First-of-its kind myeloma drug approved

FDA has granted accelerated approval for daratumumab (Darzalex) injection for intravenous infusion for the treatment of patients with multiple myeloma who have received at least 3 prior lines of therapy, including a proteasome inhibitor (PI) and an immunomodulatory agent, or who are double-refractory to a PI and an immunomodulatory agent.

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Manufactured by Janssen Biotech, Inc., a Janssen Pharmaceutical Company of Johnson & Johnson, Darzalex is the first human anti-CD38 monoclonal antibody (mAb) approved anywhere in the world. CD38 is a surface protein that is expressed by most, if not all, multiple myeloma cells.  

The cost for Darzalex, which is expected to be on the market by mid-January, is $5,850 per infusion. For the first full year of treatment – a total of 23 doses – the average monthly wholesale acquisition cost is $11,212.

“Once past the first two months, the monthly cost of Darzalex during the bi-weekly administration phase is comparable to other leading relapsed/refractory multiple myeloma treatments,” Scott White, president of oncology for Janssen Biotech, told FormularyWatch.

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Darzalex’s approval comes just 2 months after the Biologics License Application (BLA) was accepted for priority review by FDA in September. Darzalex received breakthrough therapy designation from FDA for this indication in May 2013.

“With Darzalex, we have a promising new immunotherapy, which has shown pronounced efficacy as a single agent with an acceptable adverse event profile. This is especially important for treating these heavily pre-treated patients in whom all of the major classes of currently available medicines have failed,” said Darzalex clinical trial investigator Paul G. Richardson, MD, clinical program leader and director of clinical research at the Jerome Lipper Multiple Myeloma Center, Dana-Farber Cancer Institute.

The drug’s approval was based on the phase 2 MMY2002 (SIRIUS) study, which showed treatment with single-agent Darzalex resulted in an overall response rate (ORR) of 29.2% in patients who received a median of 5 prior lines of therapy, including a PI and an immunomodulatory agent.

Stringent complete response (sCR) was reported in 2.8% of patients, very good partial response (VGPR) was reported in 9.4% of patients and partial response (PR) was reported in 17% of patients.

For patients who responded, the median duration of response was 7.4 months. At baseline, 97% of patients were refractory to their last line of therapy, 95% were refractory to both a PI and an immunomodulatory agent, and 77% were refractory to alkylating agents. Additional efficacy data from the phase 1/2 GEN501 monotherapy study – published in The New England Journal of Medicine in August 2015 – also support this approval.

The warnings and precautions for Darzalex include infusion reactions, interference with serological testing and interference with determination of complete response. The most frequently reported adverse reactions(incidence ≥20%)were: fatigue, nausea, back pain, pyrexia,cough and upper respiratory tract infection.

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