NEW YORK – The US Food and Drug Administration has granted accelerated approval to Eli Lilly's RET kinase inhibitor Retevmo (selpercatinib) for children 2 years of age and older who have certain RET-altered cancers.
The agency in 2020 granted accelerated approval to Retevmo as a treatment for patients 12 years old or older who have advanced RET-mutated medullary thyroid cancer requiring systemic therapy or metastatic RET fusion-positive thyroid cancer requiring systemic therapy that is also refractory to radioactive iodine. Then, in 2022, the FDA gave accelerated approval to the drug for treating adult patients who have any type of refractory solid tumor driven by RET fusions and lack other treatment options.
The FDA has now decided to expand the use of the treatment in these three settings to children as young as 2 years old after reviewing data from the LIBRETTO-121 trial. "This is the first FDA approval of a targeted therapy for pediatric patients [younger than] 12 years of age with RET alterations," the agency said in a statement.
In LIBRETTO-121, out of 25 patients with RET-altered advanced solid tumors between the ages of 2 and 20, the overall response rate was 48 percent on Retevmo as determined by a blinded independent review committee. The median duration of response was not reached, and 92 percent of patients were still responding to the treatment at one year. A portion of pediatric and young adult patients with RET-mutant medullary thyroid cancer and RET fusion-positive thyroid cancer had durable responses to Retevmo.
In the study, patients commonly experienced bone pain, diarrhea, headache, nausea, vomiting, and coronavirus infection, among other adverse reactions. The most common grade 3 and grade 4 laboratory abnormalities included decreased levels of calcium, hemoglobin, and neutrophils.
In a statement, the FDA recommended that the Retevmo dose for pediatric patients between ages 2 and 12 be based on their body surface area and the dose be based on weight for patients 12 years and older.