UPDATE 1-Genentech withdraws use of Gavreto in US for a type of thyroid cancer, says partner Blueprint

(Adds details on revenue impact in paragraph 6, adds background throughout on accelerated approval)

June 30 (Reuters) - Genentech will withdraw Gavreto from use in the United States for treating a type of thyroid cancer as it was not feasible for the Roche unit to pursue the drug for full approval, its partner Blueprint Medicines said on Friday.

The move comes after the Swiss drugmaker took an over $700 million impairment related to the drug last year.

The U.S. Food and Drug Administration had granted accelerated approval to Gavreto in 2020 for treating patients aged 12 years and above with advanced or metastatic RET-mutant medullary thyroid cancer who require systemic therapy. A full approval would have required the drug to show clinical benefit in confirmatory trials.

Blueprint said Genentech decided not to pursue the late-stage study required to confirm the drug's benefits due to feasibility after consultation with the FDA.

Genentech previously said the use of the drug in the indication accounts for a fraction of its overall revenue from Gavreto in the United States, according to Blueprint.

Blueprint expects the Genentech decision to have no impact to its collaboration revenue forecast of $40 million to $50 million this year.

Gavreto was jointly developed and commercialized by Genentech and Blueprint Medicines in the U.S. through a deal in 2020. Roche, however, decided to terminate the deal with Blueprint earlier this year. The termination is effective February 2024.

Gavreto has also been granted accelerated approval in other indications like treating a type of lung cancer and another type of thyroid cancer.

The confirmatory studies required to convert accelerated approval for the drug in other indications to full approval are ongoing, according to the regulatory filing by Blueprint. (Reporting by Raghav Mahobe in Bengaluru; Editing by Dhanya Ann Thoppil and Shailesh Kuber)