Will IMVT-1402 difficult-to-treat RA Ph2b topline be positive by 2027-03-31?

FcRn mechanism has no prior RA efficacy precedent — class-indication fit unvalidated. Ph2b upsizing from 120 to 170 patients sends dual signal: (1) management targeting adequate power suggests they expect positive result worth demonstrating; (2) but upsizing is specifically done when the expected effect size is marginal, which mechanically increases miss probability at clinically-meaningful thresholds. Base rate for novel-mechanism Ph2b in RA: ~45-55%. D2T population has higher placebo noise than treatment-naive RA. Strict 'clinically meaningful' resolution criterion further compresses. Net 0.45.

Coin flip reflecting genuine uncertainty. Pro: IMVT-1402 has deeper IgG reduction than batoclimab (mechanistic improvement), D2T RA has autoantibody component plausibly responsive to FcRn, Immunovant has committed to multi-indication franchise with concurrent trials suggesting internal confidence. Con: no prior RA FcRn precedent, batoclimab TED failure creates narrative bleed-through even with distinct biology, upsizing signals effect size is marginal. Strict 'clinically meaningful' framing further compresses. Net 0.50.

Conservative view. Three negatives compound: (1) FcRn mechanism has zero prior RA approvals or positive Ph3s — true mechanism-indication uncertainty; (2) batoclimab TED failure established that not all FcRn-indication combinations work, which specifically invalidates 'FcRn class works broadly' prior; (3) upsizing from 120 to 170 is a clear signal management expected marginal effect — they would not upsize a strongly-expected-winner. Strict 'clinically meaningful' criterion resolves NO for borderline hits. Base rate 40-50%.

Near coin flip with slight negative tilt. RA Ph2b base rate (all mechanisms): ~50-60%. But FcRn has no prior RA precedent, dropping applicable rate to ~45-55%. D2T population adds selection bias risk. Upsizing from 120 to 170 is concerning — management would not upsize an expected clear winner. 'Clinically meaningful' framing compresses further. Net 0.48.

Conservative tilt from batoclimab narrative compounding. Even though IMVT-1402 and batoclimab are distinct molecules with different IgG reduction profiles, and TED vs RA are different diseases, the market would treat a negative IMVT-1402 D2T RA result as class-wide re-rating evidence. Management recognizes this and would likely avoid reading out unless they have confidence, but trial design upsizing suggests borderline expected effect. Net 0.45.

Coin flip. RA Ph2b base rate 50-60% partially offset by FcRn RA novelty, batoclimab narrative, upsizing pattern. IMVT-1402 mechanistic advantage over batoclimab + severe unmet need in D2T RA + Immunovant internal commitment provide counterweight. Generous timing window (Q1 2027) minimizes timing risk. Net 0.50.

FcRn in RA is unvalidated mechanism. Ph2b upsizing to 170 signals marginal effect. D2T population adds noise. Base rate ~45-50%. Net 0.45.

Coin flip. RA Ph2b 50-60% base rate with IMVT-1402 advantages offsetting FcRn RA novelty. Net 0.50.

Slight negative tilt. FcRn RA unvalidated; upsizing signals marginal effect. Net 0.48.