LIBRETTO-531 Trial: Selpercatinib in Medullay Thyroid Cancer

libretto 531 trial
  • 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

Comments are closed.