What You Need to Know About the FDA's Approval of Rozlytrek

The Food and Drug Administration (FDA) approved a second targeted therapy to treat patients whose cancers have the NTRK gene fusion and for those with non-small cell lung cancer (NSCLC) whose tumors are ROS1-positive and have spread to other parts of the body.

In particular, the recommended dose of 600 mg is intended for patients aged 12 or older (based on body surface area) with the NTRK gene fusion and adults with ROS1-positive NSCLC.

Moreover, Rozlytrek’s approval is the third by the FDA for a cancer drug that treats a specific biomarker across different tumor types.

“Rozlytrek’s FDA approval for two rare types of cancer is an important advance for patients, combining a targeted medicine and genomic testing to bring this new treatment option to patients who are waiting,” Dr. Sandra Horning, Roche’s chief medical officer and head of global product development, said in a press release. “Rozlytrek is the first FDA-approved treatment that selectively targets both ROS1 and NTRK fusions, and, importantly, has also shown responses in these rare cancer types that have spread to the brain.”

Benefits of Rozlytrek

The FDA’s approval was based on data from four clinical trials of 54 adult patients with NTRK gene fusion-positive tumors — including cancers of the lung, salivary gland, breast, thyroid and colon/rectum – and one trial of 51 patients with ROS1-positive NSCLC.

Those with the NTRK gene fusion-positive tumors experienced substantial tumor shrinkage, and tumors completely disappeared in 7.4% of patients. Tumor shrinkage persisted for nine months or longer in 61% of patients with a response.

In those with ROS1-positive NSCLC, the overall response rate (those who had a complete or partial response to treatment) was 78%, and a complete response of 5.9%. Tumor shrinkage persisted for at least one year in 55% of those who responses to treatment with Rozlytrek.

Clinical investigator Dr. Robert Doebele highlighted the fact that treatment with Rozlytrek also appeared beneficial to patients with brain metastases, as it is able to penetrate the blood-brain barrier — the layer of cells that keeps your brain safe from pathogens and other toxins, but also keeps most cancer treatments out.

“Patients with cancer, especially non-small cell lung cancer, have a high risk of brain metastases and many drugs do not enter into the brain due to the blood brain barrier,” he added. “Entrectinib was designed to be brain-penetrant. It has demonstrated ability to shrink brain metastases. For patients without brain metastases, they remain at risk for developing brain metastases, and this drug may delay the onset of brain metastases.”

Moving Forward

With this approval, Doebele — who is from the University of Colorado- Denver – noted that patients must be aware of the importance of genetic testing.

“Patients should understand that they must have genetic testing of their tumor to be eligible for treatment,” he explained. “The most common way to look for ROS1 or NTRK1/2/3 gene fusions Is to have next generation sequencing of their tumor sample. Not all tests cover all genes, so a comprehensive test that covers these (and other relevant genes with targeted therapy options) should be chosen.”

Now that patients in both sub-populations have a second targeted therapy to turn to, they have much hope to look toward in the future.

“Additional targeted therapies are in development to address drug resistance that can make cancer cells no longer respond to this class of drugs,” Doebele said. “Repotrectinib (TPX-0005), a ROS1 and TRK inhibitor, and LOXO-195, a TRK inhibitor, are currently in clinical trials for this indication.”

Read CURE’s original coverage of last week’s Rozlytrek approval.