SRZNW

• Surrozen is an innovator using the Wnt pathway for tissue regeneration with proprietary technologies. Focus on 2 key clinical areas: SZN-043 for severe alcoholic hepatitis and SZN-1326 for inflammatory bowel disease. • Licensed SZN-413 to Boehringer Ingelheim for retinal diseases. • SZN-043 has enrolled first patient in Phase I single ascending dose study for chronic liver disease; SZN-1326 resuming dosing at lower doses using MABEL strategy. • Discussed mechanisms of Wnt signaling, preclinical data supporting programs, patent updates, and research pipelines for cornea, lacrimal gland, etc. • Completed studies to understand transaminase elevations in clinical trials and outlined clinical program plans.

• SZN-043: Expect data from Phase I single ascending dose in chronic liver disease by year-end 2023, plan Phase Ib clinical trial in 2024 with proof-of-concept data in second half 2024. • SZN-1326: Expect data from Phase I in healthy volunteers by year-end 2023, initiate Phase Ib trial in 2024 in UC patients with proof-of-concept data in second half 2024. • Boehringer Ingelheim partnership: Expect to nominate SZN-413 candidate by year-end 2023, triggering $10M milestone. • Cash runway into second half of 2024.

No traditional product segments with revenue contribution data provided; focus on clinical programs including SZN-043 for severe alcoholic hepatitis and SZN-1326 for inflammatory bowel disease, plus partnered program with Boehringer Ingelheim for retinal diseases

• Transaminase elevations observed in SZN-1326 clinical trials were unexpected and not characterized by nonclinical data. • Uncertainty in translating preclinical data to human responses, especially regarding liver-specific effects and determining the therapeutic index.

Q: Clarification on SZN-043 study plans, change from early cirrhotic to chronic liver disease, and strategy for hepatically-impaired patients A: SZN-043 study targets chronic liver disease patients with lower FibroScan scores, primary objective is safety; no specific mitigation strategy identified yet, but damaged tissue may be more sensitive Q: Half-life of SZN-1326 and expected dosing regimens for multiple ascending dose study A: SZN-1326 half-life is ~5 days; dosing regimen not finalized, but could be every other week or less Q: Target engagement for SZN-043 and SZN-1326, dose response, and confidence in 0.5 dose for 043 A: SZN-043 confirmed target engagement via ALP elevation; 0.5 dose is in range for potential therapeutic activity; SZN-1326 will use Axin2 assay in UC patients to confirm pathway activation