Q1: Ph1 HV SAD/MAD Initiated For SEP-479 – Ph2b In CSU Starting H2:26

Research evidence excerpt

Q1: Ph1 HV SAD/MAD Initiated For SEP-479 – Ph2b In CSU Starting H2:26

Biotechnology

Septerna

TD SECURITIES (USA) LLC EARNINGS UPDATE

May 11, 2026

Price: $23.57 (05/11/2026) Q1: Ph1 HV SAD/MAD Initiated For SEP-479 –

Price Target: NA Ph2b In CSU Starting H2:26

BUY (1)

ESG SCORE: 58/100

Yaron Werber, M.D. THE TD COWEN INSIGHT

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Q1 revs of $27M from NVO collaboration. Ph1 HV SAD/MAD for SEP-479 (PTH1R) initiated in

yaron.werber@tdsecurities.com

April w/data in late '26/early '27. Compelling Ph1 PoC for SEP-631 (MRGPRX2 NAM) showing

Sarah Cai, Ph.D. robust, dose-dependent wheal suppression w/QD oral dosing supports Ph2b CSU start in

646 562 1447 H2:26. $522M cash runway into 2029. We continue to like the platform, pipeline, and stock at

sarah.cai@tdsecurities.com

these levels.

Jaena Han, Ph.D.

646 562 1428 Our Take: SEP-479 Ph1 HV SAD/MAD Study Initiated, Data In Late '26/Early '27 – SEP-631

jaena.han@tdsecurities.com Delivers Strong POC In HV, Ph2b CSU Study Planned For H2:26

Steven Ionov, Ph.D. In April ’26, SEP-479 initiated its Ph1 SAD/MAD study in healthy volunteers (HV) with data

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expected in late '26/early '27. 'SEP-479 is a potent and selective oral small molecule PTH1R

steven.ionov@tdsecurities.com

agonist for hypoparathyroidism (HP). We also view the Ph1 data for SEP-631 (MRGPRX2 NAM)

Key Data as offering a clear clinical proof-of-mechanism and meaningful validation of Septerna’s Native

Symbol NASDAQ: SEPN Complex Platform. SEP-631 demonstrated potent, dose-dependent inhibition of icatibant-

Beta: 2.20 induced wheal formation and a placebo-like safety profile and PK supportive of once-daily

52-Week Range: $30.86-$6.73 oral dosing without food restrictions (note on AAAAI data here). The Ph2b study is initiating