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LIBRETTO-531

Showed that a drug built specifically for the RET mutation beats the older multi-target pills in medullary thyroid cancer, with far fewer side effects.

PFS HR 0.28 (12-month PFS 86.8% vs 65.7%); treatment failure-free survival HR 0.25; grade ≥3 adverse events 52.8% vs 76.4%. NEJM 2023. First randomised proof that RET-selective therapy should be first line.

Setting
Untreated progressive RET-mutant medullary thyroid cancer: selpercatinib vs cabozantinib or vandetanib
Phase
Phase 3
Sponsor
Eli Lilly
Registry
Headline result
PFS HR 0.28; 12-month PFS 86.8% vs 65.7%.
Reported
2023
Enrolled
291
Replication
Consistent with single-arm LIBRETTO-001 and with pralsetinib (ARROW) activity in RET-mutant MTC.

Outcomes

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In plain words
What these results mean for people, not percentages
291 people took part
Progression-free survival at 12 monthsprimarysurrogate endpoint
  • 86.8 vs 65.7 out of 100 alive without the cancer growing at 12 months with Selpercatinib compared with Cabozantinib or vandetanib; 21.1 more per 100.
  • Roughly one extra person helped for every 5 treated. That is a rough figure taken from the two percentages, not a guarantee for any one person.
  • Put another way, the treated group had about 72 percent lower chance of the event at any given time (hazard ratio 0.28).
  • This is a surrogate endpoint: it measures the cancer being controlled or absent on scans and tests, which often, but not always, translates into living longer.
  • These results apply to the people the trial enrolled: Untreated progressive RET-mutant medullary thyroid cancer: selpercatinib vs cabozantinib or vandetanib. People in a different situation may not see the same effect.
  • The trial selected people by a biomarker (RET); the result should not be assumed for people whose cancer does not have it.

Numbers are from the trial as recorded here; see the source links in the table below. This is orientation, not medical advice: ask your team how closely the trial population matches you.

291 participants enrolled.

Progression-free survival at 12 monthsprimary
HR 0.28
Selpercatinib86.8 of 100
Cabozantinib or vandetanib65.7 of 100
Source
EndpointArmnValueHR (95% CI)pSource
Progression-free survival at 12 monthsprimarySelpercatinib86.8%0.28link
Cabozantinib or vandetanib65.7%
Replication
Consistent with single-arm LIBRETTO-001 and with pralsetinib (ARROW) activity in RET-mutant MTC.

Connected

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