US regulators have approved Genentech's Gavreto (pralsetinib) for the treatment of adults with metastatic rearranged during transfection (RET) fusion-positive non-small cell lung cancer (NSCLC).

The indication was approved under the FDA's accelerated approval programme based on data from the Phase I/II ARROW study, and so continued clearance may be contingent upon verification and description of clinical benefit in a confirmatory trial.

Gavreto is a once-daily, oral precision therapy designed to selectively target RET alterations, including fusions and mutations.

According to the firm, in the Phase I/II ARROW study Gavreto produced “durable clinical responses” in people with RET fusion-positive NSCLC with or without prior therapy, and regardless of RET fusion partner or central nervous system involvement.

The drug showed an overall response rate (ORR) of 57% and complete response (CR) rate of 5.7% in the 87 people with NSCLC previously treated with platinum-based chemotherapy, and the median duration of response (DoR) was not reached.

In the 27 people with treatment-na?ve NSCLC, the ORR was 70% with an 11% CR rate.

The most common adverse reactions (≥25%) were found to be fatigue, constipation, musculoskeletal pain and hypertension.

"The FDA approval of Gavreto for RET fusion-positive non-small cell lung cancer is an important step towards our goal of providing an effective treatment option for every person diagnosed with lung cancer, no matter how rare or hard-to-treat their type of disease," said Levi Garraway, chief medical officer and head of Global Product Development.

"We remain committed to finding personalised treatment options for people with cancer based on specific genomic or molecular alterations, and we look forward to partnering with Blueprint Medicines to further explore the potential of Gavreto across multiple RET-altered tumour types."

RET-activating fusions and mutations are key disease drivers in many cancer types, including NSCLC and medullary thyroid cancer (MTC), and treatment options that selectively target these genetic alterations are limited, Genentech noted.

In NSCLC, RET fusions represent around 1-2% of patients.