United Therapeutics Drug Flunks Small Cell Lung Cancer Clinical Trial

Xconomy National — 

An effort to expand use of a United Therapeutics oncology drug to the treatment of small cell lung cancer has fallen short.

United Therapeutics (NASDAQ: UTHR) announced Monday that a Phase 2/3 study testing dinutuximab (Unituxin) did not meet the main goal of helping patients live longer. The Silver Spring, MD-based company says full data from the study will be presented at upcoming scientific conferences and in peer-reviewed publications.

Dinutuximab is an antibody drug developed to bind to GD2, a molecule expressed on the surface of some cancer cells. The FDA approved the drug in 2015 as a treatment for high-risk neuroblastoma, a rare pediatric cancer that affects nerve cells still in development. In 2018, United Therapeutics reported that the drug generated $84.8 million in sales. The company has been trying to broaden its portfolio beyond pulmonary arterial hypertension products, which account for the lion’s share of its more than $1 billion in annual revenue.

United Therapeutics tested dinutuximab as a second-line treatment for small cell lung cancer patients who had relapsed or whose disease had not responded to other treatments. The Phase 2/3 study tested a combination of dinutuximab and the chemotherapy irinotecan, and compared it to treatment with either irinotecan or topetecan, another chemotherapy. In the Phase 3 portion of the study, 471 patients were randomly assigned to receive the dinutuximab combination, irinotecan, or topotecan.

United Therapeutics reported 312 deaths in the groups given dinutuximab plus irinotecan and irinotecan alone. The company said that the safety profile of the drug was consistent with earlier studies and the current drug label. That label includes a boxed warning cautioning that the drug can cause potentially life-threatening reactions, including swelling in the face and airways, breathing problems, hives, and low blood pressure. Some reactions to the drug require urgent medical intervention, including blood pressure support and bronchodilator therapy, according to the label.

Despite the clinical trial failure, United Therapeutics is pushing ahead on a different effort to expand use of dinutuximab. The company wants FDA approval of that drug—in combination with irinotecan and another chemotherapy, temozolomide—as a treatment for children whose neuroblastoma has relapsed or has not responded to earlier treatments. United Therapeutics says it plans to meet with the regulator in the first half of this year to discuss the label expansion. An application could be submitted to the FDA soon after.

Image by the National Cancer Institute