Structure Therapeutics Reports Positive Topline Data from Phase 2 ACCESS II Trial with Once-Daily Oral Small Molecule GLP-1 Receptor Agonist, Aleniglipron Placebo-adjusted mean weight loss of 16.3% (39 lbs) at 180 mg and

Structure Therapeutics Reports Positive Topline

Data from Phase 2 ACCESS II Trial with

Once-Daily Oral Small Molecule GLP-1 Receptor

Agonist, Aleniglipron

Placebo-adjusted mean weight loss of 16.3% (39

lbs) at 180 mg and 16.0% (37 lbs) at 240 mg

at 44 weeks with no evidence of weight loss

plateau in ACCESS II, demonstrating

highest efficacy among oral GLP-1RAs and comparable

efficacy to injectable GLP1-RAs

Continued weight loss up to 16.2% (40.5 lbs)

observed with 120 mg dose in the ACCESS Open

Label Extension (OLE) study at 56 weeks, with no evidence of weight loss plateau

Updated interim data from ACCESS OLE and Body

Composition studies continue to support

improved tolerability and low (2.0 - 3.4%) study drug discontinuations due to adverse events

with the lower 2.5 mg starting dose

End-of-Phase 2 meeting with FDA scheduled in

the second quarter of 2026;

Phase 3 initiation remains on track for 2H 2026

Company to host conference call today at 8:30

SAN FRANCISCO, March 16, 2026- Structure Therapeutics

Inc. (NASDAQ: GPCR), a clinical-stage global biopharmaceutical company developing novel oral small molecule therapeutics for metabolic

diseases, with a focus on obesity, today announced positive topline data from the ACCESS clinical program of aleniglipron for the treatment

of people living with obesity and/or overweight with at least one weight related co-morbidity. This includes 44-week data from the Phase

2 ACCESS II study and interim data from the ongoing body composition study and the ACCESS open label extension (OLE) study. Aleniglipron

is an investigational orally-available, once-daily, nonpeptide small molecule agonist of the glucagon-like-peptide-1 (GLP-1) receptor

designed to address patient needs and accessibility.

In the Phase 2 ACCESS II study, aleniglipron achieved clinically meaningful

and statistically significant placebo-adjusted mean weight loss of 16.3% (39 lbs; p<0.0001) at the 180 mg dose and 16.0% (37 lbs; p<0.0001)

at the 240 mg dose at 44 weeks. In the ACCESS OLE study, aleniglipron achieved continued weight loss from 36 weeks, up to 16.2% (40.5

lbs) with 120 mg at 56 weeks. Both studies continue to demonstrate no evidence of weight loss plateau.

Aleniglipron continues to demonstrate a tolerability profile that is

consistent with the GLP-1 receptor agonist class and a compelling safety profile with no off-target events. In ACCESS II, across all active

arms in participants who reached doses 120 mg or higher from 28 to 44 weeks, there was only one (3.7%) adverse event (AE)-related treatment

With a median follow-up of 20 weeks, the tolerability data as of the

February 20, 2026 cutoff date from the interim analyses of the OLE and the body composition studies provide further support that the use

of 2.5 mg as a lower starting dose very meaningfully reduces the rate of AE-related discontinuations during the titration phase. In the

OLE, with a median follow-up of 20 weeks, there was an overall AE-related discontinuation rate of 2%. In the body composition study, with

a median follow-up of 20 weeks, there was an overall AE-related discontinuation rate of 3.4% in the aleniglipron arm.

Together, these positive efficacy, tolerability and safety findings

continue to support the advancement of aleniglipron into Phase 3 clinical development, with initiation anticipated in the second half

"The totality of efficacy and tolerability data across the Phase

2 program continue to demonstrate clear differentiation of aleniglipron, with the highest weight loss observed for an oral GLP-1RA to

date and a safety profile appropriate for chronic use in a disease that impacts millions of people," said Raymond Stevens, Ph.D.,

CEO of Structure Therapeutics. "The consistent weight loss observed across multiple studies to date reaffirms aleniglipron's

potential to be a best-in-class oral GLP-1, with injectable-like efficacy that could become a backbone oral small molecule therapy for

"The weight-lowering data from these ACCESS studies,

without apparent plateau by Week 56, are encouraging-particularly the weight loss from baseline of up to -15.3% vs +1.1% at

180 mg in ACCESS II that hopefully will be confirmed in larger, longer-term studies," said Julio Rosenstock, MD, Chair of the

ACCESS program Steering Committee and Clinical Professor of Medicine, Univ. of Texas, Southwestern Medical Center. "In

addition, the tolerability profile of starting at a low dose of 2.5 mg and the slow titration, positions the program ready for Phase

ACCESS II Study - Evaluating higher doses up to 240 mg

ACCESS II is a randomized, double-blind, placebo-controlled, clinical

study of aleniglipron that enrolled 85 adult participants living with obesity or overweight (defined as a BMI of greater than 25 kg/m2)

with at least one weight-related comorbidity. The 44-week study was designed to evaluate two higher doses of aleniglipron. Participants

started at 5 mg of aleniglipron (or placebo) and followed a 4-week titration schedule up to target doses of 120 mg, 180 mg and 240 mg.

As reported in December 2025, at 36 weeks, each of the three dose cohorts

in the ACCESS II study met statistical significance compared to placebo. Results from the primary efficacy estimandi

at 44 weeks are as follows:

Aleniglipron demonstrated a tolerability profile consistent with the

GLP-1 receptor agonist class following repeated, once-daily dosing of up to 240 mg. As expected for the GLP-1 receptor agonist drug class,

the most common AEs were gastrointestinal (GI)-related, and the two most common AEs in the titration phase were nausea and vomiting.

Body Composition Study - Evaluating lower 2.5 mg starting dose

Structure Therapeutics is conducting a randomized, placebo-controlled

body composition study that enrolled 71 adult participants to assess the effect of aleniglipron (up to 120 mg) on body fat loss over a

40-week evaluation period. Participants in the aleniglipron treatment arm start at a 2.5 mg dose, and titrate up monthly to a target dose

Data from a pre-specified interim analysis after a median

follow-up of 20 weeks demonstrated that starting at a lower dose of 2.5 mg for the first four weeks supported a manageable

tolerability profile with meaningful improvements in AE-related discontinuations compared to what was observed at a starting

titration dose of 5 mg in the ACCESS and ACCESS II studies. Additionally, at a 2.5 mg start and after a median follow up of 20 weeks

(~ 30 mg titration step) aleniglipron showed a 6.8% weight loss.

ACCESS Open-Label Extension Study - Following randomized 36-week

period, evaluating lower 2.5mg starting dose in the placebo crossover arm and efficacy beyond 36 weeks in previously treated participants

Following the 36-week randomized controlled portion of the Phase 2b

ACCESS study, participants were provided an option to roll over into the OLE and receive aleniglipron for an additional 36 weeks. A pre-specified

interim analysis after a median follow-up of 20 weeks (a total of 56 weeks) demonstrated continuing weight loss in all dose cohorts, with

no evidence of weight loss plateau. Patients who received aleniglipron in the three active dose arms during the initial double-blind portion

were titrated to a maximum dose of 120mg during the OLE. These patients achieved continued weight loss of up to 16.2% from baseline out

Participants who received placebo in the initial double-blind portion

transitioned to aleniglipron at a starting dose of 2.5 mg and titrated monthly to a target dose of 120 mg. Initial data from this group

of participants after a median follow-up of 20 weeks are consistent with the findings from the body composition study, showing that starting

at a 2.5 mg and titrating slowly was associated with a meaningful improvement in key tolerability markers compared to what was observed

in the starting 5 mg titration dose in ACCESS and ACCESS II studies.

Aleniglipron demonstrated a compelling safety profile in more than

625 participants across all studies. Importantly, to date, there have been no cases of drug-induced liver injury, no persistent liver

enzyme elevations, and no QTc prolongation across all aleniglipron studies.

Data from ACCESS, ACCESS II, body composition, and the ACCESS OLE studies

continue to provide a strong foundation to advance aleniglipron into Phase 3 clinical development. The Company has a Type B End-of-Phase

2 meeting with the United States Food and Drug Administration (FDA) scheduled in the second quarter of 2026 to finalize the Phase 3 design,

which is currently designed with a starting titration dose of 2.5 mg with the intent to evaluate multiple doses up to 240 mg. Structure

Therapeutics anticipates initiating the Phase 3 program in the second half of 2026.

Conference Call and Webcast Information

Structure Therapeutics will host a conference call and webcast today,

March 16, 2026 at 8:30 a.m. Eastern Time. A live webcast of the call will be available on the Investor Relations page of Structure Therapeutics'

website at https://ir.structuretx.com/events-presentations/events. To access the call by phone, participants should visit this

link to receive dial-in details. The webcast will be made available for replay on Structure Therapeutics' website beginning

approximately two hours after the live event. The replay of the webcast will be available for 90 days.

About Aleniglipron and Structure Therapeutics' Oral Metabolic