- Year: 2023
- Title: LIBRETTO-531
- Subtitle: Phase 3 Trial of Selpercatinib in Advanced RET-Mutant Medullary Thyroid Cancer
- Trial Type: A Multicenter, Randomized, Open-label, Phase 3 Trial
Objective: To determine if the study drug selpercatinib is safer and more effective compared to standard treatment in participants with RET-mutant medullary thyroid cancer (MTC) that cannot be removed by surgery or has spread to other parts of the body.
Inclusion Criteria:
- At least 18 years of age
- Histologically or cytologically confirmed, unresectable, locally advanced and/or metastatic MTC
- No prior history of treatment with kinase inhibitors for advanced/metastatic disease
- Radiographic progressive disease
- A defined RET gene alteration identified in a tumor, DNA, or blood sample
Participants: 291 Patients
Treatment Groups:
- Selpercatinib (160 mg twice daily) – 193 patients
- Control group (Cabozantinib or Vandetanib) – 98 patients
Primary Outcome:
- 12 months Progression-free survival %
- HR, 0.28; 95% CI, 0.16-0.48 (P<0.001)
Secondary Outcomes:
- 12 months Treatment failure-free survival %: Selpercatinib 86.2, Control group 62.1
- Adverse events led to a dose reduction %: Selpercatinib 38.9, Control group 77.3
Conclusion: In patients with advanced RET-mutant medullary thyroid cancer, treatment with the RET kinase inhibitor selpercatinib resulted in significantly better progression-free survival outcomes than the multikinase inhibitors cabozantinib or vandetanib, over a median follow-up of 12 months.
Reference: Julien Hadoux et al. N Engl J Med 2023; 389:1851-1861