Will the FDA approve varegacestat in adult desmoid tumours before 31 May 2027?
deadline 2027-05-31
confidence medium
tier 4 evidence
70%Asturna estimate
Resolution criterion
Yes if the FDA approves the NDA by 31 May 2027 (Drugs@FDA or an Immunome release).
Verified starting state
NDA accepted under standard review, PDUFA date 28 April 2027. The phase 3 RINGSIDE trial showed an 84% reduction in the risk of progression or death versus placebo and an objective response rate of 56% against 9%. The gamma-secretase inhibitor class carries a history of toxicity and a competitor is already approved. (8 July 2026)
What pushes it up
- The Phase 3 RINGSIDE trial demonstrated high efficacy with an 84% reduction in the risk of progression or death [Starting State].
- The FDA has accepted the NDA with a PDUFA date of April 28, 2027, which falls before the May 31 deadline [Starting State, 2].
- The objective response rate of 56% in the trial is significantly higher than the placebo group's 9% [Starting State].
What pushes it down
- Gamma-secretase inhibitors have a documented history of toxicity, which could lead to a more cautious or prolonged FDA review [Starting State].
- The drug is under standard review rather than priority review, suggesting the FDA may not view it as a major breakthrough over the already approved competitor [Starting State].
- The PDUFA date is only one month before the deadline; any major amendment triggering a standard three-month extension would push the decision past the cutoff [Starting State].
What would move this number most
The primary uncertainty is whether the FDA will require a major amendment or additional safety data regarding the GSI class toxicity, which would likely trigger a PDUFA extension beyond the May 31, 2027 deadline.
How this number is built
| Deadline | 2027-05-31 |
| Base rate | 64% |
| Best evidence | tier 4 · 4 article(s) used |
| Independent runs | 68 · 72 (spread 4 pts) |
| Confidence | medium |
| Evidence cap | not triggered |
| Last revised | 2026-10-07 09:12 |
| Model | gemini-3-flash-preview |
Sources consulted
Probability history
2026-10-07 09:12 70% 9 article(s) on file · gemini-3-flash-preview
- What pushes it up. The Phase 3 RINGSIDE trial demonstrated high efficacy with an 84% reduction in the risk of progression or death [Starting State].
- What pushes it up. The FDA has accepted the NDA with a PDUFA date of April 28, 2027, which falls before the May 31 deadline [Starting State, 2].
- What pushes it up. The objective response rate of 56% in the trial is significantly higher than the placebo group's 9% [Starting State].
- What pushes it down. Gamma-secretase inhibitors have a documented history of toxicity, which could lead to a more cautious or prolonged FDA review [Starting State].
- What pushes it down. The drug is under standard review rather than priority review, suggesting the FDA may not view it as a major breakthrough over the already approved competitor [Starting State].
- What pushes it down. The PDUFA date is only one month before the deadline; any major amendment triggering a standard three-month extension would push the decision past the cutoff [Starting State].
- What would move this number most. The primary uncertainty is whether the FDA will require a major amendment or additional safety data regarding the GSI class toxicity, which would likely trigger a PDUFA extension beyond the May 31, 2027 deadline.
2026-09-21 22:25 72% 3 article(s) on file · openai/gpt-oss-120b (Groq)
Reasons not recorded for this revision (detailed history has only been kept since recently).
2026-09-19 13:48 80% 2 article(s) on file · gemini-3.6-flash
Reasons not recorded for this revision (detailed history has only been kept since recently).