Outcome of High Dose Melphalan with Autologous Hematopoietic Stem Cell Transplant In Myeloma Associated with AL Amyloidosis

Approximately 10% of patients with multiple myeloma (MM) have clinically overt primary systemic light-chain (AL) amyloidosis, and about 30% have concurrent occult AL amyloidosis. The impact of concurrent AL amyloidosis on the prognosis of myeloma is not well known. High-dose melphalan followed by autologous hematopoietic stem cell transplant (auto HCT) has shown significant activity in both MM and AL amyloidosis.

We performed a retrospective analysis of patients who had concurrent MM and AL amyloidosis and underwent auto HSCT with high dose Melphalan at MDACC between 01/1998 to 05/2010. We identified 41 patients with concurrent MM and AL amyloidosis. Patient characteristics are summarized in Table 1. Twenty -six patients had occult AL amyloid, while 15 had clinically overt disease.

Median age at auto HSCT was 56 years (39-77), 58.5% being male with median follow up of 58.7 months from the time of diagnosis and 42.5 months from auto HCT. The median time from diagnosis to auto HCT was 8.9 mos (2.7-102.4 mos). 39% had Salmon Durie Stage III disease and 36.6% had more than one involved site at the time of transplant.Cytogenetic abnormalities were detected in 24.4% of patients. Post transplant hematologic responses were as follows: ≥CR=10 (24%), ≥VGPR=16 (39%), >PR=33 (80.5%), ≥stable disease= 40 (97.6%). Among the patients with overt organ involvement, one had early death. Of the 15 evaluable patients, organ responses were scored using the published consensus guidelines for amyloidosis and were as follows: PR=5 (33.3%), ≥SD=7 (46.7%). No correlation was seen between organ response and hematologic response. The 100-day treatment related mortality (TRM) was 0 and 1-year TRM of 2.4% which is comparable to patients transplanted for MM alone at our center. The median progression-free (PFS) and overall survival (OS) from auto HCT were 33.8 and 58.3 months, respectively.The median PFS and OS from diagnosis were 49.8 and 96 mos, respectively. In multivariate analysis, creatinine ≥ 2mg/dl was associated with a shorter PFS (p=0.043) and hemoglobin <10g/dl showed a trend towards a shorter PFS (p=0.093). None of these variables (Hb <10g/dl, Age>60yrs, Creatinine≥2mg/dl, B2M >3.5mg/l, BM plasma cells>30%) emerged as significant predictors of OS. There was no significant difference in outcome between patients with occult or symptomatic AL amyloidosis for OS (p=0.24) or PFS (P=0.9)

In this analysis the outcome of patients with concurrent MM and AL amyloidosis was comparable to patients with MM alone. We believe these patients are acceptable candidates for auto HCT.

Shah: Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Millenium: Research Funding; Novartis: Research Funding. Weber: novartis-unpaid consultant: Consultancy; Merck- unpaid consultant: Consultancy; celgene- none for at least 2 years: Honoraria; millenium-none for 2 years: Honoraria; celgene, Millenium, Merck: Research Funding. Orlowski: Celgene: Consultancy, Research Funding; Millennium Pharmaceuticals, Inc.: Consultancy, Research Funding.