Marizomib, pomalidomide and dexamethasone in relapsed or refractory multiple myeloma

This paper studied the safety and efficacy of marizomib, pomalidomide (Pomalyst) and dexamethasone (Ozurdex) in the treatment of relapsed or refractory multiple myeloma. The authors concluded the treatment was well tolerated and effective. 

Multiple myeloma is a cancer of the plasma cells (type of white blood cell). It is incurable, and following treatment, many patients are refractory (do not respond to treatment) or relapse (have a return of cancer). Marizomib is a new drug that has been developed to treat multiple myeloma. A unique feature of marizomib is that it can cross the blood brain barrier. Pomalidomide, together with dexamethasone, are other treatments that have been approved for the treatment of relapsed or refractory multiple myeloma. 

36 patients with relapsed or refractory multiple myeloma were analyzed. They received an average of 4 cycles of treatment with marizomib, pomalidomide and dexamethasone over an average 16 weeks.

Overall, 53% of patients responded to treatment. 11% patients had a minimal response to treatment. 28% of patients had no change in disease. 8% of patients had worsening disease. The average duration of response was 7.5 months from an average follow-up period of 12.9 months. After an average follow-up period of 11.2 months, patients survived an average 4 months without worsening disease. After a median follow-up of 15.7 months, the average overall survival (time from treatment until death from any cause) was 13.6 months.

With regards to safety, 92% of patients had a treatment-related adverse event (undesired effect of treatment). 29% of patients had low levels white blood cells. 11% of patients had low levels of red blood cells. 26% of patients experienced fatigue. 18% of patients experienced shortness of breath. 13% of patients had pneumonia. Two deaths occurred during the study, of which one was due to cardio-respiratory arrest from pomalidomide and one due to worsening disease. 

The authors concluded that marizomib and pomalidomide were well tolerated, and show promise in the treatment of relapsed or refractory multiple myeloma.  

Further studies are needed, as this was a phase 1 (early) trial.