COMy 2020 | Updates on the HORIZON study: melflufen in R/R multiple myeloma

Paul Richardson, MD, Dana-Farber Cancer Institute, Boston, MA, provides updates on the multicenter, international HORIZON study (NCT02963493). The study aims to determine the efficacy of a treatment regimen consisting of melflufen and dexamethasone in treating relapsed/refractory (R/R) multiple myeloma. The treatment was administrated until progression or unacceptable toxicity. 119 of the 157 patients involved in the study were triple-class refractory (CD38-directed monoclonal antibodies, proteasome inhibitors and immunomodulatory drugs). Furthermore, 55 patients suffered from extramedullary disease. The results of the trial were quite promising, especially in patients with extramedullary disease, who usually have very poor prognosis. Triple class refractory patients had a partial response rate of 26% and progression-free survival (PFS) of 8.5 months, while that of patients with extramedullary disease was 24% and 17.3 months, respectively. The clinical benefit rate in triple-class refractory patients was 39% and in patients with extramedullary disease was 31%. Furthermore, Dr Richardson elaborates on the unique mechanism of action and characteristics of melflufen, as well as treatment side-effects. The side effects were few and far between, with 5% of patients developing febrile neutropenia and 10% developing pneumonia. Moreover, treatment with melflufen did not cause alopecia or mucositis. This interview took place during the Controversies in Multiple Myeloma (COMy) 2020 Virtual World Congress.