Safe and prolonged survival with long-term exposure to pomalidomide in relapsed/refractory myeloma

Pomalidomide and dexamethasone favored prolonged and safe OS, 91% at 18 months in 40% of heavily and end-stage relapse and refractory MM, to the opposite of the natural history of myeloma characterized with a succession of shorter disease-free intervals and ultimately shorter survival. This striking OS improvement demonstrates a shift in paradigm in relapse refractory myeloma exposed to pomalidomide.The IFM2009-02 trial studied pomalidomide (4 mg daily, 21/28 versus 28/28) and dexamethasone in very advanced relapsed or refractory multiple myeloma (RRMM). We observed that 40% of patients had a prolonged progression-free survival (PFS) and subsequently overall survival (OS). We sought to analyze the characteristics of these patients and study the effect of long exposure to pomalidomide. We separated the studied population into two groups: 3 months to 1 year (< 1 year) and more than 1 year (a parts per thousand yen1 year) of treatment with pomalidomide and dexamethasone based on clinical judgment and historical control studies. We then analyzed the characteristics of patients according to duration of treatment. The overall response rate (ORR) for the < 1-year group was 43%, the median PFS 4.6 months [95% confidence interval (95% CI) 3.8-6.4] with only 6% at 12 months, and the median OS was 15 months (11.7-20.3) and 40% at 18 months. For the a parts per thousand yen1-year group, the response rate and survival were strikingly different, ORR at 83%, median PFS 20.7 months (14.7-35.4), median OS not reached, and 91% at 18 months. Pomalidomide and dexamethasone favored prolonged and safe exposure to treatment in 40% of heavily treated and end-stage RRMM, a paradigm shift in the natural history of RRMM characterized with a succession of shorter disease-free intervals and ultimately shorter survival. Although an optimization of pomalidomide-dexamethasone regimen is warranted in advanced RRMM, we claim that pomalidomide has proven once more to change the natural history of myeloma in this series, which should be confirmed in a larger study.