Daratumumab Monotherapy in Severe Patients with AL Amyloidosis and Biopsy-Proven Renal Involvement: A Real Life Experience

Objectives: This paper aims to describe the clinical experience with Daratumumab (DARA), a first-in-class anti-CD38 human monoclonal IgG1κ antibody monotherapy, in severe patients with AL and biopsy-proven renal involvement. Immunoglobulin light chain (AL) amyloidosis with multi-organ involvement is characterized by short survival. Novel powerful drugs are expanding the therapeutic options. Current treatment of AL amyloidosis, which has been adopted from multiple myeloma (MM), is based on chemotherapy targeting the underlying plasma cell clone. DARA is effective in treating MM. The clinical activity and toxicity profile of DARA as a single agent in the treatment of AL amyloidosis is currently under evaluation. Patients and Methods: DARA was administered in a series of patients with severe AL amyloidosis and biopsy-proven renal involvement. Five patients(mean age 64.2 years) were treated. One patient was refractory and one intolerant to conventional bortezomib-based therapy, two were treated with DARA for relapsing disease, and one was treated front-line. Results: Data showed that DARA monotherapy resulted in good clinical results, with the disappearance of M-proteins in four out of five patients and with serum free light chains (sFLC) ratio normalization in three out of four and a remarkable amelioration in the remaining patient. The four patients with still preserved renal function at baseline also showed serum creatinine stabilization or improvement and a decrease in proteinuria. These data were paralleled by the reduction of the N-terminal prohormone of brain natriuretic peptide (NT pro-BNP)values. Conclusions: Our data show that monotherapy with DARA had significant clinical efficacy in pretreated/naïve patients with severe AL amyloidosis and biopsy-proven renal involvement.