Abstract

In MM, tumor microenvironment (ME) plays an important role in disease progression, dissemination, and development of resistance to therapy. Pts with rel/ref MM have limited treatment options. Therefore, targeting the ME simultaneously with malignant cells may be an effective way to overcome resistance in pts with rel/ref MM. Orlowski et al recently reported synergistic activity of V+D in patients with hematologic malignancies. A phase II trial initiated at our institute is exploring this approach, targeting the MM cell as well as its ME, using a combination of Velcade (V), Doxil (D) and low-dose thalidomide (T) as salvage therapy for pts with rel/ref MM. Pts with rel/ref disease are eligible for this study. V is given at 1.3mg/m2 (D1,4,15,18) and D at 20mg/m2 (D1,15) every 4 weeks with daily T (200 mg) for 4–6 cycles. SWOG criterion was used to evaluate response. Low-dose coumadin (1–2 mg po qd) was used for prevention of venous thromboembolism (VTE). Eighteen pts (7M, 11F; median age 56, range 44–80 yrs; 16MM, 2 WM) have been enrolled to date. All pts had Stage III disease, median b2M of 4.8 (nl range: 0–2.15) and median prior therapies 2 (range 1–7). Prior therapies included stem cell transplant in (46%), T (54%), adriamycin(A) (70%) and steroids (92%). Thirteen pts have completed at least 1 cyc and are available for toxicity and response evaluation. One pt died of sepsis prior to completing 1 cyc and 1 pt with PR was taken of study for non-compliance after 1 cyc. ORR was 100% (13/13) with 5PR and 8MR. All pts are currently continued on therapy. Toxicity: 2 pts developed Gr. II plantar-palmar erythrodysthesia (PPE) and 1 had Gr. III cellulitis. No VTE was noted. VDT is a highly active salvage regimen in pts with rel/refr MM. Responses were noted despite prior failure of steroids, T or A. It is well tolerated without any significant non-hematologic Gr. III/IV toxicity. VTE does not appear to be a problem. Updated results of this first cohort of pts will be presented at the annual ASH meeting.

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