The US Food and Drug Administration (FDA) has approved Rozlytrek (entrectinib) for adults and adolescents with tumors that test positive for NTRK gene changes, which can help cancerous tumors grow. Rozlytrek is a type of targeted therapy called a kinase inhibitor.

This is the third time the FDA has approved a drug to treat tumors with a specific genetic change rather than where the cancer was found in the body. At the same time, the FDA also approved Rozlytrek for a type of lung cancer.

The approval of Rozlytrek is another significant step in the development of cancer drugs that treat tumors based on the genetic properties of the tumor, rather than their location in the body. Last year, the FDA approved Vitrakvi (larotrectinib) for adults and children with solid tumors that test positive for NTRK gene changes. In 2017, the FDA expanded the approval of Keytruda (pembrolizumab) to include treatment for adults and children with advanced solid tumors that have either high levels of microsatellite instability (MSI-H) or mismatch repair deficiency (dMMR).

“We are in an exciting era of innovation in cancer treatment as we continue to see development in tissue agnostic therapies, which have the potential to transform cancer treatment. We’re seeing continued advances in the use of biomarkers to guide drug development and the more targeted delivery of medicine,” said FDA Acting Commissioner Ned Sharpless, MD, in a statement.

The FDA granted accelerated approval of Rozlytrek based on data from 4 clinical trials involving 54 adults with NTRK fusion-positive tumors. The most common cancer types diagnosed in these patients were lung, salivary gland, breast, thyroid, and colorectal.

All the patients were given Rozlytrek, which comes in pill form. The overall response rate, which is the portion of patients whose tumors shrank, was 57%. The improvement lasted for at least 9 months in 61% of those who responded.

The safety of Rozlytrek in children ages 12 and older was demonstrated in 30 patients under the age of 18 with NTRK-fusion-positive tumors, although they were not part of the clinical trials. The FDA says it continues to encourage the inclusion of adolescents in clinical trials.

The FDA also approved Rozlytrek for adults with advanced non-small lung cancer (NSCLC) that test positive for a change in the ROS1 gene. The approval was based on clinical studies of 51 adults with ROS1-positive NSCLC that had spread to other parts of the body. The overall response rate was 78%. The improvement lasted for at least 12 months in 55% of those who responded.

Rozlytrek was approved using several FDA approaches designed to speed up the availability of drugs to treat serious diseases: breakthrough therapy designation, priority review status, and accelerated approval. It was also granted orphan drug designation, which provides financial incentives to encourage the development of drugs for rare diseases.

Common side effects included fatigue, constipation, diarrhea, nausea and vomiting, taste changes, swelling, dizziness, painful burning or prickling sensations, muscle and joint pain, shortness of breath, thinking and memory problems, weight gain, cough, fever, and vision problems. The most serious side effects of Rozlytrek are damage to the heart and liver; central nervous system problems that may include confusion, trouble thinking, anxiety, depression, suicidal thinking, dizziness, and sleep changes; bone fractures, elevated uric acid levels in the blood, and severe vision problems. Women who are pregnant or breastfeeding should not take Rozlytrek because it may cause harm to a developing fetus or newborn baby. Women and men of reproductive age should use contraception while taking the drug.

Rozlytrek is marketed by Genentech.