On February 12, 2019, the US Food and Drug Administration (FDA) granted approval for daratumumab (Darzalex; Janssen), a CD38-directed antibody, to be given in a split-dosing regimen to patients with multiple myeloma (MM). Darzalex is the first and only CD38-directed antibody to receive regulatory approval for the treatment of patients with MM and is the first to be approved for the split-dosing regimen. This new regimen gives patients and healthcare providers the option to split the first dose of Darzalex over the course of 2 consecutive days, which has the benefit of shortening the duration of the first infusion.
“We are pleased that, with this change, patients in the U.S. receiving their first infusion of Darzalex may now have this more flexible dosing options,” stated Jan van de Winkel, chief executive officer of Janssen’s Copenhagen, Denmark–based research partner, Genmab A/S. The US approval follows approvals in December 2018 in the European Union and Canada for the daratumumab initial infusion split-dosing regimen.
The FDA approval of the split-dosing regimen is based on data from the global, multiarm, phase 1b EQUULEUS (MMY1001) clinical trial, which evaluated Darzalex in combination with various treatment regimens in patients with MM. The study investigators reported that, regardless of whether the first dose of Darzalex was administered as a split infusion or as a single infusion, pharmacokinetic concentrations were comparable at the end of weekly dosing; they also observed a similar rate and pattern of infusion reactions.
The safety profile of Darzalex was comparable when administered initially as a split or single dose, and no new safety events were observed with a split first dose. The most frequently reported adverse reactions (incidence ≥20%) in clinical trials were infusion reactions, neutropenia, thrombocytopenia, fatigue, nausea, diarrhea, constipation, vomiting, muscle spasms, arthralgia, back pain, pyrexia, chills, dizziness, insomnia, cough, dyspnea, peripheral edema, peripheral sensory neuropathy, and upper respiratory tract infection.
MM, the second most common hematologic cancer in the United States, is considered incurable, although it is manageable. Approximately 32,110 new cases of MM will be diagnosed in the United States in 2019 (18,130 in men and 13,980 in women) and approximately 12,960 deaths are expected to be attributed to the disease (6990 in men and 5970 in women).