Corradini, Paolo

Abstract Checkpoint inhibitors (CPIs) have shown remarkable efficacy in Hodgkin lymphoma (HL), and are now used routinely. While allogeneic hematopoietic cell transplantation (allo-HCT) remains a curative option for HL, there are concerns prior CPIs may exacerbate post–allo-HCT complications, particularly graft-versus-host disease (GVHD), and lead to worse outcomes. Given the relative paucity of data, we performed a Center for International Blood and Marrow Transplant Research/European Society for Blood and Marrow Transplantation study to examine the impact of prior CPIs in allo-HCT. We included 2186 adult patients aged >18 years who received a first allo-HCT using a matched related, unrelated, or haploidentical donor from 2008 to 2023. Twenty-seven percent of patients received prior CPIs. GVHD prophylaxis was posttransplant cyclophosphamide (PTCy) in 55.8% of patients in the CPI cohort, and 35% in the non-CPI cohort. Median follow-up among survivors was longer for the non-CPI (39 months) than CPI cohort (16.5 months). In multivariate analysis, prior CPI exposure did not affect overall survival (OS) or nonrelapse mortality, but resulted in improved progression-free survival (non-CPI vs CPI hazard ratio [HR], 0.81; 0.67-0.98; P = .03) and lower relapse incidence (HR, 0.58; 0.45-0.76; P < 001). While grade 2 to 4 (HR, 1.26; 1.04-1.53; P = .02) and 3 to 4 (HR, 1.41; 1.04-1.92; P = .03) acute GVHD (aGVHD) were increased, differences in chronic GVHD (cGVHD) were not significant. PTCy–based GVHD prophylaxis resulted in improved OS, lower grade 2 to 4 aGVHD, and cGVHD in patients with prior CPI exposure. In summary, allo-HCT should still be considered a curative option for patients with HL in the era of CPIs.

Background: Proven salvage therapies for pts with triple-class refractory MM who progress on BCMA-targeted therapies are lacking.Fc receptor-homolog 5 (FcRH5) is a type I membrane protein that is expressed exclusively in the B-cell lineage. Cevostamab is a FcRH5xCD3 BsAb that facilitates T cell-mediated killing of MM cells. In an initial Phase I study (GO39775), cevostamab monotherapy was clinically active and had manageable toxicity in pts with heavily pretreated relapsed/refractory MM (Trudel et al. ASH 2021). In Cohort A1 of the subsequent Phase I/II CAMMA 2 study (CO43476; NCT05535244), cevostamab was highly active and had manageable safety at the 160mg target-dose (TD) level in pts with triple-class refractory MM who had received a prior BCMA-targeted antibody-drug conjugate (ADC; overall response rate [ORR]: 60%, 6/10 pts) or chimeric antigen receptor T-cell (CAR-T) therapy (ORR: 73%, 8/11 pts) but had not received a prior BCMA-targeted BsAb (Kumar et al. EHA 2024). We present initial results from Cohort A2, which enrolled pts with triple-class refractory MM who had received prior BCMA-targeted therapies, including ≥1 BCMA-targeted BsAb. An exploratory analysis of baseline patient and tumor-related factors is also presented. Methods: Cevostamab was initiated with step dosing (Cycle [C] 1 Day [D] 1: 0.3mg; C1D2, D3, or D4 depending on the emergence of cytokine release syndrome [CRS] after the initial administration: 3.3mg) and continued at the 160mg TD on C1D8 and on D1 of each subsequent 21-day cycle until disease progression (PD) or unacceptable toxicity. Cytokine, tumor antigen, T-cell function/activation, and inhibitory immune checkpoint expression were assessed in blood and tumor samples collected at baseline and during treatment. Results: As of February 23, 2024, 21 pts (median age: 64 years, range: 46-84) had been enrolled into Cohort A2. Seven pts (33%) had extramedullary disease and 5/12 pts (42%) with a conclusive assay result had high-risk cytogenetics (t(4;14), t(14;16), or del(17p)). All pts were heavily pretreated (median prior lines of therapy: 8, range: 5-14); 62% had received ≥2 prior BCMA-targeted therapies (median time since last: 122 days, range: 68-558) and 33% had received ≥2 prior BsAbs (median time since last: 139 days, range: 68-782). Most pts (86%) were refractory to their last line of therapy; 62% were penta-drug refractory. Median follow-up was 173 days (range: 20-360). Grade (Gr) 3-4 adverse events (AEs) occurred in 71% of pts (15/21). Gr 3-4 AEs in >3 pts were neutropenia, anemia, thrombocytopenia (38% each), and infections (29%). CRS occurred in 76% of pts (16/21) and was mainly Gr 1 (43%) or Gr 2 (29%); 1 patient had Gr 3 CRS. One treatment-related Gr 5 (fatal) AE of pneumonia was reported in the context of PD. No treatment-related AEs leading to cevostamab discontinuation occurred. Objective responses (partial response [PR] or better) were observed in 2/21 pts (ORR: 10%). Both pts achieved a very good PR and had ongoing responses at cut-off. Stable disease was observed in 10 pts (48%). Pts in the prior BsAb group had received more prior lines of therapy than those in the prior ADC and CAR-T groups (median 8 vs 5 and 6, respectively) and more prior BCMA-targeted therapies (median 2 vs 1 and 1). The percentage of pts with low levels (<4.5 ng/mL) of soluble BCMA in plasma was also higher in the prior BsAb group (47% vs 0% and 18%). At baseline, inhibitory immune checkpoint expression across T-cell subsets was more common in the prior BsAb group. Notably, the median frequency of PD1+CD8+Tnaive and TIGIT+CD8+Tnaive cells in blood was higher in the prior BsAb group (21% and 29%, respectively) than in the prior ADC (3% and 6%) and CAR-T groups (4% each). Peak median IL-6 and IFN-γ levels were delayed until the first TD in the prior BsAb group, suggesting a different pharmacodynamic profile. Conclusions: Cevostamab has manageable safety in pts with triple-class refractory MM who have received prior BCMA-targeted therapies, including ≥1 BCMA-targeted BsAb. Clinical responses were less frequent in the prior BsAb group than in the prior ADC and CAR-T groups, which could be explained by the higher number of prior lines of therapy and T-cell exhaustion due to multiple prior exposures to BsAbs. Notably, the high frequency of CD8+ T-cell subsets expressing inhibitory immune checkpoints in the prior BsAb group suggests a level of T-cell dysfunction that could prevent effective T-cell activation.

TPS8064 Background: Multiple myeloma (MM) remains an incurable disease. Combinations of established agents, including proteasome inhibitors (PIs), immunomodulatory drugs (IMiDs), and anti-CD38 antibodies, are used in all lines of therapy, but re-exposure to previously received classes of therapy is associated with decreasing response rates and duration of response (Moreau et al. 2021). BCMA-targeted agents have recently been approved for the treatment of patients with RRMM whose disease has been exposed or become refractory to PIs, IMIDs and anti-CD38 antibodies (triple-class exposed or refractory MM). Although effective, the majority of patients who respond to anti-BCMA agents eventually relapse. Proven salvage therapies for these patients are currently lacking and represent a new unmet medical need. Cevostamab is an immunoglobulin G1-based T-cell-engaging bispecific antibody that targets Fc receptor-homolog 5 (FcRH5) on myeloma cells and CD3 on T cells. Dual binding results in T-cell activation and potent killing of MM cells. In an ongoing Phase I study (GO39775; NCT03275103), cevostamab monotherapy showed promising activity in heavily pre-treated patients with RRMM, including those with prior exposure to anti-BCMA agents (Trudel et al. 2021). Methods: CAMMA 2 (CO43476; NCT05535244) is an open-label, multicenter Phase I/II trial evaluating cevostamab monotherapy in patients with RRMM who are triple-class refractory and have previously received an anti-BCMA agent. Prior anti-BCMA antibody-drug conjugates or chimeric antigen receptor (CAR) T cells are permitted in Cohorts A1 and B1, while prior anti-BCMA bispecific antibodies are allowed in Cohorts A2 and B2. In A1 and A2, cevostamab is administered by intravenous infusion and is initiated with step dosing (0.3mg on Cycle [C] 1 Day [D] 1 and 3.3mg on C1D2, D3, or D4 depending on the emergence and resolution of cytokine release syndrome [CRS] after the initial administration), with the target dose of 160mg given on C1D8 and on D1 of each subsequent 21-day cycle. Patients are hospitalized for the C1 administrations only and treatment is continued until disease progression or unacceptable toxicity occurs. CRS is managed per protocol based on the clinical presentation and may involve corticosteroid and tocilizumab treatment. Primary objectives are evaluation of efficacy (primary endpoint: objective response rate by investigator assessment using IMWG criteria) and safety. Secondary objectives include assessment of quality of life, pharmacokinetics, pharmacodynamics, and immunogenicity. Cohorts B1 and B2 will evaluate the efficacy and safety of cevostamab at the recommended Phase II dose in this setting. As of February 2023, enrolment into Cohorts A1 and A2 is ongoing. Clinical trial information: NCT05535244 .

AbstractThe multicenter, phase Ib CC‐122‐DLBCL‐001 dose‐expansion study (NCT02031419) explored the cereblon E3 ligase modulator (CELMoD) agent avadomide (CC‐122) plus rituximab in patients with relapsed/refractory (R/R) diffuse large B‐cell lymphoma (DLBCL) or follicular lymphoma (FL). Patients received avadomide 3 mg/day 5 days on/2 days off plus rituximab 375 mg/m2 on day 8 of cycle 1, day 1 of cycles 2 through 6, and day 1 of every third subsequent cycle for 2 years. Primary endpoints were safety and tolerability; preliminary efficacy was a secondary endpoint. A total of 68 patients were enrolled (DLBCL [n = 27], FL [n = 41; 31 lenalidomide‐naïve, 10 lenalidomide‐treated]). Median age was 62 years (range, 33–84 years), and patients had received a median of 3 (range, 1–8) prior regimens. Among patients with DLBCL, 66.7% had primary refractory disease (partial response or less to initial therapy). Among patients with FL, 65.9% were rituximab‐refractory at study entry and 10.0% were lenalidomide‐refractory. The most common any‐grade avadomide‐related adverse events (AEs) were neutropenia (63.2%), infections/infestations (23.5%), fatigue (22.1%), and diarrhea (19.1%). The most common grade 3/4 avadomide‐related AEs were neutropenia (55.9%) infections/infestations (8.8%), and febrile neutropenia (7.4%). In patients with DLBCL, overall response rate (ORR) was 40.7% and median duration of response (mDOR) was 8.0 months. In patients with FL, ORR was 80.5% and mDOR was 27.6 months; response rates were similar in lenalidomide‐naïve and ‐treated patients. Avadomide plus rituximab was well tolerated, and preliminary antitumor activity was observed in patients with R/R DLBCL and FL, including subgroups with typically poor outcomes. These results support further investigation of novel CELMoD agents in combination with rituximab in R/R DLBCL and FL.

Abstract Mature T-cell lymphomas constitute the most common indication for allogeneic hematopoietic cell transplantation (allo-HCT) of all lymphomas. Large studies evaluating contemporary outcomes of allo-HCT in mature T-cell lymphomas relative to commonly used donor sources are not available. Included in this registry study were adult patients who had undergone allo-HCT for anaplastic large cell lymphoma, angioimmunoblastic T-cell lymphoma (AITL), or peripheral T-cell lymphoma not otherwise specified (PTCL-NOS) between 2008 and 2018. Hematopoietic cell transplantation (HCT) platforms compared were posttransplant cyclophosphamide-based haploidentical (haplo-)HCT, matched sibling donor (MSD) HCT, matched unrelated donor HCT with in vivo T-cell depletion (MUD TCD+), and matched unrelated donor HCT without in vivo T-cell depletion (MUD TCD−). Coprimary end points were overall survival (OS) and progression-free survival (PFS); secondary end points included nonrelapse mortality (NRM), and relapse/progression incidence (RI). A total of 1942 patients were eligible (237 haplo-HCT; 911 MSD; 468 MUD TCD+; 326 MUD TCD−). Cohorts were comparable for baseline characteristics with the exception of higher proportions of patients with decreased performance status (PS) and marrow graft recipients in the haplo-HCT group. Using univariate and multivariate comparisons, OS, PFS, RI, and NRM were not significantly different among the haplo-HCT, MSD, MUD TCD+, and MUD TCD− cohorts, with 3-year OS and PFS of 60%, 63%, 59%, and 64%, respectively, and 50%, 50%, 48%, and 52%, respectively. Significant predictors of inferior OS and PFS on multivariate analysis were active disease status at HCT and decreased PS. AITL was associated with significantly reduced relapse risk and better PFS compared with PTCL-NOS. Allo-HCT can provide durable PFS in patients with mature T-cell lymphoma (TCL). Outcomes of haplo-HCT were comparable to those of matched donor allo-HCT.

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 > 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 Introduction:The prognosis is poor for patients with follicular lymphoma (FL) who experience early relapse within 2 years of initial diagnosis and for those who are double refractory to both rituximab and chemotherapy (Casulo et al. J Clin Oncol 2015). Avadomide, a cereblon-modulating agent that promotes degradation of the hematopoietic transcription factors Aiolos and Ikaros, is being examined in this setting. Avadomide demonstrated promising clinical activity in combination with obinutuzumab or rituximab in relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) and FL (Michot et al. Blood 2017; Ribrag et al. Blood 2017). Herein, we report FL subgroup analyses for the avadomide plus rituximab combination (Arm D) of the CC-122 DLBCL-001 study in both lenalidomide-naïve and treated patients. Methods: CC-122-DLBCL-001 (NCT02031419) is aphase Ib dose escalation/expansion study of avadomide, CC-223, and CC-292 given orally as doublets, and as triplets in combination with rituximab, as well as avadomide plus rituximab doublets, in patients with R/R DLBCL or FL after ≥1 prior line of therapy. In the dose expansion phase of the study, patients received avadomide once daily (QD) for 5 days/week (5/7 d), with a fixed dose of intravenous rituximab 375 mg/m2/cycle (28-day cycle). The study endpoints were safety, tolerability, pharmacokinetics, preliminary efficacy (overall response rate [ORR] and complete response [CR]), and blood pharmacodynamic markers of avadomide. Results: As of May 1, 2018, 37 patients with FL were enrolled in the Arm D expansion group, including 29 in cohort 1 (no prior lenalidomide) and 8 in cohort 2 (≥2 cycles of prior lenalidomide). Baseline patient characteristics were similar between the two cohorts. In the total FL population, the median age was 61 years (range, 41-81 years), 54% were male, and 46% had an Eastern Cooperative Oncology Group performance status of 1. The median number of prior systemic anticancer regimens was 3 (range, 1-8). At disease diagnosis, three patients (8%) had bulky disease (≥7 cm in single dimension) and 7 (19%) had high Follicular Lymphoma International Prognostic Index scores. Twenty-three patients (62%) were refractory to rituximab and 11 (30%) were double-refractory to rituximab and an alkylating agent. As of the data cutoff, 27 patients (71%) were ongoing and no evaluable patients had experienced a dose-limiting toxicity. The most common (≥10%) any-grade adverse events (AEs) were neutropenia (46%) and anemia (24%). Grade 3/4 AEs occurring in >1 patient were neutropenia (32%); fatigue, dizziness, and anemia (8% each); febrile neutropenia and diarrhea (5% each). Six patients (16%) experienced serious AEs related to study drugs. One patient died during the study (sepsis considered possibly related to study treatment). Avadomide dose reduction occurred in 7 (19%) patients. Among all FL patients, the ORR was 65% with 8 patients (22%) achieving a CR. Response rates appeared to be independent of prior lenalidomide treatment, with an ORR of 62% (CR=14%) in cohort 1 and an ORR of 75% (CR=50%) in cohort 2. The median follow up for progression-free survival (PFS) was 6.3 months and 49% of patients had <6 months of PFS follow up. In the total FL population, 6-month and 12-month PFS rates were 83 (95% CI, 64-93) and 66 (37-84), respectively. Conclusions: Avadomide combined with rituximab was well tolerated. AEs were generally consistent with the known safety profile of avadomide and toxicities associated with rituximab. Moreover, this combination showed promising efficacy in patients with R/R FL independent of prior treatment with lenalidomide. These findings support the role of avadomide plus an anti-CD20 antibody as a novel chemotherapy-free treatment for this difficult to treat patient population. Disclosures Nastoupil: TG Therappeutics: Research Funding; Karus: Research Funding; Novartis: Honoraria; Merck: Honoraria, Research Funding; Juno: Honoraria; Celgene: Honoraria, Research Funding; Gilead: Honoraria; Janssen: Research Funding; Spectrum: Honoraria; Genentech: Honoraria, Research Funding. Ribrag:Amgen: Research Funding; Roche: Honoraria, Other: travel; epizyme: Consultancy, Honoraria; MSD: Honoraria; Infinity: Consultancy, Honoraria; NanoString Technologies: Consultancy, Honoraria; BMS: Consultancy, Honoraria, Other: travel; Servier: Consultancy, Honoraria; pharmamar: Other: travel; Gilead: Consultancy, Honoraria; Incyte Corporation: Consultancy; argenX: Research Funding. Chavez:Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Humanigen: Consultancy; Merck: Research Funding; Kite: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Speakers Bureau. Witzig:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Andorsky:AstraZeneca: Consultancy; Genentech: Consultancy; Celgene: Research Funding; CTI BioPharma: Consultancy, Research Funding. Corradini:Janssen: Honoraria, Other: Lecturer; Amgen: Honoraria, Other: Advisory Board & Lecturer; Gilead: Honoraria, Other: Advisory Board & Lecturer; Celgene: Honoraria, Other: Advisory Board & Lecturer; Roche: Honoraria, Other: Advisory Board & Lecturer; Takeda: Honoraria, Other: Advisory Board & Lecturer; Sanofi: Honoraria, Other: Advisory Board & Lecturer; Novartis: Honoraria, Other: Advisory Board & Lecturer; Abbvie: Honoraria, Other: Advisory Board & Lecturer; Sandoz: Other: Advisory Board. Flinn:ArQule: Research Funding; Agios: Research Funding; TG Therapeutics: Research Funding; Calithera: Research Funding; BeiGene: Research Funding; Verastem: Consultancy, Research Funding; Janssen: Research Funding; Curis: Research Funding; Pharmacyclics: Research Funding; Incyte: Research Funding; Trillium: Research Funding; Forty Seven: Research Funding; Kite: Research Funding; Pfizer: Research Funding; Verastem: Research Funding; Novartis: Research Funding; Genentech: Research Funding; Merck: Research Funding; Portola: Research Funding; Takeda: Research Funding; Seattle Genetics: Research Funding; Constellation: Research Funding; Forma: Research Funding; Celgene: Research Funding; Gilead: Research Funding; Infinity: Research Funding. Sangha:Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees; Lilly: Honoraria, Membership on an entity's Board of Directors or advisory committees; Lundbeck: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche/Genentech: Honoraria, Membership on an entity's Board of Directors or advisory committees; Astra Zeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees; BI: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees. Uttamsingh:Celgene Corporation: Employment, Equity Ownership. Hagner:Celgene Corporation: Employment, Equity Ownership. Gandhi:Celgene Corporation: Employment, Equity Ownership. Chen:Celgene Corporation: Employment, Equity Ownership. Hege:Mersana: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; SITC: Membership on an entity's Board of Directors or advisory committees; Celgene Corporation: Employment, Equity Ownership, Patents & Royalties: multiple; Arcus Biosicences: Membership on an entity's Board of Directors or advisory committees. Pourdehnad:Celgene Corporation: Employment, Equity Ownership. Kuruvilla:Celgene: Honoraria; Roche: Consultancy, Honoraria, Research Funding; Gilead: Consultancy, Honoraria; Lundbeck: Honoraria; BMS: Consultancy, Honoraria; Abbvie: Consultancy; Merck: Consultancy, Honoraria; Amgen: Honoraria; Seattle Genetics: Consultancy, Honoraria; Karyopharm: Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Princess Margaret Cancer Foundation: Research Funding; Leukemia and Lymphoma Society Canada: Research Funding.

Abstract Abstract 2877 Poster Board II-853 Background and Objective: In newly diagnosed multiple myeloma (MM) patients, treatment with lenalidomide plus high-dose dexamethasone (RD) was superior to high-dose dexamethasone in terms of both response rates and 1-year progression-free survival (PFS) (Zonder JA et al, Blood 2007;110:77). Preliminary results suggest that the combination lenalidomide plus low-dose dexamethasone (Rd) compared to the RD regimen yields significantly better 2-year overall survival (OS) (Rajkumar SV et al, J Clin Oncol 2008;26:8504). The combination of melphalan, prednisone, and lenalidomide (MPR) has been investigated in a phase I/II study showing promising results (Palumbo A et al, J Clin Oncol 2007; 25:4459-4465). The goal of this case –control study was to compare the efficacy and the toxicity of the lenalidomide/dexamethasone (len/dex) combination vs MPR as primary therapy for newly diagnosed elderly MM patients, to determine the additive value of melphalan compared to a regimen of lenalidomide plus corticosteroid. Patients and methods: Data from 51 newly diagnosed MM patients enrolled in Italy in a phase I/II dose-escalating trial, from January to October 2005, with MPR, were analyzed. For comparison of their outcome, 37 patients were identified among newly diagnosed patients seen at the Mayo Clinic from March 2005 to December 2008 who received len/dex as primary therapy and were enrolled in phase II or III trials. Patients treated with MPR received 9 monthly cycles of oral melphalan (doses ranging from 0.18 to 0.25 mg/kg on days 1-4), prednisone (2 mg/kg on days 1-4) and lenalidomide (doses ranging from 5 to 10 mg/day on days 1-21). After 9 cycles, patients started maintenance with lenalidomide alone (10 mg, days 1-21) until relapse or progression. Patients treated with len/dex received oral lenalidomide (25 mg/day, days 1-21) plus dexamethasone, either at low-dose (n=17) (40 mg orally days 1, 8, 15, 22) or at high-dose (n=21) (40 mg orally on days 1-4, 9-12, and 17-20). Treatment was continued until progression, relapse or unacceptable toxicity, or could be stopped at the physician's discretion. Patients (n=13) were allowed to receive transplant if they wished and were deemed eligible. Outcome was analyzed on an intention-to-treat basis. The Chi-square or the rank sum tests were used to compare variables. Time-to-event analysis was performed using the Kaplan-Meier method and comparisons were determined by the log-rank test and the Cox proportional hazards model. Results: On intention-to-treat analysis, 15.7% versus 23.7% patients, respectively in the MPR and in the len/dex group, (p=0.342) achieved a complete response, and 43.2% vs 47.4%, (p=0.691) achieved at least a very good partial response. Time-to-progression (TTP) (median: 24.7 vs 27.5 in MPR and len/dex groups, respectively; HR 1.04; 95% CI 0.55-1.98; p=0.903), PFS (median: 24.7 vs 27.5 in MPR and len/dex groups, respectively; HR 1.03; 95% CI 0.55-1.92; p=0.926) and OS (2-year OS: 86.2% in MPR group vs 89.1% in len/dex, HR 0.86; 95% CI 0.38-1.98; p=0.730) were not significantly different between the 2 groups. No significant differences in TTP, PFS and OS were reported when MPR patients were compared with the subgroup of patients treated with low-dose dexamethasone plus lenalidomide. Similar results were found when the analysis was restricted to MPR patients and len/dex pair mates receiving lenalidomide plus low/dose dexamethasone, matched according to age and sex, and who did not received transplant. The toxicity profile was different in the two groups. Hematologic grade 3-4 toxicities were more common with MPR compared with len/dex, in particular neutropenia (66.7% vs 21.1%, p < 0.001) and thrombocytopenia (31.4% vs 2.6%, p < 0.001), respectively. Grade 3-4 gastrointestinal events (13.2% vs 2.0%, p= 0.080), thrombotic events (13.2 vs 5.9, p= 0.279) and fatigue (10.5% vs 3.9%, p= 0.395) were more common with len/dex compared with MPR. Conclusion: Results of this case-control study show that both MPR and Rd are efficacious regimens for elderly MM patients. Data need however to be carefully evaluated and randomized control trials are needed to confirm these results. Disclosures: Off Label Use: research drug in combination to standard of care. Kumar:celgene: Research Funding; millenium: Research Funding; bayer: Research Funding; novartis: Research Funding; genzyme: Research Funding. Dispenzieri:celgene: Research Funding. Gertz:celgene: Honoraria; genzyme: Honoraria; millenium: Honoraria; amgen: Honoraria. Lacy:celgene: Research Funding. Musto:celgene: Honoraria. Fonseca:medtronic: Consultancy; genzyme: Consultancy; celgene: Consultancy; amgen: Consultancy; BMS: Consultancy; otsuka: Consultancy. Petrucci:celgene: Honoraria; Janssen Cilag: Honoraria. Greipp:celgene: Research Funding. Boccadoro:jansen Cilag: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; pharmion: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Palumbo:Janssen-Cilag: Honoraria; Celgene: Honoraria.

Background:Patients (pts) with multiple myeloma associated with high cytogenetic risk abnormalities have poor outcomes. In CASTOR, D‐Vd prolonged progression‐free survival (PFS) vs bortezomib and dexamethasone (Vd) alone, and exhibited a manageable safety profile in pts with RRMM. We conducted a subgroup analysis of D‐Vd vs Vd in CASTOR, based on cytogenetic risk.Aims:The purpose of this analysis was to determine the efficacy and safety of D‐Vd in CASTOR based on cytogenetic risk status.Methods:Eligible pts received ≥1 prior line of therapy. Cytogenetic risk was based on a combined analysis of next‐generation sequencing (NGS) and fluorescence in situ hybridization (FISH)/karyotype testing. High‐risk pts had t(4;14), t(14;16), or del17p abnormalities. Standard (std)‐risk pts were confirmed negative for all 3 abnormalities. Minimal residual disease (MRD; 10–5) was assessed via NGS using clonoSEQ® assay V2.0.Results:In CASTOR (D‐Vd, n = 251; Vd, n = 247), high‐risk was confirmed in 26.7% and 25.9% of pts in the D‐Vd and Vd groups, respectively. At a median follow up of 40.0 months (mo), D‐Vd prolonged PFS vs Vd in pts with high‐ (median 13.4 vs 7.2 mo; HR, 0.40 [95% CI, 0.24–0.65]; P = 0.0002) or std‐risk (median 18.4 vs 6.8 mo; HR, 0.28 [95% CI, 0.20–0.37]; P <0.0001). Higher ORR was seen with D‐Vd vs Vd (high risk: 84.8% vs 60.0%; P = 0.0226; std risk: 85.4% vs 65.0%; P <0.0001), including deep responses of ≥CR (high risk: 33.3% vs 8.3%; std risk: 29.9% vs 10.2%) and ≥VGPR (high risk: 65.2% vs 35.0%; P = 0.0049; std risk: 64.3% vs 28.0%; P <0.0001). Higher rates of MRD negativity (high risk: 17.9% vs 0%; P = 0.0003; std risk: 13.3% vs 2.4%; P = 0.0003), and sustained MRD negativity for ≥6 mo (high risk: 16.4% vs 0%; P = 0.0006; std risk: 6.1% vs 1.8%; P = 0.0859) and ≥12 mo (high risk: 7.5% vs 0%; P = 0.0581; std risk: 1.8% vs 0%; P = 0.2477) were seen with D‐Vd vs Vd. D‐Vd significantly prolonged PFS vs Vd in pts with one prior line of therapy only (high risk: median 20.1 vs 8.4 mo; HR, 0.30 [95% CI, 0.14–0.64]; P = 0.0012; std risk: median 32.6 vs 7.9 mo; HR, 0.18 [95% CI, 0.11–0.29]; P <0.0001; Figure). Additionally, D‐Vd significantly prolonged PFS2 (high risk: median 27.9 vs 18.6 mo; HR, 0.59 [95% CI, 0.37–0.94]; P = 0.0258; std risk: median 40.1 vs 21.6 mo; HR, 0.43 [95% CI, 0.32–0.59]; P <0.0001) regardless of cytogenetic risk status.Additional data including safety analyses will be presented.Summary/Conclusion:Adding daratumumab to Vd demonstrates significant efficacy in pts with high‐risk RRMM including PFS2. Among high‐risk RRMM pts, MRD negativity was only achieved with D‐Vd. These findings support use of D‐Vd for high‐risk RRMM. NCT02136134image