Abivax: Part 2 Obefazimod Data: Reinforcing on Efficacy; Reassuring on Safety

Research evidence excerpt

Abivax: Part 2 Obefazimod Data: Reinforcing on Efficacy; Reassuring on Safety

Barclays | Abivax

mg per protocol, which is relevant when interpreting the arm‑level distribution. Importantly,

both non-NMSC cases were patients receiving placebo in Part 1 of the Phase 3 study.

No clustering of or pattern in malignancy cases are notable qualitative points

A key qualitative point from both management and KOL discussion is that the observed

malignancy events do not show an obvious pattern. There was no clustering around a specific

tumor type, no organ specific signal, and no clear relationship with increasing exposure

duration. KOLs emphasized that, when thinking about rare malignancy events, the more

concerning scenario would be a rate above background or clustering around a rare malignancy

type. That was not observed here, and the events described were heterogeneous and generally

consistent with malignancies that are common in UC or the broader population.

This is important because the central investor concern after Part 1 was not simply that

malignancies occurred, but that the imbalance might represent an emerging drug related

signal. The lack of clustering, the presence of patient‑level confounders, and the fact that rates

fall within expected background ranges appear to argue against a clear treatment-related

signal. The NMSC findings are also better contextualized after today’s update, with

management highlighting that the Phase 3 program incorporated more intensive,

protocol‑driven dermatologic surveillance (including routine lesion photography, central

dermatologist review, and adjudication), which likely increased detection rates relative to

standard UC trials, rather than reflecting a higher underlying incidence attributable to the drug.