United Therapeutics Receives FDA Approval for New Pediatric Cancer Therapy

United Therapeutics Receives FDA Approval for New Pediatric Cancer Therapy
March 11, 2015

The U.S. Food and Drug Administration (FDA) approved a new drug for a rare cancer that often occurs in young children.

The FDA this week approved Unituxin (dinutuximab) as part of first-line therapy for pediatric patients with high-risk neuroblastoma, a rare cancer that forms from immature nerve cells.

Neuroblastoma typically occurs in children younger than five years of age. According to the National Cancer Institute, neuroblastoma occurs in approximately one out of 100,000 children and is slightly more common in boys. There are an estimated 650 new cases of neuroblastoma diagnosed in the United States each year. Patients with high-risk neuroblastoma have a 40 to 50 percent chance of long term survival despite aggressive therapy.

Unituxin is an antibody that binds to the surface of neuroblastoma cells. Unituxin is being approved for use as part of a multimodality regimen, including surgery, chemotherapy and radiation therapy for patients who achieved at least a partial response to prior first-line multiagent, multimodality therapy.

In clinical trials including 226 pediatric patients, three years after treatment 63 percent of participants receiving the Unituxin combination were alive and free of tumor growth or recurrence, compared to 46 percent of participants treated with RA alone. In an updated analysis of survival, 73 percent of participants who received the Unituxin combination were alive compared with 58 percent of those receiving an oral retinoid drug, isotretinoin (RA), alone.

Unituxin carries a Boxed Warning alerting patients and health care professionals that Unituxin irritates nerve cells, causing severe pain that requires treatment with intravenous narcotics and can also cause nerve damage and life-threatening infusion reactions, including upper airway swelling, difficulty breathing, and low blood pressure, during or shortly following completion of the infusion. Unituxin may also cause other serious side effects including infections, eye problems, electrolyte abnormalities and bone marrow suppression.

The most common side effects of Unituxin were severe pain, fever, low platelet counts, infusion reactions, low blood pressure, low levels of salt in the blood (hyponatremia), elevated liver enzymes, anemia, vomiting, diarrhea, low potassium levels in the blood, capillary leak syndrome (which is characterized by a massive leakage of plasma and other blood components from blood vessels into neighboring body cavities and muscles), low numbers of infection-fighting white blood cells (neutropenia and lymphopenia), hives, and low blood calcium levels.

The FDA granted Unituxin priority review and orphan product designation. Priority review shortens the timeframe for review of drug applications by four months, compared to standard reviews, and is granted to drugs that, if approved, will provide a significant improvement in safety or effectiveness in the treatment of a serious condition. Orphan product designation is given to drugs intended to treat rare diseases.

With this approval, the FDA also issued a rare pediatric disease priority review voucher to United Therapeutics, which confers priority review to a subsequent drug application that would not otherwise qualify for priority review. This is the second rare pediatric disease priority review voucher granted by the FDA since inception of the rare pediatric disease review voucher program, which is designed to encourage development of new therapies for prevention and treatment of certain rare pediatric diseases.