The investigators report on the promising activity of a phase 1b trial of the targeted therapy triplet rituximab, ibrutinib, and lenalidomide in patients with relapsed non–germinal center diffuse large B-cell lymphoma (DLBCL).

Purpose This first-in-human study evaluated SGN-CD70A, an antibody-drug conjugate (ADC) directed against the integral plasma membrane protein CD70 and linked to a pyrrolobenzodiazepine (PBD) dimer, in patients with relapsed or refractory (R/R) CD70-positive non-Hodgkin lymphoma (NHL) including diffuse large B cell lymphoma (DLBCL), mantle cell lymphoma (MCL), and Grade 3b follicular lymphoma (FL3b). Methods SGN-CD70A was administered intravenously on Day 1 of 3-week cycles beginning at 8 mcg/kg with planned dose escalation to 200 mcg/kg. Due to observations of prolonged thrombocytopenia, the study was amended to dose every 6 weeks (q6wk). Results Twenty patients were enrolled and treated with SGN-CD70A. The maximum tolerated dose of SGN-CD70A was 30 mcg/kg q6wk. The most common adverse events (AEs) reported were thrombocytopenia (75%), nausea (55%), anemia (50%), and fatigue (50%). The onset for treatment-related thrombocytopenia typically occurred during Cycle 1. Most of the treatment-related events of thrombocytopenia were ≥ Grade 3. Antitumor activity in patients included 1 complete remission (CR) and 3 partial remissions (PRs), 2 of which were ongoing for at least 42.9 weeks. SGN-CD70A exposures were approximately dose proportional, with a mean terminal half-life of 3 to 5 days. Conclusions While modest single-agent activity was observed in heavily pretreated NHL patients, the applicability of SGN-CD70A is limited by the frequency and severity of thrombocytopenia, despite the long-term response with limited drug exposure.

CC‐486 (oral azacitidine) is an epigenetic modifier in clinical development for treatment of hematological cancers. This study of extended CC‐486 dosing included patients with myelodysplastic syndromes (MDSs), chronic myelomonocytic leukemia (CMML), or acute myeloid leukemia (AML). After a pharmacokinetic assessment period, 31 patients (MDS n = 18, CMML n = 4, and AML n = 9) entered a clinical phase in which they received CC‐486 300 mg once‐daily for 21 days of repeated 28‐day cycles. Median age was 71 years (range: 53‐93); 42% of patients were aged ≥75 years. A total of 5 patients with AML (63%) had prior MDS. Median number of CC‐486 treatment cycles was 4 (range: 1‐32). The most common treatment‐emergent adverse events (TEAEs) were gastrointestinal (84% of patients) and hematologic (81%). Most common grade 3‐4 TEAEs were neutropenia (n = 13, 42%) and anemia (n = 9, 29%). Ten patients experienced grade 4 neutropenia. Infrequently, CC‐486 dose was interrupted or reduced due to gastrointestinal (n = 5, 16%) or hematologic (n = 6, 19%) TEAEs. Overall response rate (complete remission [CR], CR with incomplete hematological recovery [CRi], partial remission [PR], marrow CR) in the MDS/CMML subgroups was 32% and in the AML subgroup (CR/CRi/PR) was 22%. Red blood cell transfusion independence rates in the MDS/CMML and AML subgroups were 33% and 25%, respectively, and 2 MDS/CMML patients attained hematologic improvement as a best response on‐study. No baseline gene mutation was predictive of response/nonresponse. CC‐486 allows flexible dosing and schedules to improve tolerability or response. Neutropenia in early treatment cycles deserves scrutiny and may warrant initiation of prophylactic antibiotics.KEY POINTSThe safety profile of oral CC‐486 was comparable to that of injectable azacitidine; most adverse events were hematological and gastrointestinal.Extended (21‐day/cycle) CC‐486 dosing induced responses in patients with hematological malignancies, many of whom had prior DNMTi failure.

Panobinostat is a histone deacetylase inhibitor that has shown synergistic preclinical anti-myeloma activity when combined with other agents, recently exhibiting synergy with the alkylating agent melphalan (Sanchez et al., Leuk Res 35(3):373-379, 2011). This phase 1/2 trial investigated the safety and efficacy of panobinostat in combination with melphalan for relapsed/refractory multiple myeloma patients. There were four different trial treatment schedules due to tolerability issues, with the final treatment schedule (treatment schedule D) consisting of panobinostat (15 or 20 mg) and melphalan (0.05 or 0.10 mg/kg), both administered on days 1, 3, and 5 of a 28-day cycle. A total of 40 patients were enrolled; 3 in treatment schedule A, 9 in schedule B, 7 in schedule C, and finally 21 schedule D. Patients had been treated with a median of four regimens (range, 1-16) and two prior bortezomib-containing regimens (range, 0-9). Maximum-tolerated dose was established at 20 mg panobinostat and 0.05 mg/kg melphalan in treatment schedule D. Overall, 3 patients (7.5 %) achieved ≥partial response (two very good PRs and one PR) while 23 exhibited stable disease and 14 showed progressive disease. All three responders were enrolled in cohort 2 of treatment schedule B (panobinostat 20 mg thrice weekly continuously with melphalan 0.05 mg/kg on days 1, 3, and 5). Neutropenia and thrombocytopenia were common, with 30.8 and 23.1 % of patients exhibiting ≥grade 3, respectively. Panobinostat + melphalan appears to have tolerability issues in a dosing regimen capable of producing a response. Care must be taken to balance tolerability and efficacy with this combination.

No abstract