The FDA has approved selpercatinib for both adults and pediatric patients who are 2 years of age and older with advanced or metastatic RET fusion-positive thyroid cancer who require systemic therapy and who are radioactive iodine-refractory.
This approval comes following the efficacy evaluated in the LIBRETTO-001 trial, a multi-center, open-label clinical trial involving 65 patients who were either refractory to radioactive iodine (RAI) treatment or had not received systemic therapy. Participants were divided into two groups: those previously treated and those naïve to systemic therapy.
The primary measures of success were the overall response rate (ORR) and the duration of response (DOR). The ORR was 85% in previously treated patients and 96% in those who were naïve to systemic therapy. The median DOR for previously treated patients was 26.7 months, while it was not yet evaluable for the systemic therapy naïve group.
Additional supportive data came from LIBRETTO-121, a study involving pediatric and young adult patients with advanced RET-altered tumors. In this cohort, the ORR was 60%, with 83% of patients maintaining a response for 12 months or more.
Common side effects reported in these studies included edema, diarrhea, fatigue, dry mouth, hypertension, abdominal pain, constipation, rash, nausea, and headache. More severe lab abnormalities included decreased lymphocytes and calcium levels, and increased liver enzymes.
These findings highlight the potential of new treatments for RET fusion-positive thyroid cancer, offering hope to patients with limited options.
References:
- https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-selpercatinib-ret-fusion-positive-thyroid-cancerÂ
Viktor Grünwald
