Absci Announces Preliminary Details for Phase 2 STORYLINE™ Trial of AI-Designed Antibody ABS-201™ for Endometriosis

Recruitment plans remain subject to protocol finalization and regulatory clearance; dose selection awaits HEADLINE data.

Rhea-AI Summary

Absci (ABSI) disclosed preliminary plans on September 24, 2026, for its Phase 2 STORYLINE trial of ABS-201 in endometriosis.

The planned global trial would be double-blind, randomized and placebo-controlled. It would assess the efficacy and safety of the investigational anti-prolactin receptor antibody in participants with surgically diagnosed endometriosis and moderate to severe associated pain, after a run-in period. Efficacy measures would include patient-reported reductions in menstrual pain and non-menstrual pelvic pain.

Absci anticipates recruiting approximately 150 patients from approximately 10 or more countries, subject to protocol finalization and regulatory clearance. It anticipates starting the trial in mid-2027. STORYLINE is being designed to test two or three dose levels, to be confirmed after review of safety, tolerability and pharmacokinetic data from the ongoing HEADLINE trial.

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Market Reaction – ABSI

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On Sep 24, the day this news came out, the latest delayed price for ABSI is 1.23% above the previous close. Our momentum scanner has recorded 8 alerts for this stock so far that day. The latest delayed price is $9.87.

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Market Context

On Dec 04, 2025, first dosing in the same ABS-201 HEADLINE program coincided with a 13.37% move; tha...

Analysis

On Dec 04, 2025, first dosing in the same ABS-201 HEADLINE program coincided with a 13.37% move; that earlier record marked Phase 1/2a initiation, while this announcement specified endometriosis Phase 2 design.

Key Figures

Planned enrollment: approximately 150 patients Recruitment countries: approximately 10 or more countries Anticipated trial initiation: mid-2027 +1 more

Planned enrollment

approximately 150 patients

Phase 2 endometriosis trial

Recruitment countries

approximately 10 or more countries

Phase 2 endometriosis trial

Anticipated trial initiation

mid-2027

Phase 2 endometriosis trial

Dose levels

two or three

Planned dose-ranging trial; levels subject to review of HEADLINE data

Previous Clinical trial,AI Reports

1 past event · Latest: Dec 04

Same Type 1 event

1. Dec 04

   Phase 1/2a dosing

   24h Move

   +13.4%

   Started dosing in ABS-201 HEADLINE and outlined endometriosis Phase 2 timing.

24h Move is the share-price change in the day after each event; other market factors may also have contributed.

Key Terms

pharmacokinetic, placebo-controlled, double-blind, dysmenorrhea, +1 more

5 terms

pharmacokinetic medical

"safety, tolerability, and pharmacokinetic (PK) data"

Pharmacokinetic describes how a drug moves through and leaves the body — how it is absorbed, spread to tissues, broken down and excreted — like tracking a package from pickup to delivery and disposal. For investors, these properties determine effective dose, safety risks, how often a medicine must be taken, and how reliably it works, which in turn influence clinical trial success, regulatory approval chances, production complexity and a drug’s commercial value.

placebo-controlled medical

"double-blind, randomized, placebo-controlled trial"

"Placebo-controlled" describes a testing method where one group receives the actual treatment or intervention, while another group receives a harmless, inactive version called a placebo. This approach helps determine whether the real treatment has genuine effects beyond psychological expectations. For investors, understanding this ensures confidence that reported benefits are real and not influenced by bias or false perceptions.

double-blind medical

"double-blind, randomized, placebo-controlled trial"

A double-blind process means that neither the people conducting an activity nor the people involved know certain key details, such as who is receiving a treatment or a placebo. This approach helps prevent bias from influencing the results, making the outcome more trustworthy. For investors, it ensures that decisions or judgments are based on unbiased information rather than preconceived opinions or expectations.

dysmenorrhea medical

"reductions in dysmenorrhea and non-menstrual pelvic pain"

Dysmenorrhea is painful menstrual cramping that many people experience around the start of their period; it ranges from mild discomfort to severe pain that can limit daily activities. It matters to investors because the condition drives demand for treatments, affects healthcare costs and workplace productivity, and influences markets for pharmaceuticals, medical devices, and health services—similar to how a chronic pain condition shapes demand and spending patterns.

prlr medical

"anti-prolactin receptor (PRLR) antibody"

PRLR is the gene and protein that encodes the prolactin receptor, a cell-surface protein that binds the hormone prolactin and transmits growth and survival signals into cells. It matters to investors because drugs that block or activate this receptor are a common strategy in biotech and pharma pipelines—think of the receptor as a light switch that drug developers try to turn on or off to treat conditions such as certain cancers, hormone disorders, and metabolic diseases.

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Phase 2 trial to assess efficacy and safety in participants with surgically-diagnosed endometriosis and moderate to severe endometriosis-associated pain (EAP)

Anticipated initiation of Phase 2 trial in mid-2027

VANCOUVER, Wash. and NEW YORK, Sept. 24, 2026 (GLOBE NEWSWIRE) -- Absci Corporation (Nasdaq: ABSI), a clinical-stage biopharmaceutical company advancing breakthrough therapeutics designed with generative AI, today announced additional details for the company’s planned global, multi-center Phase 2 STORYLINE clinical trial evaluating ABS-201, an investigational anti-prolactin receptor (PRLR) antibody engineered with Absci’s generative AI platform, for endometriosis.

The planned Phase 2, double-blind, randomized, placebo-controlled trial would assess efficacy and safety in participants with surgically-diagnosed endometriosis and moderate to severe endometriosis-associated pain (EAP) after a run-in period. Efficacy endpoints would include reductions in dysmenorrhea and non-menstrual pelvic pain as reported via patient-reported measures. For this trial, Absci anticipates recruiting approximately 150 patients from approximately 10 or more countries, subject to protocol finalization and regulatory clearance.

“Endometriosis affects roughly one in ten women of reproductive age, often leading to debilitating and life-altering pain. We are developing ABS-201 because we believe prolactin receptor blockade offers a fundamentally different, non-hormonal approach that may fulfill the substantial unmet clinical need facing these patients,” said Ransi Somaratne, MD, Chief Medical Officer, Head of R&D. “The initiation of this Phase 2 trial would be an important step toward establishing ABS-201’s ability to deliver durable relief of endometriosis-associated pain with a differentiated safety and tolerability profile.”

With the safety, tolerability, and pharmacokinetic (PK) data being generated for ABS-201 in the company’s ongoing HEADLINE™ trial, Absci anticipates initiation of this Phase 2 clinical trial for endometriosis in mid-2027. Absci is designing STORYLINE as a dose-ranging trial, anticipating testing two or three dose levels that will be confirmed following review of HEADLINE data.

About Absci

Absci is advancing the future of drug discovery with generative design to create better biologics for patients, faster. Our Integrated Drug Creation™ platform combines cutting-edge AI models with a synthetic biology data engine, enabling the rapid design of innovative therapeutics that address challenging therapeutic targets. Absci’s approach leverages a continuous feedback loop between advanced AI algorithms and wet lab validation. Each cycle refines our data and strengthens our models, facilitating rapid innovation and enhancing the precision of our therapeutic designs. Alongside collaborations with top pharmaceutical, biotech, tech, and academic leaders, Absci is advancing its own pipeline of AI designed therapeutics including ABS-201™, a groundbreaking innovation in hair regrowth with the potential to redefine treatment possibilities for pattern hair loss. ABS-201 is also being investigated as a potential “best-in-class” therapeutic for endometriosis, a condition with significant unmet medical need and market potential. Absci is headquartered in Vancouver, WA, with AI Research Labs in New York City and Serbia, and an Innovation Center in Switzerland. Learn more at www.absci.com or follow us on LinkedIn (@absci), X (@Abscibio) and YouTube.

Forward-Looking Statements

Statements contained in this press release regarding matters that are not historical facts are "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Such statements include, but are not limited to, statements regarding any or all of the following: the development and clinical progress of Absci's pipeline programs, including ABS-201; the design, enrollment, conduct, and timelines of our ongoing Phase 1/2a HEADLINE™ clinical trial of ABS-201 for pattern hair loss and the data being generated therefrom; the anticipated use of safety, tolerability, and pharmacokinetic data from the HEADLINE trial to inform dose selection for the STORYLINE™ clinical trial, including the anticipated testing of two or three dose levels pending review of such data; the planned design, patient enrollment targets, dosing strategy, country participation, and efficacy and safety endpoints of the Phase 2 STORYLINE trial of ABS-201 for endometriosis; the anticipated initiation of the STORYLINE trial in mid-2027, subject to regulatory clearance and protocol finalization; the potential for ABS-201 to provide efficacy in reducing endometriosis-associated pain and a differentiated safety and tolerability profile; the potential advancement of ABS-201 into Phase 3 development; the anticipated characteristics and product profile of ABS-201 as a drug product and its ability to fulfill unmet clinical need in endometriosis; and potential market opportunity and commercial prospects for ABS-201. Risks that contribute to the uncertain nature of the forward-looking statements include, without limitation, the risks and uncertainties discussed under the heading "Risk Factors" in Absci Corporation's most recent annual report on Form 10-K and in any subsequent filings made by Absci Corporation with the U.S. Securities and Exchange Commission. Existing and prospective investors are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date they are made. We disclaim any obligation or undertaking to update or revise any forward-looking statements contained in this press release, other than to the extent required by law.

Absci® standard character mark, ABS-201™, STORYLINE™, HEADLINE™, and Integrated Drug Creation™ are trademarks and registered trademarks of Absci Corporation.

Investor Contact
Alexander D.H. Khan
Corporate Vice President
Head of Investor Relations
investors@absci.com

Media Contact
press@absci.com

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

When does Absci expect to start the Phase 2 STORYLINE trial?

Absci anticipates starting the Phase 2 STORYLINE trial in mid-2027. The recruitment plan calls for approximately 150 patients from approximately 10 or more countries, subject to protocol finalization and regulatory clearance.

What pain measures will Absci use in the STORYLINE endometriosis trial?

The planned trial would assess patient-reported reductions in menstrual pain and non-menstrual pelvic pain as efficacy measures. It would also assess safety in participants with surgically diagnosed endometriosis and moderate to severe endometriosis-associated pain.