Pomalidomide plus cyclophosphamide and dexamethasone (PomCyDex) resulted in a higher overall response rate as compared with pomalidomide plus low-dose dexamethasone (PomDex) in patients with refractory multiple myeloma, a study published in the journal Blood has shown.1

Because PomDex is a standard treatment for patients refractory to lenalidomide who have received 3 or more prior therapies, researchers sought to evaluate the safety and efficacy of adding oral weekly cyclophosphamide to PomDex in the refractory setting.

Researchers first conducted a dose escalation phase 1 study with 10 patients to determine the maximum tolerated phase 2 dose of cyclophosphamide in combination with PomDex. A dose of 400 mg was identified as the recommended dose.

Then for the multicenter phase 2 study, researchers enrolled 70 patients and randomly assigned them 1:1 to receive pomalidomide 4 mg on days 1 to 21 of each 28-day cycle in combination with weekly dexamethasone, or PomDex plus cyclophosphamide 400 mg orally on days 1, 8, and 15 of each 28-day cycle.

Results showed that overall response rate was 38.9% (95% CI, 23 – 54.8) with PomDex and 64.7% (95% CI, 48.6 – 80.8) with PomCyDex (P = .035); however, at the time of this analysis, 62 of the 70 patients had experienced disease progression.

Researchers found that the median progression-free survival was 4.4 months (95% CI, 2.3 – 5.7) and 9.5 months (95% CI, 4.6 – 14) for PomDex and PomCyDex, respectively (P = .106).

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In terms of safety, there was no significant increase in toxicity with the addition of cyclophosphamide compared with PomDex alone. Most treatment-related adverse events were hematological toxicities.

The findings ultimately suggest that PomCyDex is an effective oral regimen for patients with refractory multiple myeloma.

Reference

  1. Baz RC, Martin, TG III, Lin H-Y, et al. Randomized multicenter phase II study of pomalidomide, cyclophosphamide, and dexamethasone in relapsed refractory myeloma [published online ahead of print March 1, 2016]. Blood. doi: 10.1182/blood-2015-11-682518.