Effectiveness of first line treatment with bortezomib prior to autologous stem cell transplantation for multiple myeloma

Background: In this retrospective study we evaluated effectiveness and safety of first- line treatment with bortezomib and dexamethasone in multiple myeloma patients, comparing our results with already published clinical studies. Methods: Patients received bortezomib as part of everyday clinical practice and according to the latest guidelines of the Zdruzenje hematologov Slovenije. Patients who were previously treated with first-line VAD (vincristine, doxorubicin modified with farmarubicine, dexamethasone), but due to uneffectiveness changed the treatment to bortezomib, were also included in the study. In 30 patients effectiveness was evaluated after average 3-4 cycles of bortezomib and dexamethasone according to the modified Southwest Oncology Group criteria. Treatment effectiveness was evaluated according to the previous VAD treatment, renal function and cytogenetic analysis. Side effects and reasons for early treatment discontinuation were described. Results: Patients received 2 to 8 cycles (median 4 cycles) of bortezomib and dexamethasone treatment. After average 3-4. cycles, 80 % of patients acheived good treatment response (56.7 % very good partial response, 23.3 % partial response). We observed that the treatment effectiveness was not influenced by previous VAD treatment, renal insufficiency and negative cytogenetic analisys, since we observed similar rates of very good partial response and partial response in patients without previous VAD treatment (82.3 % vs. 76.9 %), normal renal function (85.7 % vs. 75 % and normal cytogenetics (77.8 vs. 80 % although statistical evaluation was not possible due to small number of patients. The most common side effect was neuropathy (40 %) and in 5 patients (16.6 %), due to grade 3 or more, the treatment was discontinued. Other side effects were: anemia (26.6 %), infection (166 %), thrombocytopenia (10 %), neutropenia (6.6 %), gastrointestinal problems (23.3 %) and herpes zooster (6.6 %). Conclusions: Bortezomib (Velcade) in combination with dexamethasone is an effective and safe first-line multiple myeloma treatment and is not influenced by renal insuficience, unfavourable cytogenetic analysis or previous uneffective VAD treatment.