© ASH/Luke Franke 2018
Outside the San Diego Convention Center, site of the 2018 ASH Annual Meeting
SAN DIEGO—Emapalumab, an interferon gamma-blocking antibody, controls disease activity and has a favorable safety profile in pediatric patients with primary hemophagocytic lymphohistiocytosis (HLH), according to research presented at the 2018 ASH Annual Meeting.
Investigators believe emapalumab, which was recently approved to treat HLH in the United States, should be considered a new therapeutic option for this rare and life-threatening syndrome because of the drug’s targeted mode of action.
Multiple lines of evidence have pointed to interferon gamma as a “rational target” in HLH, and elevated levels of interferon gamma are consistently observed in patients with HLH, said Franco Locatelli, MD, of Ospedale Pediatrico Bambino Gesù in Rome, Italy.
Emapalumab binds to its target with high affinity, recognizing both free and receptor-bound interferon gamma, he added.
Dr. Locatelli described trial results with emapalumab in children with HLH during the late-breaking abstracts session at ASH (abstract LBA-6).
This phase 2/3 study (NCT01818492) included 34 children with primary HLH—7 who were treatment-naïve and 27 who had failed conventional HLH therapy.
The patients received emapalumab intravenously with concomitant dexamethasone for up to 8 weeks or extended to the point of allogeneic hematopoietic stem cell transplant if needed.
The study met its primary endpoint of overall response rate higher than 40%, Dr. Locatelli reported.
The overall response rate was 64.7% for all 34 treated patients (95% confidence interval [CI], 46% to 80%; P=0.0031) and 63% for the 27 patients who had failed prior therapy (95% CI, 42% to 81%; P=0.0134).
Response was rapid, occurring at a median of 8 days after starting emapalumab, and patients were in response for a median of 75% of days during treatment, Dr. Locatelli said.
Ninety-four percent of patients had at least one adverse event (AE), and 63% had serious AEs. Common AEs included infections (56%), hypertension (35%), infusion-related reactions (27%), and pyrexia (24%).
One patient had disseminated histoplasmosis that led to discontinuation of emapalumab but resolved with appropriate treatment.
This study was sponsored by Novimmune. Investigators provided disclosures related to Sobi, Novimmune, Rocket Pharmaceuticals, Inc., AB2Bio, Novartis, Eli Lilly, Sanofi, UCB, Pfizer, and AbbVie. Two investigators reported employment with Novimmune.