oprozomib and pomalidomide

Oprozomib (OPZ or ONYX 0912) is an irreversible, orally administered proteasome inhibitor (PI) and an analog of carfilzomib. We set out to determine the anti-angiogenic effect of OPZ using the choriollantoic membrane/feather bud (CAM/FB) model and its anti-MM effects using MM xenograft models (LAGκ-1A, LAGλ-1). OPZ significantly reduced blood vessel formation, endothelial gene and protein expression using the CAM/FB assay. In vivo, we determined the anti-MM effects of OPZ, dexamethasone (Dex) and pomalidomide (Pom) and showed that the combinations of two drugs (OPZ+Dex or OPZ+Pom) showed marked anti-MM effects when compared to monotherapy. Pom+Dex and the triplicate combination (OPZ+Pom+Dex) showed more anti-MM effects when compared to the doublets of either OPZ+Dex or OPZ+Pom; continued treatment with all three drugs (OPZ+Pom+Dex) was superior when compared to Pom+Dex, in both MM xenograft models tested. These studies show that OPZ has anti-angiogenic effects, and that the combination of OPZ, Dex and Pom produces greater anti-MM effects in vivo when compared to any of the doublet combinations. These studies provide further support for clinical trials evaluating OPZ in combination with Pom and Dex.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Dexamethasone; Humans; Male; Mice; Mice, SCID; Multiple Myeloma; Neovascularization, Pathologic; Oligopeptides; Thalidomide; Xenograft Model Antitumor Assays

This phase Ib study evaluated oprozomib, an oral proteasome inhibitor, plus pomalidomide-dexamethasone in relapsed/refractory multiple myeloma (RRMM).. Patients received oprozomib once-daily on days 1 to 5 and 15 to 19 (5/14 schedule; 150 mg/day starting dose) or on 2 consecutive days weekly (2/7 schedule; 210 mg/day starting dose) of 28-day cycles, pomalidomide on days 1 to 21 (4 mg/day starting dose), and dexamethasone 20 mg on 2 consecutive days weekly. A 3 + 3 dose-escalation schema was used to determine the maximum tolerated dose.. Thirty-one patients were treated (5/14, n = 4; 2/7, n = 27). Oprozomib maximum tolerated dose was not defined. The 2/7 schedule (oprozomib 210 mg/day, pomalidomide 4 mg/day) was selected for dose expansion based on overall safety (n = 17). In this group, the most common adverse events (AEs) were gastrointestinal (diarrhea [88.2%], nausea [58.8%], and vomiting [58.8%]); grade ≥ 3 gastrointestinal AEs were uncommon. The most common grade ≥ 3 AEs were hematologic (anemia [47.1%], neutropenia [35.3%], and thrombocytopenia [29.4%]). One dose-limiting toxicity (gastric hemorrhage) occurred; 3 patients discontinued owing to AEs. The overall response rate was 70.6%.. Safety and pharmacokinetic profiles were concerns with the oprozomib formulation used in this study and need to be improved. Oprozomib-pomalidomide-dexamethasone (2/7 schedule) had encouraging efficacy, supporting an ongoing phase Ib study evaluating new oprozomib formulations for this combination in relapsed/refractory multiple myeloma.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Dexamethasone; Drug Administration Schedule; Drug Resistance, Neoplasm; Female; Humans; Male; Middle Aged; Multiple Myeloma; Neoplasm Recurrence, Local; Neoplasm Staging; Oligopeptides; Research Design; Retreatment; Thalidomide