Doxil (D), Vincristine (V), Reduced Frequency Dexamethasone (d) and Revlimid(R) (DVd-R) a Phase I/II Trial in Advanced Relapsed/Refractory Multiple Myeloma (RMM) Patients.

DVd in combination with Thalidomide (T) and the appropriate supportive care measures resulted in a high response rate (88%) as well as an improved quality response (50% CR & NCR) similar to what is achieved with high dose therapy. Immunomodulatory drugs (IMiDs) are potent T derivatives. R is 50 to 2000 times more potent than T in stimulating T-cell proliferation triggered via the T-cell receptor, and 50 to 100 times more potent than T in augmenting IL-2 and IFN-a production. A recent phase I trial showed responses of at least 25% reduction in paraprotein in 17 (71%) of 24. We therefore initiated a phase I/II trial to define MTD of R in combination with DVd, then we proceeded to expand the MTD dose level to evaluate the efficacy and safety of the combination in patients with Rmm. SWOG criteria were used to assess response, and NCR was defined as a decrease of the M-Protein by >90%. Refractory patients were defined as those patients progressing on active therapy. R was started a week prior to DVd in cycle 1 to evaluate different coagulation parameters, from there on R was started on day 1 of therapy. The 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 X 4 days; R was started at 5 mg a day for 21 days with one week off. A standard phase 1 dose escalation of R was performed to identify the MTD. 3 pts were enrolled at each dose level, with up to 6 pts assigned to each dose level, depending on DLT. DVd was repeated q 4W, for a minimum of 4 cycles & 2 cycles after best response. Pts were maintained on R +/− prednisone 50 mg QOD. All patients received amoxicillin, acyclovir and aspirin 81mg prophylactically. 25 pts Rmm pts are enrolled with 21 evaluable for toxicity and mature data available for response on 21 pts (refractory: 15 (71%); relapsed: 6 (29%). 17/21 patients were stage 3, median age of 62 ± 9 years, baseline b₂ microglobulin level (mean 5.04 ± 2) and serum albumin (mean 3.4 ± 0.7). 14/21 patients failed T containing regimens. The DLT was sepsis/septic shock that occurred at dose level 3 (R 15mg) with two of the patients developing non neutropenic sepsis. The MTD for R was defined at 10mg. Three patients started therapy with a neutrophil count < 500/mL and or platelet counts < 50k/mL; all 3 patients were responders. There was one grade 4 hyper-coagulation event in the form of a PE that has recovered. This event occurred in a refractory patient with renal failure performance status of 3 who achieved CR after 2 cycles. In the expanded cohort there was 2 grade 3 neutropenia & one grade 3 neuropathy requiring dose reductions of R and D in each pt with resolution of the neutropenia and neuropathy. 3/21 (14%) patients achieved CR, 4/21 (19%) NCR. All CR+NCR patients (33%) are refractory patients. An additional 7 pts achieved PR, and 6 SD 5 of whom showing greater than 25% decrease in the m-protein. All patients except for 4 achieved > 25% reduction of the m-protein after one cycle of therapy and 3/4 after 2 cycles. R at 10mg is the MTD in combination with the DVd in RMM. DVd-R is an extremely effective regimen with a SWOG response rate >66%, CR+NCR of 33% in refractory stage 3 patients with minimal toxicity.