Spyre Therapeutics (SYRE) Jefferies 2024 Global Healthcare Conference summary

Program updates and clinical development plans

• Three parallel programs (α4β7, TL1A, IL-23) are advancing, with first clinical dosing for α4β7 expected by end of month and data by year-end.

• Regulatory clearance for α4β7 was recently obtained, enabling imminent clinical entry.

• Phase I readouts for all three programs are expected over the next 12+ months, staggered by about a quarter each.

• Combination and monotherapy arms will be developed in parallel in phase II to compare efficacy and safety directly.

• The decision to advance combinations will depend on additive efficacy and absence of overlapping toxicity.

Competitive landscape and differentiation

• TL1A antibodies in development differ in potency, half-life, and dosing frequency; the new candidate aims to combine high potency, low ADA, and extended half-life for quarterly dosing.

• Competitors' TL1A molecules have half-lives ranging from 7–19 days, with varying dosing intervals; the new candidate targets longer intervals with higher potency.

• High potency allows for lower drug load, potentially reducing off-target safety risks compared to competitors.

• Biomarker-driven strategies are being explored, but current large trials (e.g., Merck) are not fully committed to biomarker selection.

• Efficacy in all-comer populations is strong, but true first-line adoption may require doubling efficacy, as seen in the VEGA study.

Combination strategy and safety considerations

• Scientific advisors favor α4β7 and IL-23 as the safest and most predictable combination due to extensive clinical experience and orthogonal biology.

• TL1A remains a promising but less established combination partner due to less long-term safety data.

• Combination development will require demonstration of superiority over monotherapies and careful monitoring for overlapping toxicity.

• No observed adverse effects at highest tested doses for α4β7 suggest low risk of overlapping toxicity in combinations.

• Extended half-life antibodies may enable quarterly dosing, improving convenience over current regimens.