Doxil (D), Vincristine (V), Reduced Frequency Dexamethasone (d) and Revlimid(R) (DVd-R) Results in a High Response Rate in Patients with Refractory Multiple Myeloma (RMM).

Background: The combination of DVd with Thalidomide (T) results in a high response rate (greater than 80% with about 50% of patients achieving a CR or NCR) in multiple myeloma. Revlimid, an immunomodulatory drug (IMiD) is active in patients with MM. We previously reported on a phase I trial of DVd-R in patients with MM, in which the maximum tolerated dose of R was 10mg daily.

Methods: The DVd-R regimen was given as follows: on day 1 D was given at 40 mg/m² IVPB; V at 2 mg IVP; d at 40 mg PO daily for 4 days, R was started at 10mg daily. R was given for 21 days consecutively. For the first cycle R was started 7 days prior to chemotherapy, while it was started on day 1 on subsequent cycles (cycle 1 was 35 days). DVd was planned every 28 days for 2 cycles after best response or a minimum of 4 cycles. Maintenance therapy consisted of R +/− Prednisone 50 mg Qod. All patients received amoxicillin, acyclovir and aspirin 81mg prophylactically. Responses were assessed based on the criteria set forth by SWOG.

Patients: The study accrued 58 patients to date (36 refractory and 22 relapsed patients), 45 are evaluable for response. The median patient age at the start of the study is 62 years and 74% are males. The median number of prior chemotherapeutic regimen is 3 (range 1–7), 67% of patients had progressed after a Thalidomide containing regimen, 70% had received a VAD like regimen and 17% had received a prior autologous stem cell transplant. The median time from diagnosis to study entry is 39 month (range 5–182). Eighty six percent had Durie Salomon stage III. The mean serum B2microglobin was 6.6mg/dL (s.d.4.2).

Results: The median number of cycles of DVd-R delivered was 4. Of evaluable patients, 6 patients had a CR (13%), 5 had a NCR (11%), 16 had a PR (35%), 11 had stable disease (24%), and 7 had progressive disease (15%) as their best response. The median time to best response was 38 days. After a median follow up of 7.3 month (range 0–24 months), 23 patients had progressive disease and 16 patients had died. Fifty two percent of refractory patients (19/36) had a response on DVd-R. Grade 3 and 4 leukopenia occurred in 24% and 15% respectively, however febrile neutropenia occurred in only 1 patient. Grade 3 and 4 infections occurred in 26% and 3% respectively (all but one were pneumonia). Grade 3 thrombocytopenia occurred in 20%. Venous thromboembolic events occurred in 5 patients (9%) (2 patients with pulmonary embolus and 4 with deep venous thrombosis). Grade 3 neuropathy occurred in 3 patients (no patients had grade 4 neuropathy). Two patients developed grade 3 tumor lysis syndrome.

Conclusion: DVd-R is an effective chemotherapeutic regimen in patients with RMM who progressed or did not respond to VAD like regimens or to Thalidomide containing regimens, produces a high response rate among chemotherapy resistant patients, and has a manageable toxicity profile. The results will be updated at the time of the meeting.