Schreeder, Marshall T.

8017 Background: LAM-002 is a selective inhibitor of PIKfyve that disrupts lysosomal homeostasis, inducing cytotoxicity in B-cell lymphoma models as monotherapy or with anti-CD20 or anti-PDL1 antibodies (Gayle et al., Blood 2017;129(13):1768). Methods: In this study, patients received LAM-002 orally 2-3 times per day (BID or TID) in a 3+3 escalation. Additional patients received LAM-002 125 mg BID as monotherapy; with rituximab 375 mg/m2 intravenously (IV) and or subcutaneously weekly (Q1W) x 4 → Q8W x 4; or atezolizumab 1200 mg IV Q3W until disease progression or unacceptable toxicity. Pharmacokinetics (PK) were assessed for 8 hours postdose on Days 1 and 8. Efficacy was evaluated Q6-12W. Results: The study enrolled 62 patients (M:F n = 32/30); median [range] age = 69 [46-89] years; with diagnoses (n) of diffuse large B-cell lymphoma (25), follicular lymphoma (19), marginal zone lymphoma (8), mantle cell lymphoma (5), or chronic lymphocytic leukemia (5) to receive LAM-002 alone (n) at 50 mg BID (3), 100 mg BID (8), 150 mg BID (8), 75 mg TID (4), or 125 mg BID (20); LAM-002/rituximab (12); or LAM-002/atezolizumab (7). During LAM-002 dose-ranging (50 mg BID → 100 mg BID → 150 mg BID → 75 mg TID → 125 mg BID) transient, reversible nausea and/or diarrhea occurred at 150 mg BID and 75 mg TID, resulting in a LAM-002 recommended Phase 2 dosing regimen (RP2DR) of 125 mg BID. Among 39 patients receiving LAM-002, 125 mg BID, alone or in combination for up to 22 cycles (1.9 years), adverse events were typically low-grade. LAM-002 PK showed rapid absorption, dose proportionality, minimal accumulation, and no substantive changes with rituximab or atezolizumab coadministration. In patients with follicular lymphoma and median [range] prior therapies = 3 [1-9] treated with the RP2DR, objective response rates were 2/7 (29%; 1 complete response [CR], 1 partial response [PR]) with LAM-002, 5/8 (63%; 1 CR, 4 PRs) with LAM-002/rituximab, and 2/2 (100%; 2 PRs) with LAM-002/atezolizumab. Conclusions: LAM-002, the first clinical PIKfyve inhibitor, is safe alone or with full-dose anti-CD20 or anti-PD-L1 inhibition. LAM-002 does not cause the myelosuppressive or immune adverse events associated with lenalidomide or PI3K inhibitors. Promising efficacy supports registration-directed Phase 2/3 testing of LAM-002 monotherapy and combination therapy for patients with previously treated follicular lymphoma. Clinical trial information: NCT02594384 .

8032 Background: Btk supports activation, survival, and proliferation of malignant B cells in CLL and B-NHL. AVL-292 is an oral, potent (IC50 < 0.5nM), selective small molecule covalent inhibitor of Btk. Methods: Patients (pts) with previously treated CLL or B-NHL were administered AVL-292 in escalating cohorts of 125, 250, or 400 mg po QD using a 3+3 design in continuous 28 day cycles until progressive disease (PD) or toxicity. Key objectives were safety, DLT, MTD, PK, and Btk occupancy. Plasma AVL-292 levels were assessed by LC-MS-MS. Btk occupancy by AVL-292 was assessed by covalent probe assay in peripheral blood mononuclear cells. Results: 12 pts have enrolled (3 each at 125 and 250 mg and 6 at 400 mg: 5M/7F; median age 68 years, range 45-79; median 2.5 prior therapies, range 1-10) including 8 CLL (2 with 17p-, 2 with 11q22-, 2 with both 17p-/11q22-; 2 mutated IGHV, 5 unmutated IGHV, 1 missing) and 4 B-NHL (1 diffuse large B cell lymphoma (DLBCL); 1 follicular (FL); 2 marginal zone (MZL)). Median time on treatment is 65 days, range 28-158. Ten of 12 pts continue on treatment: 1 pt (DLBCL) discontinued for PD after 1 cycle and 1 pt (FL) for DLT (Gr 4 plts; 400 mg QD). No other DLTs or grade 4 adverse events (AEs) have occurred and MTD has not been reached. Most frequent AEs reported include transient diarrhea, rash/skin infection, URI, nausea, and fatigue. Gr 3 AEs include 1 atrial fibrillation (not drug related) and 1 ANC low (probably drug related). To date, 8 of 8 CLL patients have stable disease (SD) with median 28% decrease from baseline lymph node measurement (range 3-40% decrease). Six of 8 pts with CLL experienced increased ALC in cycle 1: median increase 89.5% (range 50-212%). Two of 4 NHL pts have SD (both MZL), 1 PD (DLBCL), and 1 not evaluable due to DLT (FL). Full Btk occupancy was achieved with dose levels ≥ 250 mg. Multiple dose PK exposure (AUClast) was linear with no accumulation from Day 1 to 15. Conclusions: AVL-292 was well tolerated from 125-400 mg po QD and early efficacy analysis in CLL and B-NHL shows 10/11 efficacy evaluable pts with SD. Full Btk occupancy was achieved with ≥ 250 mg QD and PK was predictable with no accumulation. Dose escalation is ongoing and MTD cohort expansion is planned.

Abstract Introduction CC-292, an oral, highly selective, small-molecule irreversible-inhibitor of Btk is under investigation for the treatment of CLL and other B-cell malignancies. This phase 1 trial investigated the safety, dose limiting toxicities (DLT), and clinical activity of CC-292 monotherapy in subjects with relapsed or refractory (R/R) CLL or non-Hodgkin's lymphoma. This interim analysis focused on the safety and clinical activity in subjects with CLL and small cell lymphocytic leukemia (SLL). Methods Eligible subjects with R/R (≥ 1 prior therapy) CLL/SLL were treated with monotherapy CC-292 in a dose-escalation study with doses ranging from 125 mg to 1000 mg QD and BID dose levels of 375 mg and 500 mg. As a maximum tolerated dose was not established, CLL patients have been enrolled in an early dose expansion cohort of 750 mg QD and preliminary recommended phase 2 dose expansion cohort at 500 mg BID. All subjects received continuous dosing in 28-day cycles until progressive disease or intolerable toxicity. Clinical activity was investigator assessed per the 2008 iwCLL criteria. Results 83 subjects with R/R CLL/SLL have been enrolled as of June 30, 2013. Baseline characteristics include median age of 67 years (34-89), 52% Rai stage 3/4 disease, median 3 prior therapies (1-12), and 34% refractory to last treatment. Poor-risk factors were present in 67% of subjects, including del11q (22%), del17p (24%), and unmutated IgVH (54%). 67% of subjects remain on study. Subjects have received a median of 6 treatment cycles (0.2-21.6). The most frequent grade 3/4 adverse events (AEs) included neutropenia (21%), thrombocytopenia (15%), pneumonia (10%), and anemia (8%). Rates of febrile neutropenia were low (4%). The most common treatment-emergent AEs (≥ 10% of subjects) were diarrhea (59.7%), fatigue (37.5%), neutropenia (26.4%), thrombocytopenia (26.4%), nausea (26.4%), pyrexia (22.2%), headache (19.4%), cough (19.4%), upper respiratory infection (16.7%), peripheral edema (15.3%), abdominal pain (15.3%), dizziness (13.9%), muscle spasms (13.9%), contusion (13.9%), anemia (12.5%), pneumonia (12.5%), sinusitis (12.5%), and urinary tract infection (11.1%). One CLL patient at the 500 mg BID dose level has experienced a drug-related adverse event of grade 4 thrombocytopenia during Cycle 1 that was assessed as a DLT. The number of patients discontinuing study treatment due to AEs was low (2.4%). Results are summarized for efficacy-evaluable patients treated at the 4 dose levels where at least a partial response (PR) was achieved (750 mg, 1000 mg, 375 mg bid and 500 mg bid) (n = 55). During cycle 1, 89% experienced a ≥ 25% increase in absolute lymphocyte count (ALC), which usually resolved with continued treatment. The table below details the best responses achieved to date. In subjects with del11q, del17p, unmutated IgVH, and no high-risk genomic factors, the PR rate was 42% (5/12), 25% (3/12), 44% (7/16), and 47% (7/15), respectively. Importantly, nodal responses were induced in the majority of subjects receiving BID dosing (375 mg: 67%; 500 mg: 62%) with an overall PR rate of 40%. When achieved, nodal responses were typically observed by cycle 2 and were sustained with continued treatment. Although the sample size is small, subjects treated at 375 mg or 500 mg BID showed continued lymph node size reduction over time from cycle 2 (mean reduction of 42% and 45%, respectively) to cycle 7 (mean reduction of 60% and 71%, respectively). Conclusion CC-292 is well tolerated as an oral daily therapy. Single-agent therapy with CC-292 is sufficient to achieve high nodal and partial response rates in relapsed/refractory CLL subjects, including those with high-risk genomic features. These results support continued development of CC-292 for the treatment of patients with CLL/SLL. Disclosures: Brown: Pharmacyclics: Consultancy; Genentech: Consultancy; Celgene: Consultancy, Research Funding; Emergent: Consultancy; Onyx: Consultancy; Sanofi Aventis: Consultancy; Vertex: Consultancy; Novartis: Consultancy; Genzyme: Research Funding. Off Label Use: The abstract shows scientific information on CC292 which is an investigational product developed by Celgene. This investigational product is not approved by any health authority for any indication. Harb:Celgene: Research Funding. Hill:Celgene: Honoraria, Research Funding. Sharman:Celgene: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Gilead: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Cylene Pharmaceuticals: Consultancy, Research Funding; Avila Pharmaceuticals: Consultancy, Research Funding. Barr:Celgene: Consultancy. Foran:Celgene: Research Funding. Burger:Pharmalytics: Research Funding; Gilead: Research Funding. Mahadevan:Novartis: Speakers Bureau; Millennium: Speakers Bureau. Ma:Genentech: Consultancy; Abbvie: Consultancy. Barnett:Celgene: Employment, Equity Ownership. Marine:Celgene: Employment, Equity Ownership. Nava-Parada:Celgene: Employment, Equity Ownership. Azaryan:Celgene: Employment, Equity Ownership. Mei:Celgene: Employment, Equity Ownership. Kipps:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding.