[Serum ALP elevation early after treatment is a predictor for response in myeloma patients treated with bortezomib].

Several studies have shown the predictive value of elevated serum alkaline phosphatase (ALP) level in multiple myeloma (MM) patients treated with bortezomib (BTZ). We assessed the relationship between changes in ALP levels during treatment and response. Thirty patients treated with BTZ in our hospital were analyzed retrospectively. Of the patients analyzed, 12 were male, median age was 62 years (42-86), and 11 had a history of prior chemotherapy. Eighteen patients were treated with BTZ alone or in combination with dexamethasone, while the others were treated with a combination regimen employing an alkylating agent. Seven patients had undergone autologous stem cell transplantation following BTZ therapy. Ten of 28 patients showed ALP elevation of 25% or more from the baseline at 3 weeks, and 14 of the 28 had this finding at 6 weeks. Four of 5 patients who had achieved VGPR or more showed ALP elevation of 25% or more at 3 weeks, and all five had this finding by 6 weeks. No patient without ALP elevation achieved VGPR or a better response. ALP elevation exceeding 25% from the baseline by day 42 is significantly associated with a treatment response better than VGPR (p=0.019). In conclusion, ALP elevation during BTZ treatment is a valuable prognostic marker.