Two Phase 2 studies presented at this year's ASH conference show that a new treatment regimen achieves 86 percent to 98 percent responsiveness in relapsed/refractory and newly diagnosed multiple myeloma patients.

Known as Rev/Vel/Dex, the treatment is a cocktail of three commonly prescribed multiple myeloma drugs -- Revlimid ^[1] (lenalidomide), Velcade ^[2] (bortezomib), and dexamethasone ^[3]. Both studies started patients on the same maximum dosage of 25 mg Revlimid, 1.3 mg/m² Velcade, 20 mg dexamethasone, and dosages were adjusted according to individual responses.

Both relapsed/refractory and newly diagnosed patients responded comparably in spite of pre-existing factors.

No differences were observed between patients with or without unfavorable cytogenetics. Prior treatment or a refractory condition also were not reflected in the success rate. Disease progression did not affect the efficacy of the drug; patients at stages 1, 2, and 3 disease shared comparable success in their responses to the therapy. In addition, several patients have successfully collected stem cells for autologous stem cell transplantation following treatment.

The first study included 64 total patients. Patients had received an average of one to three prior therapies, including Revlimid, Velcade, thalidomide, and stem cell transplant. Patients were treated until the disease progressed. To date, 31 patients have completed eight cycles, and 24 continue on maintenance.

Of the patients, 86 percent of relapsed or refractory patients achieved partial to complete responses, including 24 percent with a complete response.

The second study enrolled 68 newly diagnosed multiple myeloma patients, split into two groups. Thirty-three were placed in dosing research (Phase 1), and 35 patients helped assess the toxicity and efficacy of the drug (Phase 2). The patients received a median of ten cycles, and two-thirds have completed all eight cycles.

Overall response rate for the newly diagnosed patients was 98 percent. Specifically, 36 percent of participants attained complete or near-complete response and 71 percent completed the therapy with a very good partial response. The disease has not progressed in patients after a median 8-month follow-up period.

The most common side effect in the relapsed and refractory patients was myelosuppression, in which decreased bone marrow activity leads to fewer red and white blood cells and platelets. Other common side effects included deep vein thrombosis (blood clot, from Revlimid), atrial fibrillation (irregular heartbeat, from dexamethasone), and peripheral neuropathy (pain and numbness in the hands and feet, from Velcade). Dose reductions were required for 9 to 26 patients for all three drugs. One death, thought to be due to fungal pneumonia, may have been related to dexamethasone.

For newly diagnosed patients, side effects were moderate in severity, and included hyperglycemia (high blood sugar levels), hematological toxicities (i.e., anemia), hypophosphatemia (low blood phosphate levels), and deep vein thrombosis/pulmonary emobolism (blood clots). Two of the patients experienced difficulty with moving around. No patients reported peripheral neuropathy, and there were no treatment-related deaths.

For more information, refer to Abstracts 1742 ^[4] (relapsed/refractory) and 92 ^[5] (newly diagnosed) on the ASH website.