Forte Biosciences Inc: FB102 Opportunity Across Multiple Immune Disorders Should Drive Continued Upside; Initiate at OW

Research evidence excerpt

Forte Biosciences Inc: FB102 Opportunity Across Multiple Immune Disorders Should Drive Continued Upside; Initiate at OW

fety is favorable, positioning it as a preferred option for patients with

severe vitiligo seeking to avoid the systemic risks associated with JAK inhibitors.

At the Current Valuation, Alopecia Areata is a Call Option

We assign little value to FB102 in AA, given the efficacy of JAK inhibitors and rezpeg, the

inherent difficulty of controlling the disease, and the underwhelming data observed with EQ101

(IL-2/IL-15/IL-9 antibody). Furthermore, we highlight several mechanistic and pharmacologic

challenges. First, the difficulty of achieving sufficient drug distribution into the peribulbar space

represents a meaningful barrier, particularly for larger biologics. Second, IL-15 signaling in AA is

nuanced, with evidence suggesting roles in both disease propagation and hair follicle repair.

Third, even JAK inhibitors—arguably among the most potent systemic immunosuppressive

agents—demonstrate only moderate efficacy in this setting. In addition, the 16-week primary

endpoint is likely too early to capture a meaningful treatment effect in AA, which is a relatively

slow-moving disease, making this dataset difficult to compare against other trials that assess

efficacy at ≥24–30 weeks, which further contributes to our low PoS for FB102 in AA. We currently

model peak sales of ~$1.8B (~$250M adjusted).

Main risks to thesis

The main risks to our thesis include underwhelming clinical data from FB102 in CeD relative to

ANB033, as CeD represents the majority of our FBRX valuation at ~$37/share. Key risks to our

vitiligo valuation include underwhelming clinical data for FB102 and overall competitive

dynamics including data from TEV-408.