Adding pomalidomide to bortezomib and dexamethasone for multiple myeloma

This study examined the effects of pomalidomide (Pomalyst) in combination with bortezomib (Velcade) and dexamethasone (Decadron) in patients with relapsed or refractory multiple myeloma. This treatment combination was considered safe and effective for previously treated multiple myeloma.

Standard treatment for multiple myeloma involves giving high doses of chemotherapy and replacing blood-forming cells destroyed by the cancer treatment with a stem cell transplant. This has significantly improved response and survival rates among patients. However, many patients will relapse over time. Other patients may stop responding to standard treatment. This is known as refractory disease.

New treatment options are needed for patients who have received multiple prior treatments. Pomalidomide is a type of biologic therapy that uses the patient's immune system to fight cancer. Early studies have reported promising results with pomalidomide for previously treated multiple myeloma. However, it is not clear whether this treatment can be safely combined with other common treatments, such as the chemotherapy bortezomib or the steroid dexamethasone.

The aim of this study was to assess the safety and dosages of this treatment combination.

34 patients with relapsed or refractory multiple myeloma were included. On average, patients had received 2 previous lines of treatment. 97% had previously been treated with bortezomib. 68% had undergone a stem cell transplant. All patients received the same treatment combination in 21-day cycles. Low-dose dexamethasone was administered on days of and after bortezomib.

The average length of treatment was 6.2 months. The average number of treatment cycles was 9. 65% responded to treatment. The average time to treatment response was 7.4 months.

Based on the rate of side effects, the maximum tolerated dose for pomalidomide was 4 mg. It was 1.3 mg/m2 for bortezomib and 20 mg for dexamethasone. Patients over the age of 75 tolerated dexamethasone at 10 mg.

The most common serious side effects were low blood cell counts. 44% of patients had low levels of neutrophils (white blood cells) and 26% had low levels of platelets (cells involved in clotting). This more common in patients receiving bortezomib by injection into the vein. 53% of patients experienced pain or numbness in hands and feet. However, these cases were not considered serious.

Researchers reported that combining pomalidomide with bortezomib and dexamethasone is safe and effective in previously treated multiple myeloma patients.

Larger studies are needed to confirm these results.