FDA approves Pepaxto for relapsed multiple myeloma
The FDA granted accelerated approval to melphalan flufenamide in combination with dexamethasone for treatment of certain patients with relapsed or refractory multiple myeloma.
The approval applies to use of the regimen for adults who received at least four prior lines of therapy, and whose disease is refractory to at least one proteasome inhibitor, one immunomodulatory agent and one CD38-directed monoclonal antibody.
Melphalan flufenamide (Pepaxto, Oncopeptides AB) is the first anticancer peptide-drug conjugate approved for treatment of multiple myeloma. It uses technology that links a peptide carrier to a cytotoxic agent, resulting in a lipophilic compound.
“While the treatment landscape for multiple myeloma has dramatically improved in recent years, once patients become resistant to existing classes of therapy they can face a very guarded prognosis,” Paul G. Richardson, MD, clinical program leader and director of clinical research at Jerome Lipper Multiple Myeloma Center at Dana-Farber Cancer Institute, as well as a HemOnc Today Editorial Board Member, said in an Oncopeptides-issued press release. “Research has shown melphalan flufenamide to be a novel and innovative therapeutic option, which is active in refractory disease and has manageable toxicity, with the convenience of being administered by infusion once a month.”
The FDA based the approval on results of the phase 2 HORIZON study, which compared IV melphalan flufenamide in combination with dexamethasone for heavily pretreated patients with poor prognoses. The multicenter, single-arm study included 157 patients with relapsed or refractory disease, 97 of whom were triple-class refractory and had received at least four prior lines of therapy.
Researchers reported a 23.7% overall response rate, with a median response duration of 4.2 months.
The most common adverse events included fatigue (55%), nausea (32%), diarrhea (27%), pyrexia (24%) and respiratory tract infection (24%). The most common laboratory abnormalities included decrease in leukocytes (99%), platelets (99%), lymphocytes (97%), neutrophils (95%) and hemoglobin (84%), as well as creatinine increase (68%).
“Based on our findings, melphalan flufenamide is an important addition to the treatment armamentarium, with the potential to meaningfully improve outcomes in an area of important unmet medical need,” said Richardson, a HORIZON study investigator.