The combination of pomalidomide, cyclophosphamide, and dexamethasone (PCD) therapy may be effective for patients with multiple myeloma who experience relapse after being treated with lenalidomide, bortezomib, and dexamethasone (RVD), according to a study published in Blood.
In this multicenter, phase 2 trial, 100 patients with multiple myeloma who had previously received RVD therapy followed by lenalidomide maintenance for 1 year were enrolled into 2 study arms. Patients in arm A received 4 cycles of PCD, underwent an autologous stem cell transplant (ASCT), and then received 2 more cycles of PCD. Patients in arm B received an ASCT after RVD induction and received 9 consecutive cycles of PCD.
Patients received 4 mg pomalidomide per day for 21 days in 28-day cycles, 300 mg cyclophosphamide per week, and 40 mg dexamethasone per day at regular intervals in 28-day cycles. The primary endpoint was the proportion of patients who achieved partial remission or better after 4 cycles of PCD with upfront or delayed ASCT. Secondary endpoints included time to response, response duration, safety and efficacy of PCD, and progression-free and overall survival (PFS; OS).
Partial remission or better was observed in 85% of evaluable patients: 51% of patients achieved partial remission, 33% of patients achieved very good partial remission, and 1% of patients achieved complete remission. Additionally, 3% of patients had stable disease and 6% of patients did not respond to treatment, which led to disease progression.
A total of 34 patients experienced disease progression and 15 patients died. Overall, PFS at 12, 24, and 36 months after PCD treatment initiation in arm A was 89.4%, 79.6%, and 54.5%, respectively, and in arm B the rates were 78.8%, 55.9%, and 40.0%, respectively. OS at 12, 24, and 36 months after PCD initiation in arm A was 98.0%, 95.9%, 84.2%, respectively, and 98.0%, 88.7%, 85.8%, respectively, for arm B.
Adverse events were experienced by 73 patients and included mostly hematologic toxicities and infections. However, these adverse events were manageable and comparable to adverse events experienced by patients treated with pomalidomide and dexamethasone.
The authors concluded that PCD was associated with prolonged PFS and OS and constituted a highly effective and safe second-line treatment in patients previously treated with RVD. They suggested that “addition of a monoclonal antibody could increase the efficacy [of PCD] further.”
1. Garderet L, Kuhnowski F, Berge B, et al. Pomalidomide, cyclophosphamide, and dexamethasone for relapsed multiple myeloma [published online October 4, 2018]. Blood. doi: 10.1182/blood-2018-07-863829