Population Pharmacokinetics and Exposure Response Analysis of Pomalidomide in Subjects With Relapsed or Refractory Multiple Myeloma From the Novel Combination Treatment of Pomalidomide, Bortezomib, and Low-Dose Dexamethasone

Multiple myeloma is an incurable progressive neoplastic disease that accounts for 10% of all hematologic malignancies. Even though significant progress has been made in the treatment of newly diagnosed multiple myeloma, the disease follows a relapsing course in the majority of patients, and there is a need for more effective therapeutic options for the treatment of relapsed or refractory multiple myeloma. CC-4047-MM-005 and CC-4047-MM-007 were phase 1 and 3 studies to evaluate the novel combination of pomalidomide, bortezomib, and low-dose dexamethasone for the treatment of patients with relapsed or refractory multiple myeloma who have already received lenalidomide-based treatments early. This analysis was performed to characterize the population pharmacokinetics (PK) of pomalidomide from the combination treatment and to examine exposure-response relationships. Our analysis showed that pomalidomide concentration-time profiles from the combination treatment were adequately described with a 1-compartment PK model, with first-order absorption and elimination and pomalidomide exhibiting linear and time-invariant PK with moderate variability from the combination treatment. Except for the body surface area, none of the tested covariates had an effect on pomalidomide PK. Although body surface area was identified as a statistically significant covariate of pomalidomide PK, the impact was not deemed clinically relevant. A flat exposure-response curve was observed, consistent with a near-saturated drug effect at the tested exposure range suggesting an appropriately recommended clinical dose of 4 mg of pomalidomide for the combination treatment. Finally, pomalidomide exposure was not associated with higher probabilities of dose interruption during cycle 1 or dose reduction during the treatment period.

A phase 1 clinical trial evaluating marizomib, pomalidomide and low-dose dexamethasone in relapsed and refractory multiple myeloma (NPI-0052-107): final study results

Marizomib (MRZ) is an irreversible, pan-subunit proteasome inhibitor (PI) in clinical development for relapsed/refractory multiple myeloma (RRMM) and glioma. This study analysed MRZ, pomalidomide (POM) and low-dose dexamethasone (Lo-DEX) [PMD] in RRMM to evaluate safety and determine the maximum tolerated dose (MTD) and/or recommended Phase 2 dose (RP2D). Intravenous MRZ (0·3-0·5 mg/m² ) was administered over 2 h on days 1, 4, 8, 11; POM (3-4 mg) on days 1-21; and Lo-DEX (5 or 10 mg) on days 1, 2, 4, 5, 8, 9, 11, 12, 15, 16, 22 and 23 of every 28-day cycle. Thirty-eight patients were enrolled that had received a median of 4 (range 1-10) prior lines of therapy; all patients received prior lenalidomide and bortezomib. No dose-limiting toxicities (DLTs) were observed and 0·5 mg/m² MRZ was determined to be the RP2D. The most common treatment-related ≥Grade 3 adverse events were: neutropenia (11/38 patients: 29%), pneumonia (4/38 patients 11%), anaemia (4/38 patients; 11%) and thrombocytopenia (4/38 patients; 11%). The overall response rate and clinical benefit rate was 53% (19/36) and 64% (23/36), respectively. In conclusion, PMD was well tolerated and demonstrated promising activity in heavily pre-treated, high-risk RRMM patients.