Fu, Tommy

Introduction BCL-2 inhibition with venetoclax (ven) was a major advance in CLL treatment, but the 5-week dose ramp-up to mitigate the risk of tumor lysis syndrome and drug-drug interactions (DDIs) challenge treatment optimization. Lisaftoclax is an investigational, oral BCL-2i with a short half-life, allowing it to be ramped-up on a daily schedule. We present updated results of a phase 1b/2 study of lisaftoclax alone or combined with acalabrutinib or rituximab in pts with treatment-naïve (TN; lisaftoclax-acalabrutinib arm), relapsed/refractory, or prior ven-treated CLL/SLL (NCT04215809). Methods Pts were treated with a rapid 4- to 6-day daily ramp-up of lisaftoclax from 20 mg to a target dose of 400, 600, or 800 mg, receiving daily oral lisaftoclax alone or, plus continuous acalabrutinib or 6 cycles of rituximab in 28-day cycles, starting on Cycle 1 Day 8 (C1D8) until disease progression, complete response by C24, or unacceptable toxicity. Intensive blood samples were collected for pharmacokinetic (PK) and exposure-response (E-R) analyses. Results From March 20, 2020, to June 27, 2024, 176 pts were enrolled: 46 in monotherapy and 39 and 91 in rituximab and acalabrutinib combination cohorts, respectively; 154/176 (87.5%) were R/R and 22/176 (12.5%) TN. The median (range) age was 63 (34-80) years; 67% were male; 25.6% had del(17p) and/or TP53 mutation; and 70.6% had unmutated IGHV. Median (range) duration of treatment with lisaftoclax was 16.5 (1-54; monotherapy), 24 (3-39; rituximab), and 27 (1-43; acalabrutinib) months. In R/R pts, the median (range) number of prior lines of therapy was 2 (1-15), and 14 (9%) pts had been treated with ven. Prior ven pts had a median (range) age of 65 (51-78); 79% were male; of evaluable pts, 50% had del(17p), 36% TP53 mut, 64% del(11q), 38% complex karyotype (≥ 3 abnormalities), and 92% unmutated IGHV; 57% were BTKi naïve; and the median (range) number of prior therapies was 3 (1-6). Incidence and severity of TEAEs were similar across cohorts. Common (>10%) any-grade TEAEs in all cohorts combined were neutropenia (59 [33.5%]), diarrhea (38 [21.6%]), anemia (27 [15.3%]), and thrombocytopenia (26 [14.8%]). Grade ≥ 3 TEAEs were neutropenia in 15 (32.6%), 10 (25.6%), and 22 (24%) pts and anemia in 10 (21.7%), 5 (12.8%), and 12 (13.2%) pts in monotherapy, rituximab, and acalabrutinib combination cohorts, respectively. Comprehensive E-R analyses indicated that lisaftoclax had similar systemic exposure as monotherapy or when combined with acalabrutinib or rituximab; lisaftoclax had no DDI when combined with acalabrutinib or rituximab. No discontinuations were attributed to lisaftoclax TRAEs. Forty-four (95.7%) pts in monotherapy discontinued treatment. Most discontinuations were due to progressive disease (n = 41 [23.3%]) and 13 (7.4%), AEs; 9 (5.1%) pts withdrew consent; 7 (4%) achieved complete response or MRD negativity after ≥ 24 cycles; 5 (2.8%) died; and 18 (10.2%) discontinued for other reasons. Clinical (n = 2) and laboratory (n = 3) TLS was observed in 5 (2.8%) pts on lisaftoclax (by Howard/Cairo-Bishop criteria), with cases rapidly resolving to resume lisaftoclax safely. ORR for lisaftoclax plus acalabrutinib in 87 pts was 96.6%, and the median DOR (95% CI, 23-NR) and median PFS (95% CI, 34-NR) were not reached. The 12- and 18-month PFS rates were 89% and 86%, respectively. Fourteen R/R CLL ven-exposed pts received lisaftoclax plus acalabrutinib, of whom 9 had progressed on ven, 3 relapsed after completing ven, and 2 discontinued due to ven intolerance. Median (range) duration of treatment was 16 (3-25) months. Safety profile was similar to that of other study cohorts. ORR was 85.7% (12/14), 100% (8/8), and 66.7% (4/6) in the ven-exposed, ven-exposed but BTKi-naïve, and ven- and BTKi-exposed pts, respectively. The median duration of response (DOR) and progression-free survival (PFS) were not reached. The 12- and 18-month PFS rates were 84% and 73%, respectively. Conclusions Our data suggest that lisaftoclax combined with acalabrutinib is effective for pts with prior ven exposure, including those with progression on ven. In this updated analysis with longer follow-up, no DDIs or new safety findings were observed in TN or R/R CLL/SLL pts treated with lisaftoclax monotherapy/combinations. We continue to accrue pts with prior ven exposure to further evaluate this promising signal. A global registrational phase 3 study GLORA (NCT06104566) is recruiting.

8534 Background: Lenalidomide, an immunomodulatory agent with antitumor and antiproliferative effects, demonstrated rapid and durable efficacy in patients with relapsed/refractory mantle cell lymphoma (MCL) post-bortezomib in the phase II multicenter MCL-001 study. The objective of this analysis was to explore the efficacy of lenalidomide across patient subgroups. Methods: Single-agent lenalidomide was administered at 25 mg/d PO on days 1-21 of a 28-day cycle until disease progression or intolerability; primary endpoints were overall response rate (ORR) and duration of response (DOR) determined by an independent central review committee per modified IWG criteria. Exploratory analyses of ORR and DOR for subgroups were predefined and prospectively conducted. Results: Patients with relapsed/refractory MCL (N=134) had a median age of 67 y, with a median of 4 prior therapies (range, 2-10). The ORR was 28% (7.5% CR/CRu) and DOR was 16.6 months (95% CI, 7.7-26.7). Lenalidomide treatment provided consistent ORR and DOR across all subgroups analyzed by demographics, baseline disease status and prior therapy (Table). High vs normal baseline LDH was the only significant factor by univariate and multivariate logistic regression analysis of ORR (odds ratio=0.193; p=0.002). Conclusions: Single-agent lenalidomide provided consistent clinical benefit in patients with relapsed/refractory MCL post-bortezomib irrespective of patient subgroups at baseline with the exception of LDH. Clinical trial information: NCT00737529. [Table: see text]

8533 Background: Mantle cell lymphoma (MCL) is an aggressive form of non-Hodgkin lymphoma (NHL) with poor prognosis. The immunomodulatory agent lenalidomide shows consistent activity with tolerable safety in multiple phase II studies of relapsed/refractory aggressive NHL (NHL-002 and NHL-003) and MCL post-bortezomib (MCL-001). This pooled analysis further examined the efficacy and safety of single-agent lenalidomide in patients with relapsed/refractory MCL. Methods: Single-agent lenalidomide was given 25 mg/d PO on days 1-21 of 28-day cycles as tolerated for 52 weeks (NHL-002) or until disease progression (NHL-003 and MCL-001). All MCL patients received ≥1 prior treatment, including bortezomib in MCL-001. Efficacy data were examined by independent central review for MCL-001 and NHL-003 and by investigators for NHL-002. Results: 206 patients with relapsed/refractory MCL were studied. The median age was 67 y (range 33-84; 63% ≥65 y), 91% stage III/IV disease and 51% had received ≥4 prior regimens (76% prior bortezomib). Overall response rate (ORR) with lenalidomide was 32% (10% CR/CRu), with a median time to response of 2.1 months and median duration of response (DOR) of 16.6 months (not yet reached in patients with CR/CRu; Table). Kaplan-Meier estimates for median PFS and OS were 5.4 and 23.9 months, respectively. Mean daily dose of lenalidomide was 21 mg. Grade 3/4 AEs included neutropenia (44%), thrombocytopenia (29%), anemia (11%), and fatigue (7%). Other any-grade AEs included tumor flare reaction (7%), venous thromboembolic events (7%), and invasive second primary malignancies (3%). Conclusions: Lenalidomide produced rapid and durable responses in patients with relapsed/refractory MCL, and exhibited a predictable safety profile among 3 phase II studies of lenalidomide in heavily pretreated patients, including prior treatment with bortezomib. Clinical trial information: MCL-001: NCT00737529; NHL-002: NCT00179660; NHL-003: NCT00413036. [Table: see text]

Abstract Introduction Patients with mantle cell lymphoma (MCL) typically respond to initial therapy and almost inevitably relapse with frequent chemoresistance over time and poor outcome. Multiple phase II studies have established the efficacy and safety of lenalidomide, an immunomodulatory agent with tumoricidal and antiproliferative properties, in relapsed/refractory MCL. The prospective phase II multicenter MCL-001 “EMERGE” study led to FDA approval of lenalidomide for patients with relapsed/refractory MCL after 2 prior treatments, that included bortezomib. The activity of lenalidomide was seen regardless of MIPI, number of prior therapies, prior high dose therapy, bulky disease or high tumor burden. One of the most established prognostic factors in MCL is the proliferation index Ki67 (MIB1), now confirmed both in standard and dose-intensive high-dose therapy strategies. We present here longer follow-up of efficacy and safety from the MCL-001 study in patients relapsed/refractory to bortezomib and the potential relationship between Ki-67 and efficacy outcomes. Methods Patients with heavily pretreated MCL, that included prior bortezomib, received lenalidomide 25 mg/day PO, days 1-21 in 28-day cycles until disease progression or intolerability. Primary study endpoints were overall response rate (ORR) and duration of response (DOR); secondary endpoints included complete response (CR), time to response (TTR), progression-free survival (PFS), overall survival (OS), and safety. Response rates and time-to-event data were analyzed by independent central reviewers per modified IWG criteria and Kaplan-Meier estimates respectively (data cut-off March 20, 2013). Ki-67 was examined as an exploratory endpoint by immunohistochemistry for 81/134 patients (60%) either performed on biopsy samples for 24 patients, or based on the Ki-67 scores reported in local pathology reports for 57 patients. Results Median age for the enrolled intent-to-treat patient population (N=134) was 67 years (range, 43-83; 63% ≥65 years). The median number of previous therapies was 4 (range, 2-10; 78% received ≥3), 93% stage III/IV, and 72% were <6 months from last prior treatment. At a median follow-up of 13.2 months, the ORR was 28% (CR/CRu 8%), with a median DOR of 16.6 months (95% CI, 9.2-26.7; median not reached in patients with CR/CRu) by central review. Median TTR was 2.3 months (95% CI, 1.7-13.1), with a median time to CR/CRu of 4.1 months (95% CI, 1.9-13.2). Median PFS was 4.0 months (95% CI, 3.6-6.9), and median OS was 20.9 months (95% CI, 13.7-24.4). The average dose intensity of lenalidomide was 20 mg/day, for a median duration of 94.5 days (range, 1-1,256). Dose reductions or interruptions due to adverse events (AEs) occurred in 40% and 58% of patients, respectively. Neutropenia (44%), thrombocytopenia (28%), and anemia (11%) were the most common treatment-related grade 3/4 AEs. Ki-67 results were available in 81/134 patients, and efficacy data were categorized using 30% and 50% cut-off thresholds for Ki-67 expression (Table 1). Although patient numbers were limited, the ORR was similar in both lower and higher Ki-67 group, but those with lower Ki-67 levels demonstrated better CR rates, DOR and survival outcomes compared with patients with elevated Ki-67. Conclusions Single-agent lenalidomide in heavily pretreated patients with relapsed/refractory MCL post-bortezomib showed durable long-term efficacy with a consistent safety profile. Consistent with what is reported in the literature, high Ki-67 is associated with poor outcome in our cohort with shorter OS. Though based on retrospective evaluation and subsets of patients, the ORR to lenalidomide was similar in both low and high Ki-67 groups, suggesting lenalidomide can be active in patients expressing high levels of Ki67. Prospective studies are needed to confirm these findings. Disclosures: Goy: Celgene: Consultancy, Research Funding, Speakers Bureau. Off Label Use: This is a phase 2 clinical study of safety and efficacy for lenalidomide in patients with MCL. Williams:Celgene: Consultancy, Membership on an entity’s Board of Directors or advisory committees, Research Funding. Drach:Celgene: Honoraria. Ramchandren:Celgene: Research Funding. Zhang:Celgene: Employment. Cicero:Celgene: Employment. Fu:Celgene: Employment. Heise:Celgene: Employment, Equity Ownership. Witzig:Celgene: Research Funding.

Abstract Background: Patients (pts) with DLBCL who receive first-line anthracycline based immunochemotherapy and remain in remission at 2 years have excellent outcomes with overall survival (OS) in one study that was comparable to the age and sex matched general population in cohorts from the US and France (Maurer et al, JCO 2014). To evaluate whether these findings are robust and generalizable, we assessed OS stratified by progression-free survival at 24 months (PFS24) using individual patient data from pts with DLBCL enrolled in 14 multi-center, international randomized clinical trials as part of the SEAL consortium. Methods: Central data alignment was performed by the SEAL statistics and data center. All enrolled patients treated with rituximab-containing anthracycline-based immunochemotherapy as part of initial induction therapy were included in this analysis using an intent-to-treat approach. PFS was defined as time from initiation of first-line therapy to progression or death. PFS24 was defined as being alive and progression-free 24 months (731 days) after initiation of therapy. Overall survival from PFS24 was defined as time from achieving PFS24 until death due to any cause. OS was compared to each patient's age-, sex-, and country- matched general population using expected survival and standardized mortality ratios (SMR). Country-level population rate tables were obtained from www.mortality.org where available. A per-study average rate table was used when country information was unavailable. OS beyond 9 years from treatment initiation was only available the time of analysis from two trials (13% of cohort) and thus follow-up from PFS24 was restricted to the first 7 years after PFS24 for this analysis. Results: Fourteen studies with 7975 patients were included in the SEAL database. 5853 (73%) received rituximab as part of induction therapy and used in this analysis. Median age was 62 years (range 18-92) with 56% >60 years, 54% were male, 57% had elevated LDH, 63% had stage III/IV disease, 13% had ECOG PS 2-4, and IPI was 0-1 in 36%, 2 in 25%, 3 in 23%, and 4-5 in 16%. At a median follow-up of 4.4 years, 1337 (23%) had disease progression, 1489 patients (25%) had died, and 5101 patients were evaluable for PFS24. 1423 (28%) of evaluable patients failed to achieve PFS24. These patients had poor outcomes after progression with median OS of 7.2 months (95% CI 6.8-8.1), 5-year OS of 19%, and SMR of 32.1 (95% CI: 30.0-34.4). Outcome was excellent (median unreached) in the 3678 patients who were progression-free at 24 months, with subsequent OS after achieving PFS24 approaching the age and sex matched general population (Figure). The observed vs. expected OS at 3, 5, and 7 years after achieving PFS24 was 93.1% vs. 94.4%, 87.6% vs. 89.5%, and 80.0% vs. 83.7%, respectively, the SMR was 1.22 (95% CI: 1.09-1.37). In subset analyses examining pts achieving PFS24, adverse prognostic characteristics at baseline (elevated LDH, advanced stage, ECOG PS 2-4, high IPI) were associated with greater decrement in OS from the general population based expected survival (Table). Conclusions: PFS24 from the start of initial therapy stratifies DLBCL pts into populations with distinct outcomes. DLBCL pts treated with rituximab containing anthracycline-based immunotherapy on large randomized clinical trials who are alive without progression at 24 months from start of initial therapy have excellent outcomes with survival that is marginally lower but clinically indistinguishable from the age-, sex-, and country-matched background population for at least 7 years after achieving PFS24. Further follow-up time will be needed to assess any long-term impact of late relapse and survivorship issues in this population. Table Table. Figure Figure. Disclosures Shi: Mayo Clinic: Employment. Cunningham:Amgen: Research Funding; Astra-Zeneca: Research Funding; Bayer: Research Funding; Celgene: Research Funding; Merrimack: Research Funding; Medimmune: Research Funding. Seymour:AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Speakers Bureau; Genentech: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Jaeger:Roche: Honoraria, Research Funding; Celgene: Honoraria, Research Funding. Haioun:Sandoz: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees. Ghesquieres:Mundipharma: Consultancy; Roche France: Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees. Merli:Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Teva Pharmaceuticals Industries: Membership on an entity's Board of Directors or advisory committees. Herbrecht:Servier: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Cell Therapeutics, Inc: Membership on an entity's Board of Directors or advisory committees. Flament:Celgene: Employment, Equity Ownership. Fu:Celgene: Employment, Equity Ownership. Flowers:Gilead: Consultancy, Research Funding; Roche: Consultancy, Research Funding; Acerta: Research Funding; ECOG: Research Funding; Mayo Clinic: Research Funding; Pharmacyclics, LLC, an AbbVie Company: Research Funding; Millenium/Takeda: Research Funding; Infinity: Research Funding; TG Therapeutics: Research Funding; Genentech: Consultancy, Research Funding; NIH: Research Funding; AbbVie: Research Funding. Ou:Mayo Clinic: Employment. Sargent:Celgene: Research Funding. Coiffier:MorphoSys: Consultancy; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy; Celltrion: 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, Research Funding; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees.

Abstract Background OSis the gold standard primary efficacy endpoint for evaluating treatment strategies for DLBCL. Because current standard of care first-line regimens with rituximab plus chemotherapy produce median OS > 8 years, an endpoint assessed earlier would accelerate the evaluation of new therapies and potentially allow patients (pts) to more rapidly benefit from study results. The SEAL group formally evaluated PFS as a surrogate endpoint for OS in first-line therapy for DLBCL. Methods Through a systematic literature search and input from lymphoma experts on the SEAL committee, we identified multicenter, randomized controlled clinical trials that evaluated active treatment and enrolled at least 100 pts with previously untreated DLBCL or aggressive non Hodgkin lymphoma by WHO/REAL classification, published after January 1, 1995. Studies which enrolled only early stage (I or II) pts and studies that could not provide individual pt data (IPD) were excluded from surrogacy analysis. Potential surrogate candidates for OS included: 1) PFS, defined as the time from initiation of induction treatment to progressive disease, relapse or death due to any cause, and 2) PFS rate at 24 months after initiation of induction treatment (PFS24). These endpoints were derived consistently for all studies based on IPD. Surrogacy was evaluated by the correlation between surrogate candidates and OS. Pt-level correlation was measured by the rank correlation coefficient (ρ) and global odds ratio for PFS and PFS24, respectively, estimated by the Copula model. Trial-level correlation was evaluated by the correlation between trial-specific treatment effects on surrogate candidates and OS with two commonly used trial-level R2s: R2WLS (Sargent et al JCO 2005) and R2Copula (Burzykowski et al J R Stat Soc C 2001 and Burzykowski et al J R Stat Soc A 2004). For the R2 measures, a value closer to 1 indicates a stronger correlation. We pre-specified that if either trial-level R2 was >=0.80 and its 95% confidence interval (CI) excluded 0.60, the candidate would meet criteria for surrogacy. Results Thirteen of 14 studies collected to date in the SEAL database met all inclusion criteria. IPD for 7507 pts (median age 63 years, 54% male, 46% ECOG performance status 0, 8% IPI 0, 50% IPI 1-2, 64% stage III/IV, median follow-up time of 52 months) were analyzed. Among 13 studies, one tested maintenance treatment only and two tested both induction and maintenance regimens. One study included four treatment arms. Thus at the trial level, 17 two-arm comparisons were formed: 14 comparisons comparing induction regimens and 3 comparing maintenance; 15 comparisons involved rituximab. Longer PFS was highly correlated with longer OS at the pt level (ρ= 0.85, 95% CI 0.84-0.86), as was PFS24 (Global odds ratio = 61.1, 95% CI 52.6-69.6). The Table shows trial-level correlations, and the Figure shows trial-level association between estimated treatment effects (log(HR) [hazard ratio]) on PFS and OS. The trial-level correlation between PFS and OS was strong and met the pre-specified surrogacy criteria, with R2WLS of 0.83 (95% CI 0.58-0.94) and R2Copula of 0.85 (95% CI 0.72-0.99). Sensitivity analyses including only comparisons including rituximab or only induction regimens showed consistent results. The overall trial-level correlation between PFS24 and OS was reduced slightly, with R2WLS of 0.77 (95% CI 0.49-0.92) and R2Copula of 0.78 (95% CI 0.59-0.96). Performance of PFS24 was improved when restricting analysis to only including induction studies (see table). Conclusion This large IPD pooled-analysis demonstrates that PFS duration met the pre-specified criteria as a robust surrogate endpoint for OS, and can be considered as a surrogate endpoint for OS for frontline DLBCL trials evaluating immunochemotherapy. The earlier endpoint of PFS24 showed promise as a potential surrogate and further validation is warranted. Figure Figure. Disclosures Shi: Mayo Clinic: Employment. Flowers:Millenium/Takeda: Research Funding; TG Therapeutics: Research Funding; Pharmacyclics, LLC, an AbbVie Company: Research Funding; Gilead: Consultancy, Research Funding; NIH: Research Funding; Mayo Clinic: Research Funding; ECOG: Research Funding; Acerta: Research Funding; Infinity: Research Funding; AbbVie: Research Funding; Roche: Consultancy, Research Funding; Genentech: Consultancy, Research Funding. Ou:Mayo Clinic: Employment. Cunningham:Merrimack: Research Funding; Celgene: Research Funding; Bayer: Research Funding; Astra-Zeneca: Research Funding; Amgen: Research Funding; Medimmune: Research Funding. Pfreundschuh:Amgen: 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; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Spectrum: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Seymour:AbbVie Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Genentech: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees. Jaeger:Roche: Honoraria, Research Funding; Celgene: Honoraria, Research Funding. Haioun:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sandoz: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees. Ghesquieres:Mundipharma: Consultancy; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche France: Research Funding. Merli:Teva Pharmaceuticals Industries: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees. Herbrecht:Cell Therapeutics, Inc: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Servier: Membership on an entity's Board of Directors or advisory committees. Flament:Celgene: Employment, Equity Ownership. Fu:Celgene: Employment, Equity Ownership. Coiffier:MorphoSys: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celltrion: 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, Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees. Sargent:Celgene: Research Funding.

Abstract Abstract 905 Introduction: Though dose-intensive strategies using chemoimmunotherapy have significantly improved mantle cell lymphoma (MCL) outcomes with prolonged progression-free survival (PFS), most patients still relapse over time. In the relapsed setting, MCL patients often develop chemoresistance and have a poor overall prognosis. The immunomodulatory agent lenalidomide has demonstrated tumoricidal and antiproliferative effects in MCL and clinical activity and safety in multiple phase II studies in aggressive non-Hodgkin's lymphoma. The objective of the MCL-001 “EMERGE” study was to examine the safety and efficacy of single-agent lenalidomide in subjects with MCL who relapsed or were refractory to bortezomib. Methods: This phase II, multicenter, single-arm, open-label study examined single-agent lenalidomide administered at 25 mg/d PO on days 1–21 of a 28-day cycle until disease progression, unacceptable toxicity, or voluntary withdrawal. The subjects were required to have had prior treatment with rituximab, cyclophosphamide and anthracycline (or mitoxantrone), and to have relapsed or progressed (<12 months) after or were refractory to bortezomib. The primary endpoints were overall response rate (ORR) and duration of response (DOR); secondary endpoints included complete response (CR), PFS, time to progression (TTP), overall survival (OS) and safety. Efficacy data were measured by investigators and an independent central review committee according to modified International Working Group criteria and analyzed by SAS. Results: 134 subjects with relapsed or refractory MCL who were heavily pretreated (no limitation in number of prior therapies) were enrolled. The median age was 67 y (range, 43–83), two-thirds of them being 65 y or older and 93% with advanced stage disease (stage III-IV). The median number of prior therapies was 4 (range, 2– 10) with 78% of subjects having received ≥ 3 prior lines of treatment. The ORR to single-agent lenalidomide was 28% (CR/CRu 8%; Table 1) by independent central review, with a median DOR of 16.6 mo (95% CI, 7.7–26.7; Figure 1). The ORR was 32% (CR/CRu 16%) by investigator assessment, with a median DOR of 18.5 mo. Median time to response (central review) was 2.2 mo (3.7 mo to achieve CR). The median PFS was 4.0 mo (95% CI, 3.6–5.6); median OS was 19.0 mo (95% CI, 12.5–23.9). Subjects received an average dose of 20 mg/d of lenalidomide. Lenalidomide was dose reduced in 38% of subjects; treatment discontinuation due to an adverse event (AE; primarily myelosuppression) was reported in 19% of subjects. The most common grade 3/4 AEs were neutropenia (43%), thrombocytopenia (28%), anemia (11%), pneumonia (8%) and fatigue (7%). Other AEs (any grade) included tumor flare reaction (13 subjects, 10%), deep vein thrombosis (5 subjects, 4%), pulmonary embolism (3 subjects, 2%) and invasive second primary malignancies (3 subjects, 2%). Conclusions: The EMERGE study demonstrated rapid and durable efficacy of lenalidomide in MCL subjects who relapsed or progressed after or were refractory to bortezomib. These results in heavily pretreated MCL subjects (median of 4 prior treatments), and with an expected toxicity profile support single-agent lenalidomide in subjects with relapsed or refractory MCL after bortezomib. Disclosures: Goy: Pfizer: Advisory board member, Advisory board member Other; Seattle Genetics: Advisory board member Other; J&J: Advisory board member, Advisory board member Other; Pharmacyclics: Advisory board member, Advisory board member Other; Millenium: Advisory board member, Advisory board member Other, Speakers Bureau; Celgene: Advisory board member Other. Off Label Use: This is a phase 2 clinical study of safety and efficacy for lenalidomide in patients with MCL. Sinha:Celgene: Research Funding. Williams:Celgene: Clincial Trial Research Support, Advisory Boards, Data Safety Committee Member, Consultant Other, Consultancy. Drach:Celgene: Speakers Bureau; Janssen: Speakers Bureau; Roche: Research Funding. Ramchandren:Seattle Genetics: Speakers Bureau. Herbrecht:Pfizer: Advisory board member Other. Zhang:Celgene: Employment. Cicero:Celgene: Employment. Fu:Celgene: Employment. Witzig:Celgene : Research Funding.

The interaction of death-associated protein kinase 1 (DAPK1) with the 2B subunit (GluN2B) C-terminus of N-methyl-D-aspartate receptor (NMDAR) plays a critical role in the pathophysiology of depression and is considered a potential target for the structure-based discovery of new antidepressants. However, the 3D structures of C-terminus residues 1290–1310 of GluN2B (GluN2B-CT1290-1310) remain elusive and the interaction between GluN2B-CT1290-1310 and DAPK1 is unknown. In this study, the mechanism of interaction between DAPK1 and GluN2B-CT1290-1310 was predicted by computational simulation methods including protein–peptide docking and molecular dynamics (MD) simulation. Based on the equilibrated MD trajectory, the total binding free energy between GluN2B-CT1290-1310 and DAPK1 was computed by the mechanics generalized born surface area (MM/GBSA) approach. The simulation results showed that hydrophobic, van der Waals, and electrostatic interactions are responsible for the binding of GluN2B-CT1290–1310/DAPK1. Moreover, through per-residue free energy decomposition and in silico alanine scanning analysis, hotspot residues between GluN2B-CT1290-1310 and DAPK1 interface were identified. In conclusion, this work predicted the binding mode and quantitatively characterized the protein–peptide interface, which will aid in the discovery of novel drugs targeting the GluN2B-CT1290-1310 and DAPK1 interface.

Background: The human Monoamine Transporters (hMATs), primarily including hSERT, hNET and hDAT, are important targets for the treatment of depression and other behavioral disorders with more than the availability of 30 approved drugs. Objective: This paper is to review the recent progress in the binding mode and inhibitory mechanism of hMATs inhibitors with the central or allosteric binding sites, for the benefit of future hMATs inhibitor design and discovery. The Structure-Activity Relationship (SAR) and the selectivity for hit/lead compounds to hMATs that are evaluated by in vitro and in vivo experiments will be highlighted. Methods: PubMed and Web of Science databases were searched for protein-ligand interaction, novel inhibitors design and synthesis studies related to hMATs. Results: Literature data indicate that since the first crystal structure determinations of the homologous bacterial Leucine Transporter (LeuT) complexed with clomipramine, a sizable database of over 100 experimental structures or computational models has been accumulated that now defines a substantial degree of structural variability hMATs-ligands recognition. In the meanwhile, a number of novel hMATs inhibitors have been discovered by medicinal chemistry with significant help from computational models. Conclusion: The reported new compounds act on hMATs as well as the structures of the transporters complexed with diverse ligands by either experiment or computational modeling have shed light on the poly-pharmacology, multimodal and allosteric regulation of the drugs to transporters. All of the studies will greatly promote the Structure-Based Drug Design (SBDD) of structurally novel scaffolds with high activity and selectivity for hMATs.