Adding Johnson & Johnson/Genmab's Darzalex to the standard regimen of Takeda's Velcade and dexamethasone significantly improved outcomes for patients with recurrent or refractory multiple myeloma, show findings of a late-stage trial.

According to the data, presented at the American Society of Clinical Oncology (ASCO)'s annual meeting, the combination cut the risk of cancer progression and death by 61 percent and significantly increased the overall response rate to 83 percent from 63 percent.

The Phase III CASTOR trial was stopped early back in March after an independent data monitoring committee found that the Darzalex (daratumumab) regimen met its primary endpoint in improving progression-free survival compared to Velcade (bortezomib)/dexamethasone in patients with the incurable blood cancer.

Darzalex, which carries orphan drug status in both the EU and US, works by binding to a signalling molecule found on the surface of multiple myeloma cells called CD38 to trigger the patient's own immune system to attack the cancer cells.

"We've suspected for a long time that CD-38 is the major treatment target for multiple myeloma, but these results are unprecedented in this cancer," said lead study author Antonio Palumbo, MD, Chief of the Myeloma Unit at the Department of Oncology, University of Torino in Torino, Italy, as reported by the ASCO Post. "It's clear now that we'll be moving to a three-drug regimen with daratumumab as the standard of care."

The drug is approved in the US and EU as a monotherapy for pre-treated patients with the blood cancer; findings from CASTOR, as well as those from the POLLUX trial due shortly, will serve as the basis for potential regulatory submissions for the Darzalex combination therapy in both regions later this year, noted J&J group Janssen-Cilag.