/IV non-hematologic toxicity following induction and a day 30-mortality of 8% the safety profile was consistent with previous findings. Conclusion: The results from this real-world analysis confirm CPX-351 as an efficient treatment for these high-risk AML patients bridging to facilitating allo-HCT in many patients with encouraging outcome after transplantation. Disclosures Röllig: AbbVie: Honoraria, Research Funding; Amgen: Honoraria; Bristol-Meyer-Squibb: Honoraria, Research Funding; Janssen: Honoraria; Jazz: Honoraria; Novartis: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Roche: Honoraria, Research Funding. Stelljes: Pfizer: Consultancy, Research Funding, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Medac: Speakers Bureau; Celgene/BMS: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; MSD: Consultancy, Speakers Bureau; Kite/Gilead: Consultancy, Speakers Bureau. Gaidzik: Janssen: Speakers Bureau; Pfizer: Speakers Bureau; Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Unglaub: Novartis: Consultancy, Other: travel costs/ conference fee; JazzPharma: Consultancy, Other: travel costs/ conference fee. Thol: Abbvie: Honoraria; Astellas: Honoraria; BMS/Celgene: Honoraria, Research Funding; Jazz: Honoraria; Novartis: Honoraria; Pfizer: Honoraria. Krause: Siemens: Research Funding; Takeda: Honoraria; Pfizer: Honoraria; art-tempi: Honoraria; Kosmas: Honoraria; Gilead: Other: travel support; Abbvie: Other: travel support. Haenel: Celgene: Consultancy, Honoraria; Amgen: Consultancy; Novartis: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Bayer Vital: Honoraria; Jazz: Consultancy, Honoraria; GSK: Consultancy. Vucinic: Novartis: Honoraria; Janssen: Honoraria, Other: Travel Sponsoring; Abbvie: Honoraria, Other: Travel Sponsoring; Gilead: Honoraria, Other: Travel Sponsoring; MSD: Honoraria. Fransecky: Novartis: Honoraria; Medac: Honoraria; Abbvie: Honoraria, Research Funding; Amgen: Honoraria; Takeda: Honoraria. Holtick: Celgene: Honoraria; Sanofi: Honoraria. Kobbe: Celgene: Research Funding. Holderried: Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; GSK: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Speakers Bureau; Gilead Sciences: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; MSD: Speakers Bureau; Daiichi Sankyo: Other: travel support; Jazz Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Therakos: Other: Travel support; Janssen: Other: Travel support; Abbvie: Other: Travel support; Eurocept Pharmaceuticals: Other: Travel support; Medac: Other: Travel support. Heuser: Astellas: Research Funding; Bayer AG: Honoraria, Research Funding; BMS/Celgene: Research Funding; Jazz Pharmaceuticals: Honoraria, Research Funding; BergenBio: Research Funding; Daichi Sankyo: Honoraria, Research Funding; Karyopharm: Research Funding; Novartis: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Roche: Research Funding; Tolremo: Honoraria; AbbVie: Honoraria; Janssen: Honoraria. Sauer: Pfizer: Consultancy, Speakers Bureau; Abbvie: Consultancy, Speakers Bureau; Matterhorn Biosciences AG: Consultancy, Other: DSMB/SAB Member; Takeda: Consultancy, Other: DSMB/SAB Member. Goetze: Abbvie: Other: Advisory Board; BMS/Celgene: Other: Advisory Board, Research Funding. Döhner: Jazz Roche: Consultancy, Honoraria; Agios and Astex: Research Funding; Astellas: Research Funding; Abbvie: Consultancy, Honoraria; Janssen: Honoraria, Other: Advisory Board; Daiichi Sankyo: Honoraria, Other: Advisory Board; Novartis: Consultancy, Honoraria, Research Funding; Celgene/BMS: Consultancy, Honoraria, Research Funding. Döhner: Jazz Pharmaceuticals: Honoraria, Research Funding; Agios: Honoraria, Research Funding; Pfizer: Research Funding; Bristol Myers Squibb: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Gilead: Honoraria; Janssen: Honoraria; Helsinn: Honoraria; GEMoaB: Honoraria; Amgen: Honoraria, Research Funding; Astellas: Honoraria, Research Funding; Astex Pharmaceuticals: Honoraria; AstraZeneca: Honoraria; Berlin-Chemie: Honoraria; Oxford Biomedica: Honoraria; Roche: Honoraria. Schliemann: Philogen S.p.A.: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Other: travel grants; Astellas: Consultancy; AstraZeneca: Consultancy; Boehringer-Ingelheim: Research Funding; BMS: Consultancy, Other: travel grants; Jazz Pharmaceuticals: Consultancy, Research Funding; Novartis: Consultancy; Roche: Consultancy; Pfizer: Consultancy. Schetelig: Roche: Honoraria, Other: lecture fees; Novartis: Honoraria, Other: lecture fees; BMS: Honoraria, Other: lecture fees; Abbvie: Honoraria, Other: lecture fees; AstraZeneca: Honoraria, Other: lecture fees; Gilead: Honoraria, Other: lecture fees; Janssen: Honoraria, Other: lecture fees . Germing: Novartis: Honoraria, Research Funding; Janssen: Honoraria; Bristol-Myers Squibb: Honoraria, Other: advisory activity, Research Funding; Celgene: Honoraria; Jazz Pharmaceuticals: Honoraria. Schroeder: JAZZ: Honoraria, Research Funding.

Abstract: In the past decade outcome of adult ALL was improved significantly using pediatric-based chemotherapy in combination with risk-adapted stem cell transplantation (SCT) and targeted therapies. The GMALL Trial 08/2013 (NCT02881086) for patients (pts) aged 18-55 years (yrs) with newly diagnosed ALL/LBL has a BFM-based 2-phase induction, up to 8 cycles of PEG-asparaginase (ASP) with up to 7 cycles of HDMTX, HDAC, a reinduction phase and conventional maintenance up to 2.5 yrs. Two cycles Nelarabine are implemented for standard risk (SR) T-ALL. Pts with B-precursor-ALL (B-ALL) receive Rituximab independent of CD20 expression (Ph+ only if CD20+). Ph+ ALL pts receive Imatinib and a dose reduced induction (Vincristine, Dexamethasone, ASP). ASP is scheduled in induction 1 (IP1) (d 20) and 2 (d 34 for Ph+ and d 44 for Ph-) and dose is adapted to risk factors for hepatotoxicity. Pts with BMI & gt;30 and/or liver steatosis receive 500 U/m 2, whereas 2000 U/m 2 is the standard dose. It is recommended to withhold the 2 nd dose of ASP in case of clinically relevant ASP-associated toxicities. Pts with high-risk (HR) features (WBC & gt; 30,000/µl in B-ALL, pro B-ALL-, KMT2A rearrangement, early/mature T-ALL) or Ph+ ALL are considered for SCT in CR1 after 1 st consolidation (C1). Pts with MolFail (table 1) after C1 are candidates for targeted therapy (Blinatumomab, Nelarabin) followed by SCT. Randomization (R) I evaluates CNS irradiation versus i.th. prophylaxis in B- ALL/LBL. R II compares SCT versus SR therapy in HR pts with MolCR after induction. Both randomizations are blinded and not available for analysis. The trial is ongoing and scheduled to recruit 950 pts. Between 8/2017-4/2021 770 pts from 78 centers were included and 705 were evaluable. The median age was 35 (18-55) yrs, 638 had ALL (B,Ph-: 55%, Ph+: 20%, T: 25%,) and 67 pts LBL (B:12%; T:88%). For ALL the hematologic (Hem) CR rate after C1 was 93% and the MolCR Rate 61% (75% mol. response) (table 1). HemCR rate was 72% in LBL with 21% PR. PET CT was negative in half of the LBL PR cases. The lowest HemCR rate was observed in early T-ALL (83%) together with a MolCR rate of 45% (71% mol. response). In Ph- pts 2000 U/m 2 as first dose ASP was administered in 66%, 500 U/m 2 in 24%, no ASP in 1% and other doses in 9%. In pts with Ph+ ALL the respective numbers were 61%, 21%, 6% and 13%. For the 2nd dose the numbers were 43%, 21%,13% and 22% for Ph- and 41%, 24%, 13% and 22% for Ph+ pts. Bilirubine increases grade III/IV were observed in Ph- ALL in 18% of the cases treated with 500 U/m 2 vs 24% for 2000 U/m 2. In Ph+ ALL the respective numbers were 5% vs 3%. GOT/GPT grade III/IV increases were observed 29% of Ph- ALL pts treated with 500 U/m 2 vs 25% of those with 2000 U/m 2. The respective numbers for Ph+ ALL were 24% and 40%. At a median follow-up of 23 mo, the overall survival (OS) for all pts (N=705) was 88% and 76% at 1 and 3 yrs resp (subgroups see table 1). OS was correlated to age, 87%, 74%, 69% and 73% at 3 yrs for pts aged 18-25, 26-35, 36-45 and 46-55 yrs resp. SR T-ALL reached an OS of 86% at 3 yrs with a conventional and nelarabine based consolidation. 79% of pts with an indication for SCT were transplanted (64 sibling, 174 MUD). The OS of SCT pts after SCT was 75% at 3 yrs. 63 pts with MolFail became candidates for a targeted therapy, which was realized in 89% of the cases. The molecular response was evaluable in 51 pts and reached 55% (N=40) and 18% (N=11) after one cycle of Blinatumomab or Nelarabin resp. Pts with MolFail (N=63) achieved an OS of 84% at 1y and 72% at 3 years resp (71% for Ph- and 76% for Ph+). This large, ongoing prospective multicenter trial provides promising preliminary results. This applies also to those aged 45-55 yrs underlining that adult pts beyond the variable AYA definitions can benefit from pediatric-based therapy. Intensive and individualized ASP therapy was feasible. Whereas high HemCR rates were observed in nearly all subgroups, MolCR rates ranged from 41-74% and a relevant proportion remained MRD low positive underlining the need for detailed MRD classification. MRD-based targeted treatment was realized in a high proportion of pts. Responses to Blinatumomab in MolFail were lower compared to previous trials. Responses to Nelarabine in MolFail T-ALL pts were only 18%. OS of MolFail pts however was promising with the combination of targeted therapy and SCT. Thus, SCT is still a key component, contributing to improved outcomes although the overall proportion of SCT was lower than in previous GMALL trials. Funded by Deutsche Krebshilfe Figure 1 Figure 1. Disclosures Goekbuget: Servier: Consultancy, Other; Morphosys: Consultancy; Astra Zeneca: Other: Invited talk for company sponsored symposia (with honor); Amgen: Consultancy, Other: Invited talks for company sponsored symposia (with honoraria); Research funding for institution; Novartis: Consultancy, Other: Research funding for Institution; Pfizer: Consultancy, Other: Research funding for institution; Jazz Pharmaceuticals: Other: Research funding for institution; Incyte: Other: Research funding for Institution; Cellestia: Consultancy; Erytech: Consultancy; Abbvie: Other; Gilead/Kite: Consultancy. Stelljes: Pfizer: Consultancy, Research Funding, Speakers Bureau; Medac: Speakers Bureau; Amgen: Consultancy, Speakers Bureau; MSD: Consultancy, Speakers Bureau; Celgene/BMS: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Kite/Gilead: Consultancy, Speakers Bureau. Viardot: Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; University Hospital of Ulm: Current Employment; F. Hoffmann-La Roche Ltd: Honoraria, Membership on an entity's Board of Directors or advisory committees; Kite/Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees. Nachtkamp: Jazz: Honoraria; Bsh medical: Honoraria; Celgene: Other: Travel Support. Topp: Novartis: Consultancy; Roche: Consultancy, Research Funding; Kite, a Gilead Company: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Janssen: Consultancy; Amgen: Consultancy, Research Funding; Macrogeniecs: Research Funding; Regeneron: Consultancy, Research Funding; Gilead: Research Funding; Universitatklinikum Wurzburg: Current Employment. Wäsch: Sanofi: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Pfizer: Consultancy; Takeda: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Novartis: Consultancy; BMS/Celgene: Consultancy; Gilead: Consultancy. Vucinic: Abbvie: Honoraria, Other: Travel Sponsoring; MSD: Honoraria; Janssen: Honoraria, Other: Travel Sponsoring; Gilead: Honoraria, Other: Travel Sponsoring; Novartis: Honoraria. Baldus: Novartis: Honoraria; Amgen: Honoraria; Celgene/BMS: Honoraria; Jazz: Honoraria. Brüggemann: Amgen: Other: Advisory Board, Travel support, Research Funding, Speakers Bureau; Incyte: Other: Advisory Board; Janssen: Speakers Bureau. Pfeifer: Incyte: Honoraria, Research Funding. Schwartz: Amgen: Membership on an entity's Board of Directors or advisory committees, Other: Travel grants, Speakers Bureau; Novartis: Speakers Bureau; Jazz Pharmaceuticals: Other: Travel grants, Speakers Bureau; BTG International Inc: Membership on an entity's Board of Directors or advisory committees; MSD Sharp & Dohme: Membership on an entity's Board of Directors or advisory committees; Basilea: Other: Travel grants; Gilead: Other: Travel grants, Speakers Bureau; Pfizer: Honoraria, Speakers Bureau; Morphosys: Research Funding. Fiedler: Abbvie: Consultancy, Honoraria, Other: Meeting attendance, Preparation of information material; Amgen: Consultancy, Honoraria, Other: Meeting attendance, Preparation of information material, Patents & Royalties, Research Funding; Ariad/Incyte: Honoraria; Celgene: Consultancy, Honoraria; Jazz: Consultancy, Honoraria, Other: Meeting attendance, Preparation of information material; MorphoSys: Consultancy, Honoraria; Novartis: Honoraria; Pfizer: Consultancy, Honoraria, Research Funding; Daiichi Sanyko: Consultancy, Other: Meeting attendance, Preparation of information material; Stemline: Consultancy; Servier: Consultancy, Other: Meeting attendance, Preparation of information material. OffLabel Disclosure: Nelarabine in newly diagnosed T-ALL

Abstract: Introduction: Acute lymphoblastic leukemia (ALL) represents approx. 5% of all newly diagnosed leukemias in patients between 55 and 70 years of age. Despite recent advances especially in younger patients, the prognosis of elderly patients with ALL remains dismal, even after moderately intensive chemotherapy. Incorporation of antibody-based therapies in the first line induction therapy bears the potential of a significant increased response rate and survival with the reduction of treatment toxicity. Methods: This open label phase II study of the German Multicenter Study Group on Adult Acute Lymphoblastic Leukemia was conducted at 13 centers. Patients aged & gt;55 years with newly diagnosed Ph/BCR-ABL negative acute B-precursor ALL were eligible. Leukemic blasts had CD22 surface expression of at least 20%. The 1st induction cycle consisted of InO 0.8mg/m2 on day1 and 0.5mg/m2 on d8 and d15 together with dexamethasone 10 mg/m2 (day7-8, day14-17) and one intrathecal injection (i.th.) of methotrexate (MTX), cytarabine (AraC) and dexamethasone (Dex). The 2nd and 3rd induction cycle consisted of InO 0.5mg/m2 on day 1, 8 and 15 plus i.th. MTX/AraC/Dex. Patients achieving a complete remission (CR) were offered to receive 5 conventional consolidation therapies (3 x ID-MTX/asparaginase; 2 x ID-AraC) and one reinduction therapy (idarubicine/ AraC/ cyclophosphamide / Dex.) in combination with rituximab (for CD20+ ALL), followed by a maintenance therapy with 6-MP/MTX. The primary endpoint was event free survival (EFS) at 12-months follow-up. An event was defined as any of the following: persisting bone marrow blasts after 2 cycles of InO, relapse or death. An event rate of ≤40% at 12 months follow-up was considered to qualify the experimental treatment as very promising for additional testing. Under the assumption of one-sided type I error of 5% and 80% power, 42 evaluable patients were needed for primary endpoint analysis (registered with ClinicalTrials.gov, identifier: NCT03460522). Results: As of July 2021, 45 patients were included, with induction results available for 43 patients. Two patients were excluded per protocol from further analysis, as they received only one induction: 1 prolonged toxicity (CR after induction), 1 withdrawn consent. Median age at initial diagnosis was 64 years (range 56-80 years). 38 patients were diagnosed with a common- and 5 with a pro-B ALL. Median CD22 expression on leukemic blasts was 69% (range 21-99%). Due to suspected therapy related liver toxicities, a single patient received only 2 induction cycles (complete remission after 1st induction). All other patients completed 3 cycles of induction therapy and achieved complete remission (CR/CRi), mainly after the 1st induction. Results of minimal residual disease (MRD), measured by real-time quantitative PCR, are available for all 43 patients, with 23/43 (53%) and 31/42 (74%) patients being MRD negative after 2nd and 3rd induction therapy, respectively. Four patients with MRD failure (≥10 -4) after the 3rd induction therapy are still in CR (2 were treated with conventional chemotherapy per this protocol, one proceeded to allogeneic stem cell transplantation (aSCT), one received blinatumomab). MRD below the threshold of 10 -4 was detected in 15 patients after the 2nd induction (no relapse occurred so far). 8 of these 15 patients were MRD negative after the 3rd induction. So far, 7 events have been reported (during year 1: 3 deaths in CR and 1 relapsed ALL; during year 2: 1 death in CR and 2 patients with relapse). With a median follow-up of 422 days, the probability of OS at 1 and 2 years is 91% (95% C.I. 80-100%) and 77% (95% C.I. 57-96%), respectively. 4 patients received an aSCT in 1st CR, 1 patient in 2nd CR. Regarding adverse events (AEs) during induction cycles 1, 2 and 3, most common AEs ≥CTC grade 3 reported were leukocytopenia (in 60%, 12% and 3% of all cases, respectively), anemia (28%, 2%, 0%), thrombocytopenia (35%, 7%, 3%) and elevation of liver enzymes (14%, 5%, 0%). So far, one patient has been reported with suspected veno occlusive disease (after 2nd induction therapy). Conclusion: Three cycles of InO as induction therapy for the treatment of elderly patients with acute B-cell ALL results in very high remission rates with MRD-response in up to 90% (MRD negativity or MRD-levels & lt;10 -4). The promising EFS and survival rates of these patients warrant further investigation of this novel induction therapy in a prospective randomized trial. Figure 1 Figure 1. Disclosures Stelljes: Pfizer: Consultancy, Research Funding, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Medac: Speakers Bureau; MSD: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Celgene/BMS: Consultancy, Speakers Bureau; Kite/Gilead: Consultancy, Speakers Bureau. Wäsch: Sanofi: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Pfizer: Consultancy; Takeda: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Novartis: Consultancy; BMS/Celgene: Consultancy; Gilead: Consultancy. Nachtkamp: Jazz: Honoraria; Bsh medical: Honoraria; Celgene: Other: Travel Support. Haenel: Jazz: Consultancy, Honoraria; GSK: Consultancy; Bayer Vital: Honoraria; Takeda: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Amgen: Consultancy; Celgene: Consultancy, Honoraria. Berdel: Philogen S.p.A.: Consultancy, Current equity holder in publicly-traded company, Honoraria, Membership on an entity's Board of Directors or advisory committees. Goekbuget: Amgen: Consultancy, Other: Invited talks for company sponsored symposia (with honoraria); Research funding for institution; Astra Zeneca: Other: Invited talk for company sponsored symposia (with honor); Erytech: Consultancy; Cellestia: Consultancy; Incyte: Other: Research funding for Institution; Jazz Pharmaceuticals: Other: Research funding for institution; Novartis: Consultancy, Other: Research funding for Institution; Gilead/Kite: Consultancy; Morphosys: Consultancy; Pfizer: Consultancy, Other: Research funding for institution; Servier: Consultancy, Other; Abbvie: Other. OffLabel Disclosure: Inotuzumab Ozogamicin

Abstract: Background In newly diagnosed acute myeloid leukemia (AML) with FLT3 mutations (FLT3-mut), the tyrosine kinase inhibitor midostaurin (MIDO) in combination with intensive chemotherapy (IC) is considered standard of care (SoC). Subgroup analyses from the ALFA 0701 trial indicate that the addition of the conjugated CD33 antibody gemtuzumab ozogamicin (GO) to IC increases efficacy in the FLT3-ITD subgroup of patients (pts), providing a rationale for the combined use of MIDO plus GO with IC in newly diagnosed FLT3-mut AML. On the other hand, there is evidence that the subgroup of core-binding factor (CBF) AML benefits from the inhibition of the tyrosine kinase KIT with respect to survival end points. In this respect, MIDO is a more powerful KIT inhibitor as compared to dasatinib which has been applied in previous studies. While the combination of IC plus GO in induction treatment is considered SoC in patients with CBF AML the addition of MIDO to SoC seems promising to further improve treatment outcomes in the CBF subgroup. We therefore set up the clinical trial MOSAIC composed of a phase-I part to prospectively assess the feasibility of combining MIDO plus GO with IC (MODULE), followed by a randomized phase-II part evaluating the benefit of adding GO to SoC in FLT3-mut AML (MAGMA) and of adding MIDO to SoC in CBF AML (MAGNOLIA). Here, we report the results of the phase-I part (MODULE). Methods MODULE is a dose escalation phase-I trial following a 3+3 design. Eligibility criteria include newly diagnosed AML harboring either FLT3 or CBF mutations, and fitness for IC. Standard 7+3 IC using cytarabine 200 mg/m 2 continuous infusion over 7 days plus daunorubicin 60 mg/m 2 on 3 days was combined with increasing doses of MIDO and GO in three dose levels: 1 st dose level (GO 3 mg/m 2 i.v. QD on day 1+4 plus 25 mg MIDO p.o. BID days 8-21); 2 nd dose level (GO 3 mg/m 2 i.v. QD on day 1+4 plus 50 mg MIDO p.o. BID days 8-21); 3 rd dose level (GO 3 mg/m 2 i.v. QD on day 1+4+7 plus 50 mg MIDO p.o. BID days 8-21). Based on the 3+3 design, each dose cohort consisted of three but maximal six pts. The protocol predefined the maximal tolerable dose (MTD) as reached if ≤2 dose-limiting toxicity events (DLTs) would occur in maximum six evaluable pts who received ≥80% of the planned study therapy. Results From September 2020 to July 2021, 11 pts were enrolled. In the 1 st dose level, three pts completed the regular study period without DLT, whereas treatment had to be discontinued in one patient on day 6 before commencement of MIDO due to infusion related reaction CTC grade 4. This patient was subsequently replaced. In the 2 nd dose level, one of three enrolled pts experienced neutropenic colitis CTC grade 3 on day 14 of treatment, which was classified as DLT. The colitis fully recovered by day 27 after commencement of treatment. As a result of the DLT, the dose cohort was subsequently extended by three additional pts. Of those, one patient developed signs of sinusoidal obstruction syndrome (SOS) CTC grade 3 starting on day 13 of treatment. SOS was classified as DLT. The patient was treated with defibrotide and supportive care until recovery on day 28. Another patient had to discontinue treatment on day 14 due to inability of swallowing MIDO. This patient was replaced as the target dose of MIDO was not reached. As predefined in the study protocol, the occurrence of 2 DLTs in six evaluable pts precluded further dose escalation to the 3 rd dose level and defined the 2 nd dose level as safe and feasible. A total number of 5 serious adverse events (SAEs) were observed among all 11 pts who completed the DLT evaluation period: infusion related reaction, colitis, parvo-B19 infection, prolonged neutropenia CTC grade 4, and SOS. An unexpected increase in frequency of common AML adverse events was not observed. The 30-day mortality among all enrolled pts was 0%. After blood count recovery, remission assessment showed complete remission (CR) in 7 pts, CR with incomplete hematologic/platelet recovery (CRi/CRp) in 3 pts and primary refractory disease in one patient. Conclusion GO standard dose on days 1 + 4 and MIDO standard dose on days 8-21 of induction treatment is defined as MTD which can be safely combined with standard IC in newly diagnosed AML. In the phase-I cohort of the MOSAIC trial, CR/CRi/CRp rates of 91% were reached. Based on the results of this dose finding trial the MTD of combined MIDO and GO will be defined as phase-II dose for the randomized phase-II studies in CBF and FLT-mut AML. Figure 1 Figure 1. Disclosures Röllig: Jazz: Honoraria; Amgen: Honoraria; Bristol-Meyer-Squibb: Honoraria, Research Funding; Janssen: Honoraria; Pfizer: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; AbbVie: Honoraria, Research Funding; Roche: Honoraria, Research Funding. Schliemann: Philogen S.p.A.: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Other: travel grants; Astellas: Consultancy; AstraZeneca: Consultancy; Boehringer-Ingelheim: Research Funding; BMS: Consultancy, Other: travel grants; Jazz Pharmaceuticals: Consultancy, Research Funding; Novartis: Consultancy; Roche: Consultancy; Pfizer: Consultancy. Fransecky: Novartis: Honoraria; Abbvie: Honoraria, Research Funding; Amgen: Honoraria; Takeda: Honoraria; Medac: Honoraria. Baldus: Novartis: Honoraria; Amgen: Honoraria; Celgene/BMS: Honoraria; Jazz: Honoraria. Wermke: Novartis, Roche, Pfizer, BMS: Consultancy, Honoraria, Research Funding.

Abstract: To investigate the efficacy and toxicities of CPX-351 outside a clinical trial, we analyzed 188 patients (median age 65 years, range 26–80) treated for therapy-related acute myeloid leukemia (t-AML, 29%) or AML with myelodysplasia-related changes (AML-MRC, 70%). Eighty-six percent received one, 14% two induction cycles, and 10% received consolidation (representing 22% of patients with CR/CRi) with CPX-351. Following induction, CR/CRi rate was 47% including 64% of patients with available information achieving measurable residual disease (MRD) negativity ( 〈 10 −3 ) as measured by flow cytometry. After a median follow-up of 9.3 months, median overall survival (OS) was 21 months and 1-year OS rate 64%. In multivariate analysis, complex karyotype predicted lower response ( p  = 0.0001), while pretreatment with hypomethylating agents ( p  = 0.02) and adverse European LeukemiaNet 2017 genetic risk ( p   〈  0.0001) were associated with lower OS. Allogeneic hematopoietic cell transplantation (allo-HCT) was performed in 116 patients (62%) resulting in promising outcome (median survival not reached, 1-year OS 73%), especially in MRD-negative patients ( p  = 0.048). With 69% of patients developing grade III/IV non-hematologic toxicity following induction and a day 30-mortality of 8% the safety profile was consistent with previous findings. These real-world data confirm CPX-351 as efficient treatment for these high-risk AML patients facilitating allo-HCT in many patients with promising outcome after transplantation.

Abstract: Background Double induction using two subsequent 7+3 regimens of cytarabine plus anthracycline is commonly performed in AML patients with an adequate performance status in order to maximize dose intensity upfront. However, for patients with a good early response at day 15 of first induction, there is no prospective randomized evidence on the necessity or value of a second induction cycle. Aims In order to answer the question if good responders of the first 7+3 induction could be spared a second induction cycle, we set up randomized-controlled SAL DaunoDouble trial. The study prospectively assesses the outcome of patients with a good early response with respect to the number of induction cycles (single versus double). We assumed non-inferiority of single induction in terms of complete remission (CR/CRi) rate, based on a margin of 7.5%. Here, we present the results of the planned interim analysis. Methods Patients (pts) 18-65 years with newly diagnosed AML, normal cardiac and organ function received a first induction cycle with seven days of cytarabine plus three days of daunorubicin ("7+3"). Response assessment in bone marrow was done on day 15 after the initiation of chemotherapy and confirmed by central review. A blast count & lt;5% was defined as good response. Pts with good response were randomized to receive a second induction cycle (arm D) or no second induction cycle (arm S). Primary endpoint was CR/CRi after completion of induction, secondary endpoints were RFS, and OS. Results Between 2014 and 2020, 624 evaluable pts were enrolled and received the first induction cycle with 7+3. A marrow blast clearance below 5% on day 15 was achieved in 298 pts (48%), providing eligibility for randomization. Of these patients, 150 were randomized into arm S and 148 into arm D, respectively. Median age was 52 years, 92% had de novo AML, NPM1 mutation was present in 53%, FLT3-ITD in 25% of pts. Favorable, intermediate and adverse risk (ELN 2017) were present in 56%, 34% and 10% of pts, respectively. CR/CRi rates at the end of induction were 86% after single induction and 85% after double induction. The CR/CRi rates in 224 pre-defined per-protocol pts were 88% versus 91%, resulting in a CR difference of 3% (95%-CI -0.047-0.111; p for non-inferiority test 0.145). After a median follow-up time of 24 months, RFS was slightly but not significantly lower after single induction with a 3-year RFS of 53% versus 64% (HR 1.4, p=0.125), whereas no differences were seen in 3-year OS, with a of rate of 74% versus 75% (HR 1.1, p=0.645) after single versus double induction. Conclusion The interim analysis results show that in good responders, the difference between CR rates after single versus double induction was even smaller than the predefined 7.5% margin, suggesting a trend for non-inferiority of single induction, although statistical significance was not reached. The trial continued recruitment. These findings suggest that in good responders, it may be safe to omit a second induction cycle if a second cycle poses a high risk. Figure. CR + CRi, RFS and OS after randomization to single versus double induction. Disclosures Alakel: Pfizer: Consultancy. Jost:Pfizer: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; JAZZ: Other: travel support; Celgene: Other: travel support. Novak:Roche: Consultancy; Janssen: Other: Travel expenses; Takeda: Consultancy; Amgen: Consultancy, Other: Travel expenses; Pfizer: Consultancy; Novartis: Consultancy. Krause:Takeda: Honoraria; Celgene: Other: Travel Support; MSD: Honoraria; Pfizer: Honoraria; Siemens: Research Funding; Gilead: Other: Travel Support. Held:Roche: Consultancy, Other: Travel, Accommodations, Expenses, Research Funding; BMS: Consultancy, Other: Travel, Accommodations, Expenses, Research Funding; MSD: Consultancy; Acrotech: Research Funding; Spectrum: Research Funding; Amgen: Research Funding. Platzbecker:AbbVie: Consultancy, Honoraria; Amgen: Honoraria, Research Funding; Geron: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria. Thiede:AgenDix GmbH: Other: Co-owner and CEO. Müller-Tidow:Daiichi Sankyo: Research Funding; Pfizer: Research Funding, Speakers Bureau; BiolineRx: Research Funding; Janssen-Cilag GmbH: Speakers Bureau.