A phase Ib, open label, dose escalation trial of the anti-CD37 monoclonal antibody, BI 836826, in combination with ibrutinib in patients with relapsed/refractory chronic lymphocytic leukemia.

BI 836826 is a chimeric immunoglobulin G1 antibody targeting CD37, a transmembrane protein expressed on normal and malignant B cells. This open-label, phase Ib, dose-escalation study was conducted to determine the recommended phase II dose (RP2D) of BI 836826 + ibrutinib in patients with relapsed/refractory chronic lymphocytic leukemia (CLL). Eligible patients received 420 mg/day of ibrutinib with escalating doses of BI 836826. BI 836826 was administered in 4-week cycles. After Cycle 12, patients achieving complete response (CR), CR with incomplete marrow recovery, or minimal residual disease-negative partial response could continue to receive BI 836826 + ibrutinib every 4 weeks for ≤ 12 additional cycles. Patients received either 100 mg (n = 3) or 200 mg (n = 3) BI 836826 + ibrutinib. In the 100 mg BI 836826 cohort, one patient received two cycles and two patients received 22 cycles of BI 836826. In the 200 mg BI 836826 cohort, patients received 12, 16 and 20 cycles of BI 836826, respectively. All patients discontinued BI 836826 and continued ibrutinib outside the trial. No dose-limiting toxicities were reported in the maximum tolerated dose (MTD) evaluation period. As the trial was discontinued before the MTD was reached, the RP2D was not determined. Grade 3/4 adverse events (AEs) were predominantly hematological. Pseudomonal bacteremia was the only drug-related AE of special interest. BI 836826 + ibrutinib did not exceed the MTD at doses up to 200 mg in patients with CLL. However, RP2D and MTD were not formally established, as the sponsor discontinued the trial.

A phase Ib, open-label, dose-escalation trial of the anti-CD37 monoclonal antibody, BI 836826, in combination with gemcitabine and oxaliplatin in patients with relapsed/refractory diffuse large B-cell lymphoma.

Background BI 836826 is a chimeric mouse-human monoclonal antibody directed against human CD37, a transmembrane protein expressed on mature B lymphocytes. This open-label, phase I dose-escalation trial (NCT02624492) was conducted to determine the maximum tolerated dose (MTD), safety/tolerability, and preliminary efficacy of BI 836826 in combination with gemcitabine and oxaliplatin in patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL). Methods Eligible patients received intravenous infusions of BI 836826 on day 8 and gemcitabine 1000 mg/m2 plus oxaliplatin 100 mg/m2 on day 1, for up to six 14-day treatment cycles. Dose escalation followed the standard 3 + 3 design. Results Of 21 treated patients, 17 had relapsed/refractory DLBCL and four had follicular lymphoma transformed to DLBCL. BI 836826 dosing started at 25 mg and proceeded through 50 mg and 100 mg. Two dose-limiting toxicities (DLTs) occurred during cycle 1, both grade 4 thrombocytopenia lasting > 7 days, affecting 1/6 evaluable patients (17%) in both the 50 mg and 100 mg cohorts. Due to early termination of the study, the MTD was not determined. The most common adverse events related to BI 836826 treatment were neutropenia (52%), thrombocytopenia (48%), and anemia (48%). Eight patients (38%) experienced BI 836826-related infusion-related reactions (two grade 3). Overall objective response rate was 38%, including two patients (10%) with complete remission and six patients (29%) with partial remission. Conclusions BI 836826 in combination with GemOx was generally well tolerated but did not exceed the MTD at doses up to 100 mg given every 14 days.

Phase I dose escalation study of BI 836826 (CD37 antibody) in patients with relapsed or refractory B-cell non-Hodgkin lymphoma.

BI 836826 is a chimeric immunoglobulin G1 antibody targeting CD37, a tetraspanin transmembrane protein predominantly expressed on normal and malignant B cells. This phase I, open-label study used a modified 3 + 3 design to evaluate the safety, maximum tolerated dose (MTD), pharmacokinetics, and preliminary activity of BI 836826 in patients with relapsed/refractory B cell non-Hodgkin lymphoma (NHL; NCT01403948). Eligible patients received up to three courses comprising an intravenous infusion (starting dose: 1 mg) once weekly for 4 weeks followed by an observation period of 27 (Course 1, 2) or 55 days (Course 3). Patients had to demonstrate clinical benefit before commencing treatment beyond course 2. Forty-eight patients were treated. In the dose escalation phase (1-200 mg) involving 37 Caucasian patients, the MTD was 100 mg. Dose-limiting toxicities occurred in four patients during the MTD evaluation period, and included stomatitis, febrile neutropenia, hypocalcemia, hypokalemia, and hypophosphatemia. The most common adverse events were neutropenia (57%), leukopenia (57%), and thrombocytopenia (41%), and were commonly of grade 3 or 4. Overall, 18 (38%) patients experienced infusion-related reactions, which were mostly grade 1 or 2. Preliminary evidence of anti-tumor activity was seen; three patients responded to treatment, including one complete remission in a Korean patient with diffuse large B cell lymphoma. BI 836826 plasma exposure increased more than proportionally with increasing doses. BI 836826 demonstrated preliminary activity; the most frequent adverse events were hematotoxicity and infusion-related reactions which were manageable after amending the infusion schedule. Although BI 856826 will not undergo further clinical development, these results confirm CD37 as a valid therapeutic target in B cell NHL.

Emerging immunological drugs for chronic lymphocytic leukemia.

INTRODUCTION: Over the last few years, several new immunological drugs, particularly monoclonal antibodies (mAbs), immunomodulatory drugs and B-cell receptor (BCR) pathway inhibitors have been developed and investigated in chronic lymphocytic leukemia (CLL). This article summarizes recent discoveries regarding their mechanism of action, pharmacological properties, clinical activity and toxicity, as well as the emerging role of these agents in CLL. AREAS COVERED: A literature review of mAbs, BCR pathway inhibitors and immunomodulating drugs was conducted of the MEDLINE database via PubMed for articles in English. Publications from 2000 through February 2015 were scrutinized. The search terms used were alemtuzumab, BI 836826, duvelisib ibrutinib, idelalisib, lenalidomide, monoclonal antibodies, MEDI-551, MOR208, obinutuzumab, ocaratuzumab, ofatumumab, ONO-4059, otlertuzumab, spebrutinib, veltuzumab and XmAb5574 in conjunction with CLL. Conference proceedings from the previous 5 years of the American Society of Hematology, European Hematology Association, American Society of Clinical Oncology, and ACR/ARHP Annual Scientific Meetings were searched manually. Additional relevant publications were obtained by reviewing the references from the chosen articles. EXPERT OPINION: The use of mAbs, BCR inhibitors and immunomodulating drugs is a promising new strategy for chemotherapy-free treatment of CLL. However, definitive data from ongoing and future clinical trials will aid in better defining the status of immunological drugs in the treatment of this disease.