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septerna Septerna Highlights Business Progress and Reports Second Quarter 2026 Financial Results Phase 1 Clinical Trial Ongoing for SEP - 479 , an Oral Small Molecule PTHIR Agonist SEP - 479 Observed Clinical Pharmacokinetic Profile Supports Once - Daily Dosing ; SAD / MAD Data Expected in Q1 2027 Cash Position of $ 516.5 Million Expected to Support Operating Plans at Least into 2029 Exhibit 99.1 SOUTH SAN FRANCISCO , Calif . – August 10 , 2026 - Septerna , Inc. ( Nasdaq : SEPN ) , a clinical - stage biotechnology company pioneering a new era of G protein - coupled receptor ( GPCR ) drug discovery , today highlighted pipeline progress and anticipated milestones and reported financial results for the second quarter ended June 30 , 2026 . " We continue to make meaningful progress across our portfolio as we execute on our strategy to develop differentiated oral medicines targeting GPCRs , " said Jeffrey Finer , M.D. , Ph.D. , Chief Executive Officer and Co - founder of Septerna . " We are advancing our Phase 1 study of SEP - 479 and are very pleased with the observed clinical half - life , which is at the longer end of our preclinical estimates . This finding reinforces our confidence in the potential of SEP - 479 as a differentiated , once - daily oral treatment for hypoparathyroidism , and we look forward to presenting SAD / MAD data in the first quarter of 2027. We are also advancing our broader portfolio by evaluating the next phase of development for SEP - 631 in mast cell - driven diseases and progressing our TSHR program toward development candidate selection . " Recent Portfolio Progress and Anticipated Milestones • SEP - 479 PTH1R Agonist for Hypoparathyroidism : • 0 0 Septerna's Phase 1 clinical trial of SEP - 479 , a potent , selective oral small molecule PTH1R agonist for the treatment of hypoparathyroidism , is ongoing . The single - ascending dose ( SAD ) and multiple - ascending dose ( MAD ) study is evaluating safety , tolerability , pharmacokinetics and pharmacodynamics ( including serum calcium and endogenous serum PTH ) in healthy volunteers . Based on pharmacokinetic data from the ongoing Phase 1 clinical trial , the observed elimination half - life of SEP - 479 is approximately three to four days , which the Company anticipates will support once - daily dosing . To fully characterize steady - state pharmacokinetics , dosing for the MAD cohorts will be extended to 14 days . As a result , Septerna expects to report Phase 1 data from both the SAD and MAD cohorts in the first quarter of 2027 . During the quarter , the Company presented the first detailed preclinical characterization of SEP - 479 in an oral presentation at ENDO 2026 , highlighting data supporting its potential as a differentiated , once - daily oral treatment for hypoparathyroidism . SEP - 631 MRGPRX2 NAM for Mast Cell - Driven Diseases : 0 As reported in March 2026 , SEP - 631 , an oral small molecule MRGPRX2 negative allosteric modulator ( NAM ) , demonstrated positive Phase 1 clinical results , including a well - tolerated safety profile , pharmacokinetics supportive of once - daily oral dosing and robust , dose - dependent suppression of icatibant - induced skin wheal formation . 0 In lieu of a Phase 2b study in chronic spontaneous urticaria ( CSU ) , the Company is evaluating development strategies for capital - efficient , signal - finding clinical studies in mast cell - driven diseases characterized by high unmet need . TSHR NAM Program : 0 Septerna continues to progress toward development candidate selection for its TSHR NAM program , with the goal of delivering a potential disease - modifying oral treatment for Graves ' disease and thyroid eye disease . Additional Programs : 0 Septerna continues to advance and achieve research milestones from its global collaboration with Novo Nordisk to discover , develop and commercialize multiple potential oral small molecule medicines for obesity , type 2 diabetes and other cardiometabolic diseases based on specified GPCR targets . 0 The Company also continues to advance wholly - owned discovery - stage programs utilizing its Native Complex Platform across multiple therapeutic areas . Ⓡ