Phase 3 Trial of Selpercatinib in Advanced RET -Mutant Medullary Thyroid Cancer

-mutant medullary thyroid cancer in a phase 1-2 trial, but its efficacy as compared with approved multikinase inhibitors is unclear.

We conducted a phase 3, randomized trial comparing selpercatinib as first-line therapy with the physician's choice of cabozantinib or vandetanib (control group). Eligible patients had progressive disease documented within 14 months before enrollment. The primary end point in the protocol-specified interim efficacy analysis was progression-free survival, assessed by blinded independent central review. Crossover to selpercatinib was permitted among patients in the control group after disease progression. Treatment failure-free survival, assessed by blinded independent central review, was a secondary, alpha-controlled end point that was to be tested only if progression-free survival was significant. Among the other secondary end points were overall response and safety.