Abeona Therapeutics (ABEO) Clinical Development History presentation summary

Development history and dose selection

• Phase 1/2a enrolled 24 adolescents and adults; 22 completed, with symptom, histology and endoscopy improvements supporting continued development.

• Phase 2b FLUTE randomized 106 adults; all active doses met the Week 12 histologic endpoint, response was maintained through Week 52, and 3 mg HS was selected as the minimum effective daily dose.

• FLUTE safety findings included no treatment-related serious adverse events or deaths; candidiasis occurred predominantly in the 3 mg BID arm, with no major systemic corticosteroid safety signal identified.

• FLUTE established biologic and endoscopic activity, maintenance through Week 52, and acceptable long-term tolerability, supporting Phase 3 progression with 3 mg HS.

FLUTE-2 results

• Phase 3 FLUTE-2 randomized 143 adults to 3 mg HS or placebo for 12-week induction; histologic response was 64/97 vs 4/46 (OR 20.88; p<0.001).

• The dysphagia-frequency co-primary endpoint was not significant: LS mean difference -1.2 (95% CI -3.7 to 1.4; p=0.360); endoscopic responder outcomes favored treatment, including EREFS response of 50.5% vs 15.2%.

• The symptom measure was redesigned toward complete symptomatic response and a 24-week assessment, intended to allow more time for improvement to emerge.

FLUTE-3 results and symptom endpoint mapping

• FLUTE-3 randomized 218 adults for 24-week induction; histologic response was 52.8% with APT-1011 vs 4.5% with placebo (OR 22.63; p<0.001), while complete symptomatic response was 13.9% vs 12.7% (p=0.478).

• Endoscopic and fibrostenotic outcomes favored treatment; exploratory clinicopathologic response and zero-eosinophil outcomes also favored APT-1011.

• FLUTE-3 was described as well tolerated through 24 weeks, with no deaths and one treatment-emergent serious adverse event in the active arm, unrelated to study drug; OLE safety supported tolerability up to 48 weeks.

• Exploratory mapping of PROSE swallowing-difficulty NRS scores to the DSQ endpoint found a significant result at NRS≤2 (p=0.027); the presentation said DSQ use may be more likely to yield a successful future trial outcome.