Rituximab plus fludarabine was well tolerated and associated with an excellent complete response rate, including molecular remissions, in patients with low-grade or follicular lymphoma.

No abstract

Introduction: Bortezomib, a first in class proteasome inhibitor, has become a standard of care in the treatment of relapsed and refractory MM. A recent randomized Phase 3 trial showed an improvement in time to progression (TTP) and overall survival relative to dexamethasone (dex) in patients with relapsed MM and 1–3 prior lines of therapy. In relapsed MM, the rate of treatment -emergent significant peripheral neuropathy (PN) with bortezomib was higher in patients with baseline neuropathy. The incidence and severity of PN in front-line treatment will be important to define. This multi-center, Phase 2 study was planned to evaluate the activity and toxicity (in particular PN) of single agent bortezomib in previously untreated pts. Methods: Response rate, TTP, tolerability, incidence and severity of PN, and the effect of dose modification, symptomatic treatment and nutritional supplements on PN were evaluated in previously untreated, symptomatic MM pts. Pts received bortezomib 1.3 mg/m2 on D 1, 4, 8, and 11 of a 21-d cycle and response to treatment was assessed every 2 cycles. Dex was not permitted. Neurologic evaluation was required before and after treatment, and if significant PN developed during therapy. Results: 28 pts with symptomatic MM have been treated with a median age of 60 yrs, IgG isotype in 68% and Stage III disease in 52%. Analysis of best paraprotein response after ≥ 2 cycles revealed CR in 1 (5%) pt and PR in 8 (36%), for an ORR of 41% in 22 evaluable pts. An additional 5 pts (23%) achieved MR, with stable disease in 6 pts (27%); 2 pts progressed (9%). The most commonly reported adverse events included PN, fatigue, GI symptoms and rash. Neurological evaluation has been performed in all pts, including nerve conduction studies (NCS), assessment of autonomic function and skin biopsy for EM imaging of small fibers in a subset (n=19). Six of 28 pts (21%) so far have developed PN with most being G2: 1 pt experienced G3 PN and drug was discontinued. Dose modification was required in 4 pts and supplements have been used in all pts with PN. Preliminary results of neurological testing and NCS have indicated subclinical PN at baseline prior to therapy in 6/19 (30%) of pts evaluated by NCS, with small fiber, axonal PN documented in 1 pt with treatment-emergent PN. Bortezomib-related toxicity has otherwise been manageable. Conclusion: Single agent bortezomib is a promising approach for newly diagnosed pts and is without the complications of high-dose dex. The incidence of subclinical PN by NCS at baseline prior to therapy is currently 30%; G2 or greater treatment-emergent PN has occurred in 21% of pts and was G3 in only 1 pt (4%) to date. Further assessment of PN including analysis of skin biopsies is ongoing.

Recent understanding of MM biology suggests that MM cells rely on their microenvironment for disease progression and dissemination. MM cell interaction with stromal cells in the bone marrow microenvironment fosters chemotherapy resistance. Targeting the microenvironment with novel biologic agents such as thalidomide (T) has shown encouraging clinical results in patients with previously untreated as well as relapsed/refractory MM. We have previously shown here that VAD plus low dose T (t) is an effective salvage regimen for VAD refractory pts. We report the preliminary results of an ongoing phase II trial studying a combined chemoimmunotherapeutic approach - standard VAD plus t (200 mg) in treatment-naïve MM pts. This regimen was designed to target concurrently the malignant cell and its microenvironment. MM pts, ≥ Stage I with no prior therapy were eligible for study. Monthly infusional VAD (standard dose) was given for 4 cycles every 28 days concurrently with t for 4 months. t (100mg) was started 1 wk prior to VAD and was escalated in 1–2 wks to 200mg. Pts were evaluated for response after each cycle and after cycle 4 using SWOG criteria. Pts characteristics include: enrolled n=16, 8M, 8F; median age 58 yrs range 46–77; Stage III disease n=11, Stage II, n=3 and Stage 1, n=1; and Median B2M, 1.9 mg/L (range 1.2–11.5). Low dose coumadin (1–2 mg) was used for venous thromboembolism (VTE) prophylaxis, t was also held during the 4 days of each infusion of VAD. All pts are evaluable for toxicity and 11 are evaluable for response after completing 4 cyc. 10/11 (91%) responded clinically; CR, n=3, PR, n=7. One pt had progressive disease. Three pts with responding disease were removed from study for Grade III toxicity (1 adriamycin associated cardiomyopathy, 1 pulmonary hypertension and 1 recurrent infections) but are not included in response evaluation. Toxicities: fatigue (Gr. II) was the most common side effect (25%) and DVT was noted in 2 (12%). All pts eligible for stem cell (SC) transplant (n=7), were able to collect adequate amount of SC post VAD-t. Preliminary results of this study suggest that VAD-t is an effective and well-tolerated regimen with improved ORR compared to standard VAD regimen in pts with treatment naïve MM. No increase in incidence of VTE was noted with the combination. Adequate SC collection was achieved in transplant eligible pts. Accrual is ongoing on this study and updated results will be presented at the annual meeting.