TRIUMPH-1 Analyst Reaction (May 22): LLY +1% Premarket, William Blair Sees High-BMI Confinement on 11.3% Discontinuation + Dysesthesia Signal, Mahmood 'Very Impressive' Pending ADA Data
Day-after analyst reaction to Lilly's May 21 TRIUMPH-1 topline split between efficacy enthusiasm and tolerability caution. LLY shares rose roughly 1% in Thursday premarket trading. William Blair noted that retatrutide's 11.3% discontinuation rate on 12 mg plus the dysesthesia signal (skin tingling, 12.5% of 12 mg participants — a finding not reported in Phase 2 data) probably confines the drug to higher-BMI patient populations, with tirzepatide remaining the volume agent at the moderate-BMI tier. BMO Capital Markets specifically flagged the dysesthesia signal as worth monitoring in subsequent readouts and the TRIUMPH-4 follow-on detail. Manak Mahmood at Pharma Intelligence framed the data as 'very impressive' but noted ADA 2026 full data presentation in two weeks will be critical for the obesity-market positioning. The GI side-effect profile at 12 mg — nausea 42.4%, vomiting 25.3%, diarrhea 32.0% — is the tolerability gap that prescribers will weigh against the efficacy gain over tirzepatide.