FDA Grants Traditional Approval to Retevmo for RET Fusion-Positive Solid Tumors

The Food and Drug Administration (FDA) on July 14, 2026, granted traditional approval to Retevmo (selpercatinib) for adults and children 2 years of age and older with locally advanced or metastatic solid tumors that carry a RET gene fusion, as identified by an FDA-approved test.

To be eligible, patients must have seen their cancer progress on or after prior systemic treatment, or have no satisfactory alternative treatment options available.

The approval marks an upgrade from the accelerated approval Retevmo previously received for this indication — first for adult patients in 2022 and later extended to pediatric patients ages 2 and older in 2024. Traditional approval is granted when a drug's clinical benefit has been confirmed through additional clinical evidence.

What Is a RET Gene Fusion?

A RET gene fusion is a genetic alteration in which the RET gene abnormally joins with another gene, driving uncontrolled cell growth. Tumor testing — sometimes called biomarker testing or molecular profiling — can identify whether a cancer carries this change, regardless of where the cancer originated in the body.

What the Research Showed

Efficacy was evaluated in the LIBRETTO-001 trial (NCT03157128), a multicenter, open-label study. Researchers analyzed results from 75 patients with RET fusion-positive tumors other than non-small cell lung cancer (NSCLC) or thyroid cancer, who had progressed on prior treatment or had no satisfactory alternatives.

The overall response rate — the proportion of patients whose tumors shrank or disappeared — was 47%, and the median duration of response was 24.5 months.

Tumor types that responded to treatment included colorectal, pancreatic adenocarcinoma, salivary, soft tissue sarcoma, cholangiocarcinoma, carcinoma of the skin, unknown primary, breast, bronchial carcinoid, ovarian, small intestine and neuroendocrine cancers.

Data in Children and Young Adults

Efficacy in younger patients was assessed in the LIBRETTO-121 trial (NCT03899792), a multicenter, open-label study that enrolled patients with locally advanced or refractory RET fusion-positive solid tumors who were unresponsive to available therapies or had no standard curative treatment. Responses were seen in patients with congenital infantile fibrosarcoma, spindle cell sarcoma and RET fusion-positive thyroid cancer.

Dosing

For adults and adolescents 12 and older, the recommended dose of Retevmo is based on body weight:

• Less than 50 kg: 120 mg taken orally twice daily
• 50 kg or more: 160 mg taken orally twice daily

Patients should speak with their care team regarding dosing guidance for children ages 2 to 11.

Potential Side Effects

Retevmo's prescribing information includes warnings for liver toxicity, lung inflammation (interstitial lung disease/pneumonitis), high blood pressure, heart rhythm changes (QT interval prolongation), bleeding events, hypersensitivity reactions, tumor lysis syndrome, impaired wound healing and low thyroid levels (hypothyroidism). In pediatric patients, there is an additional warning for slipped capital femoral epiphysis, a hip condition. People who are pregnant or may become pregnant should discuss the risk of potential harm to a developing fetus with their care team.

Patients should talk with their oncologist about any concerns before starting treatment.

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