SAN DIEGO Daratumumab plus bortezomib and dexamethasone (DVd) is superior to bortezomib plus dexamethasone (Vd) regardless of the number of prior lines of therapy, cytogenetic risk, or time since last therapy in patients with relapsed/refractory multiple myeloma, according to an updated analysis of the pivotal CASTOR study presented at the American Society of Hematology (ASH) 58th Annual Meeting and Exposition.1

Daratumumab is a first-in-class CD38-blocking monoclonal antibody that demonstrated activity in combination with bortezomib and dexamethasone in contrast with Vd alone in a pre-specified interim analysis of the phase 3 CASTOR trial of patients with relapsed/refractory multiple myeloma (hazard ratio, 0.39). The U.S. Food and Drug Administration approved the combination for this indication in November 2016.

To identify the patient population who derive the most benefit from this regimen, researchers conducted subgroup analyses with respect to prior lines of therapy and cytogenetic status after additional follow-up.

“Responses continue to deepen in the DVd group with longer follow-up,” said Maria-Victoria Mateos, MD, PhD, University Hospital of Salamanca/IBSAL, Spain.

At a median follow-up of 13.0 months, an additional 7% of patients receiving DVd achieved a complete response or better with longer follow-up.

“DVd also provides treatment benefit regardless of prior bortezomib exposure,” added Dr Mateos. “More patients achieve a deeper response with DVd after 1 prior line of treatment.”

Subgroup analyses demonstrated that the daratumumab combination improves outcomes regardless of cytogenetic risk. Dr Mateos noted that the overall survival curves are beginning to separate, but survival data are not yet mature.

No new safety signals were observed with longer follow-up.

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“Progression-free survival benefit continues to be maintained with DVd over time,” Dr Mateos concluded. “These data further support the use of this newly approved regimen of DVd in relapsed/refractory multiple myeloma, with most benefit seen in patients who have received 1 prior line of therapy.”

Reference

  1. Mateos MV, Estell J, Barreto W, et al. Efficacy of daratumumab, bortezomib, and dexamethasone versus bortezomib and dexamethasone in relapsed or refractory myeloma based on prior lines of therapy: Updated analysis of CASTOR. Paper presented at: American Society of Hematology (ASH) 58th Annual Meeting and Exposition; December 3-6, 2016; San Diego, CA.