IgD multiple myeloma a descriptive report of 17 cases: survival and response to therapy.

Background: Immunoglobulin D multiple myeloma (MM) is rare and has a poorer prognosis than other MM isotypes.

Design And Methods: Seventeen patients (pts) diagnosed from 1993 to 2009 with IgD MM were selected from six institutions of Multiple Myeloma Latium-Region GIMEMA Working Group.

Results: Median age was 55 years, 14 patients had bone lesions, eight had renal impairment with estimated glomerular filtration rate (eGFR) < 50 ml/min, one serum calcium ≥ 12 mg/dl, 11 had lambda light chains, five stage III of ISS, six with chromosomal abnormalities. Six pts received conventional chemotherapy (CT): five melphalan + steroids based regimens. Eleven underwent high-doses of chemotherapy with autologous stem cell transplantation (HDT/ASCT), five single and six tandem ASCT: six received bortezomib and/or thalidomide as induction therapy and five VAD. Thalidomide maintenance was used in two pts: one in HDT/ASCT and one in CT group; bortezomib was used in one patient after HDT/ASCT. At a median follow up of 38 (range 19-60) and 50 months (range 17-148) for pts treated with CT and HDT/ASCT, respectively, the overall response rate (ORR) was 83% and 90%. In the group of patients treated with CT, median overall survival (OS) was 34 months (95% CI 15- 54 months), median progression free survival (PFS) was 18 months (95% CI 3-33 months) and median duration of response (DOR) was 7 months (95% CI 5-9 months). Median OS, PFS and DOR were not reached at the time of this analysis in the HDT/ASCT group of patients. Death was observed in 27.3% of pts treated with HDT/ASCT and in 66.7% undergone CT.

Conclusions: Despite the retrospective analysis and the small number of pts our study showed that the use of HDT/ASCT seems to improve also the prognosis of IgD MM patients. Treatment options including new drugs, before and after stem cell transplantation, may further improve the outcomes of these patients.