The Food and Drug Administration has granted accelerated approval to alpelisib (Vijoice) to treat a rare genetic disorder known as PIK3CA-related overgrowth spectrum (PROS). Alpelisib, a kinase inhibitor that blocks the action of the PIK3CA gene, is approved for adults and pediatric patients ages two years and older who require systemic treatment. It is given orally daily.

PROS is a noninherited mutation of the PIK3CA gene that occurs randomly after fertilization. There are specific disorders within this spectrum and PROS signs and symptoms depend on the disorder present. For example, patients can have a larger-than-normal brain (megalencephaly); low muscle tone (hypotonia); seizures; intellectual disability; changes in the blood vessels (vascular system); and overgrowth of one area of the body (focal overgrowth) or of multiple areas of the body (segmental overgrowth), with normal growth elsewhere.

Alpelisib's efficacy was assessed in a single-arm clinical study of 37 patients with documented evidence of the gene mutation who had clinical manifestations of PROS that were determined to be severe or life-threatening. Twenty-seven percent of the patients had a radiological response at week 24; of these, 60% had a response lasting 12 months or longer. Radiological response was considered to be a 20% or greater reduction from baseline in the sum of measurable target lesion volume in up to three lesions confirmed by at least one subsequent imaging assessment.

Alpelisib's labeling includes warnings for several serious adverse effects. These include severe hypersensitivity, severe cutaneous adverse reactions, severe hyperglycemia, severe pneumonitis, severe diarrhea, and embryo-fetal toxicity. The most common adverse effects are diarrhea, stomatitis, and hyperglycemia. Drug interactions are possible with cytochrome P-450 (CYP) 3A4 inducers, CYP2C9 substrates, and breast cancer resistance protein inhibitors.

Nurses caring for patients prescribed alpelisib should read the label carefully for information on administration and dose adjustment in case of adverse effects.

For complete prescribing information for alpelisib, go to http://www.accessdata.fda.gov/drugsatfda_docs/label/2022/215039s000lbl.pdf.