Pomalidomide Plus Low-Dose Dexamethasone in Patients With Relapsed/Refractory Multiple Myeloma and Renal Impairment: Results From a Phase II Trial

Purpose Renal impairment (RI) limits treatment options in patients with relapsed/refractory multiple myeloma (RRMM). Here, we prospectively studied pomalidomide plus low-dose dexamethasone (LoDEX) in patients with RRMM and moderate or severe RI, including those receiving hemodialysis. Patients and Methods MM-013, a noncomparative, European phase II trial, enrolled three patient cohorts: moderate RI (cohort A; estimated glomerular filtration rate, 30 to < 45 mL/min/1.73 m²); severe RI (cohort B; estimated glomerular filtration rate, < 30 mL/min/1.73 m²); and severe RI that requires hemodialysis (cohort C). Patients received pomalidomide 4 mg/d on days 1 to 21 and LoDEX 20 or 40 mg once per week in 28-day cycles. The primary end point was overall response rate. Results Of 81 enrolled patients (33, 34, and 14 patients in cohorts A, B, and C, respectively), 13 were still receiving treatment at data cutoff (January 28, 2017). Overall response rates were 39.4%, 32.4%, and 14.3%, with a median duration of response of 14.7 months, 4.6 months, and not estimable, respectively. Of importance, 100%, 79.4%, and 78.6% of patients, respectively, achieved disease control. With a median follow-up of 8.6 months, median overall survival was 16.4 months, 11.8 months, and 5.2 months, respectively. Complete renal responses were observed only in cohort A (18.2%), and no patients in cohort C became hemodialysis independent. Grade 3 and 4 hematologic treatment-emergent adverse events and pomalidomide discontinuations as a result of treatment-emergent adverse events occurred more frequently in cohort C. Pomalidomide pharmacokinetics were comparable among the three renal cohorts. Conclusion Pomalidomide 4 mg/d plus LoDEX is efficacious in patients with RRMM with moderate or severe RI, including those who had more advanced disease and required hemodialysis. The safety profile was acceptable among the three groups, and no new safety signals were observed.