FDA Approves Gavreto for Advanced RET-Altered Thyroid Cancers

By Ke Zhikang

The FDA has approved Gavreto, developed by Roche and Blueprint Medicines, for the treatment of advanced or metastatic RET-mutant medullary thyroid cancer (MTC) or RET fusion-positive thyroid cancer. Gavreto initially received FDA approval in September 2020 for the treatment of non-small cell lung cancer (NSCLC) with RET gene alterations. Just three months later, it secured additional FDA approval for the treatment of thyroid cancer, positioning it to directly compete with Eli Lilly’s Retevmo, which was launched in May of this year.

Levi Garraway, Chief Medical Officer and Global Head of Product Development at Genentech, stated that the latest approval of Gavreto demonstrates its value across multiple RET-mutated tumor types, underscoring Genentech’s commitment to advancing personalized healthcare by targeting the underlying biology of each patient’s cancer.

In July 2020, Genentech and Blueprint Medicines entered into a $1.7 billion agreement aimed at developing and commercializing therapies for cancers caused by RET mutations. Blueprint Medicines and Roche agreed to co-develop Gavreto globally for the treatment of RET-mutant solid tumors, including non-small cell lung cancer (NSCLC), medullary thyroid cancer (MTC), and other thyroid cancers.

RET gene mutations/fusions are key drivers in various cancers. Papillary thyroid cancer is the most common type of thyroid cancer, with approximately 10-20% of patients having RET fusion-positive tumors, and about 90% of patients with advanced medullary thyroid cancer (MTC) carrying RET mutations. In its statement, Genentech noted that biomarker testing for RET fusions and mutations can help determine which patients are eligible for treatment with Gavreto.

Gavreto demonstrated its efficacy in the Phase 1/2 ARROW study. The drug reduced tumor size in 60% of previously treated medullary thyroid cancer patients and in 66% of treatment-naïve patients. Among patients with RET fusion-positive thyroid cancer, the drug elicited a response in 89% of cases. Gavreto’s performance in thyroid cancer was similar to that of Retevmo. In the Phase 1/2 LIBRETTO-001 study, tumor shrinkage was observed in 69% of previously treated medullary thyroid cancer patients and in 73% of treatment-naïve patients.

Retevmo’s label includes a warning about an adverse effect not present for Gavreto: an increased risk of arrhythmias due to QT interval prolongation. Another advantage of Gavreto is that it is administered orally once daily, whereas Retevmo requires twice-daily dosing.

In the third quarter of 2020, Retevmo generated $11.6 million in sales for Eli Lilly.