Absci Announces First Participants Dosed in Phase 1/2a HEADLINE™ Trial of AI-Designed Antibody ABS-201™ for Androgenetic Alopecia

Rhea-AI Summary

Absci (Nasdaq: ABSI) announced dosing of the first healthy volunteers in the Phase 1/2a HEADLINE trial of ABS-201, an AI-designed anti-prolactin receptor antibody for androgenetic alopecia (AGA).

The randomized, double-blind, placebo-controlled study will enroll up to 227 participants, assess safety, tolerability, PK/PD, immunogenicity and efficacy (TAHC, TAHW, TAHD), and includes SAD (4–6 IV dose groups) and MAD (3–4 SC dose groups) stages. Interim AGA data are expected in H2 2026. Absci plans to start Phase 2 in endometriosis in Q4 2026 with an interim endometriosis readout planned for H2 2027. A KOL seminar is scheduled for Dec 11, 2025.

Positive

• First participants dosed on Dec 4, 2025
• Interim AGA data expected in H2 2026
• Phase 2 endometriosis planned for Q4 2026

Negative

• Trial enrollment capped at 227 participants
• Advancing Phase 2 depends on SAD safety/tolerability data

News Market Reaction

+11.70%

71 alerts

+11.70% News Effect

+14.5% Peak in 2 hr 49 min

+$62M Valuation Impact

$595M Market Cap

1.4x Rel. Volume

On the day this news was published, ABSI gained 11.70%, reflecting a significant positive market reaction. Argus tracked a peak move of +14.5% during that session. Our momentum scanner triggered 71 alerts that day, indicating high trading interest and price volatility. This price movement added approximately $62M to the company's valuation, bringing the market cap to $595M at that time.

Data tracked by StockTitan Argus on the day of publication.

Key Figures

HEADLINE trial size: up to 227 volunteers SAD dose groups: approximately 4–6 IV groups MAD dose groups: approximately 3–4 SC groups +3 more

6 metrics

HEADLINE trial size up to 227 volunteers Phase 1/2a ABS-201 AGA study enrollment target

SAD dose groups approximately 4–6 IV groups Single ascending dose portion for safety, PK, PD

MAD dose groups approximately 3–4 SC groups Multiple ascending dose portion in AGA volunteers

Interim AGA data H2 2026 Planned interim readout from Phase 1/2a HEADLINE trial

Phase 2 start Q4 2026 Planned initiation of ABS-201 Phase 2 in endometriosis

Endometriosis interim H2 2027 Expected interim readout from Phase 2 ABS-201 trial

Market Reality Check

Price: $2.89 Vol: Volume 3,332,679 is below...

low vol

$2.89 Last Close

Volume Volume 3,332,679 is below the 20-day average of 5,083,919 (relative volume 0.66x). low

Technical Shares at $3.84 are trading above the 200-day MA of $3.06 and about 39.34% below the 52-week high.

Peers on Argus

ABSI gained 12.78% while close peers like CGEM, INBX and ATXS showed small decli...

ABSI gained 12.78% while close peers like CGEM, INBX and ATXS showed small declines and LXRX, YMAB had modest gains, indicating a stock-specific move tied to this trial update.

Historical Context

5 past events · Latest: Dec 04 (Positive)

Pattern 5 events

Date	Event	Sentiment	Move	Catalyst
Dec 04	Trial initiation	Positive	+11.7%	First volunteers dosed in ABS-201 Phase 1/2a HEADLINE AGA trial.
Nov 12	Earnings update	Neutral	-1.4%	Q3 2025 financials and pipeline update including ABS-201 timing.
Oct 29	Earnings preview	Neutral	-0.7%	Announcement of date and call for Q3 2025 results.
Oct 27	Investor conferences	Neutral	+5.4%	Planned participation in multiple November healthcare conferences.
Oct 15	Clinical update	Positive	+28.2%	KOL seminar and accelerated start of ABS-201 Phase 1/2a AGA trial.

Pattern Detected

ABSI has shown strong positive reactions to ABS-201 AGA milestones, while earnings and conference updates have driven comparatively modest moves.

Recent Company History

Over the last few months, Absci has progressed from announcing an accelerated start of the ABS-201 Phase 1/2a AGA trial on Oct 15 to confirming first dosing on Dec 04. Earlier, Q3 2025 results on Nov 12 highlighted limited revenue but a substantial cash position and outlined the ABS-201 and ABS-101 development timelines. Investor conferences in late October provided additional visibility. Today’s news operationalizes earlier guidance by formally initiating the HEADLINE trial and confirming the development path for AGA and endometriosis.

Regulatory & Risk Context

Active S-3 Shelf · $400,000,000

Shelf Active

Active S-3 Shelf Registration 2025-08-12

$400,000,000 registered capacity

Absci has an effective Form S-3 shelf filed on Aug 12, 2025 to offer up to $400,000,000 in various securities, including up to $100,000,000 of common stock via a sales agreement with TD Securities. This provides substantial financing flexibility that could be used alongside ABS-201’s clinical development, but also represents potential future equity issuance.

Market Pulse Summary

The stock surged +11.7% in the session following this news. A strong positive reaction aligns with A...

Analysis

The stock surged +11.7% in the session following this news. A strong positive reaction aligns with ABSI’s history of outsized moves on ABS-201 milestones, such as the prior 28.21% gain on the October KOL and acceleration update and the 11.7% move on this trial-initiation headline. The new dosing confirmation and clear timelines to interim AGA and endometriosis readouts support the enthusiasm, but the presence of a $400,000,000 shelf registration highlights ongoing financing flexibility that could influence longer-term dilution dynamics.

Key Terms

androgenetic alopecia, prolactin receptor, pharmacokinetics (PK), pharmacodynamics (PD), +4 more

8 terms

androgenetic alopecia medical

"accelerated registrational trials for androgenetic alopecia (AGA) and Phase 2"

Androgenetic alopecia is a common form of hair loss characterized by gradual thinning and receding of hair, often following a predictable pattern. It results from a combination of genetic factors and hormone influences, similar to how certain plants are more susceptible to environmental stress. For investors, understanding trends in health and wellness, including conditions like this, can highlight shifts in consumer demand for related products and treatments.

prolactin receptor medical

"an investigational anti-prolactin receptor (PRLR) antibody engineered"

The prolactin receptor is a protein found on the surface of certain cells that binds to the hormone prolactin, which plays a key role in processes like milk production and immune system regulation. For investors, understanding this receptor helps illustrate how hormones influence health and development, potentially affecting industries related to healthcare, pharmaceuticals, and biotech innovation. Changes in how this receptor functions can impact medical treatments and market opportunities.

pharmacokinetics (PK) medical

"assess the safety, tolerability, immunogenicity, pharmacokinetics (PK), pharmacodynamics"

Pharmacokinetics (PK) is the study of how a drug moves through and is processed by the body over time. It tracks how quickly a drug is absorbed, how it spreads, how it is broken down, and how it exits the body—similar to following a recipe’s ingredients from start to finish. For investors, understanding pharmacokinetics helps assess a drug’s effectiveness and safety, which can influence its market potential and valuation.

pharmacodynamics (PD) medical

"tolerability, immunogenicity, pharmacokinetics (PK), pharmacodynamics (PD), and efficacy"

Pharmacodynamics (PD) is the study of how a drug affects the body and how the body's response changes with different drug doses. It explains how medications work to produce their effects, similar to how a thermostat controls room temperature. Understanding PD helps investors evaluate the potential effectiveness and risks of drugs, influencing decisions in the healthcare and pharmaceutical sectors.

single ascending dose (SAD) medical

"The single ascending dose (SAD) portion of the trial will test"

A single ascending dose (SAD) is a type of test where a new medicine is given to a small group of people in increasing amounts to see how the body responds. This process helps determine the safest and most effective dose for future use. For investors, understanding SAD studies can provide insight into a drug's development progress and potential approval prospects.

multiple ascending dose (MAD) medical

"a multiple ascending dose (MAD) portion will test approximately"

Multiple ascending dose (MAD) is a research process used to test how a new medicine affects the body when given in increasing amounts over several doses. It helps researchers find the safest and most effective dose before the drug is widely used. For investors, understanding MAD studies is important because successful results can signal progress toward new treatments and potential future profits.

randomized, double-blind, placebo-controlled medical

"HEADLINE trial in AGA is a randomized, double-blind, placebo-controlled first-in-human study"

A "randomized, double-blind, placebo-controlled" process is a method used to test the effectiveness of a new treatment or intervention. Participants are randomly assigned to different groups, with one receiving the real treatment and the other a fake version, called a placebo. Neither the participants nor the researchers know who is receiving which, which helps ensure unbiased results. For investors, this rigorous approach increases confidence that the findings are accurate and not influenced by guesswork or bias.

catagen medical

"a known driver of catagen, the regression phase of the hair cycle"

Catagen is the short, transitional phase in the hair growth cycle when a growing hair stops actively lengthening and the follicle begins to shrink before entering a resting stage. For investors, catagen matters because treatments or products that alter the length or timing of this phase can be evidence of efficacy in hair-loss or cosmetic trials, and changes here often serve as measurable signals that a drug or product is affecting biology.

AI-generated analysis. Not financial advice.

Study to evaluate safety and efficacy of novel anti-PRLR antibody; interim data anticipated in the second half of 2026

Trial design leverages operational synergies to enable accelerated registrational trials for androgenetic alopecia (AGA) and Phase 2 for endometriosis

KOL seminar scheduled for December 11 to discuss new human ex vivo data, clinical trial design, and market opportunity in AGA

VANCOUVER, Wash. and NEW YORK, Dec. 04, 2025 (GLOBE NEWSWIRE) -- Absci Corporation (Nasdaq: ABSI), a clinical-stage biopharmaceutical company advancing breakthrough therapeutics with generative AI, today announced that the first healthy volunteers have been dosed in the Phase 1/2a HEADLINE study evaluating ABS-201, an investigational anti-prolactin receptor (PRLR) antibody engineered with Absci’s generative AI platform.

The Phase 1/2a clinical trial will assess the safety, tolerability, immunogenicity, pharmacokinetics (PK), pharmacodynamics (PD), and efficacy of ABS-201. Interim data are expected in the second half of 2026.

“This milestone represents a truly exciting and transformative leap forward for regenerative biology. By advancing ABS-201 into the clinic, we are executing on our strategy to deliver a pipeline of differentiated assets,” said Sean McClain, Founder & CEO. “We believe this program highlights the massive leverage in our business model: using our AI engine to unlock high-value biological targets like PRLR, and then efficiently navigating clinical development to address significant unmet needs in both dermatology and women’s health.”

“Current treatments for androgenetic alopecia and endometriosis are often characterized by limited efficacy and significant side effects. As prolactin has been demonstrated to be a key driver for both hair loss and endometriosis, this offers us a novel pathway for treatment for these patients,” said Andreas Busch, PhD, Chief Innovation Officer at Absci. “ABS-201 represents a potential best-in-class approach, targeting the prolactin receptor with a highly specific antibody designed for superior durability and potency. We are eager to evaluate how this novel mechanism translates in the clinic, with the goal of providing a safe, effective, long-lasting solution for millions of patients who have been underserved by the standard of care for decades.”

The Phase 1/2a HEADLINE trial in AGA is a randomized, double-blind, placebo-controlled first-in-human study, enrolling up to 227 healthy volunteers with or without AGA. The primary endpoints are safety and tolerability. Secondary endpoints include PK, PD, immunogenicity, and efficacy readouts measuring target area hair count (TAHC), target area hair width (TAHW), target area darkening/pigmentation (TAHD), and patient/investigator reported outcome measures.

The single ascending dose (SAD) portion of the trial will test approximately 4-6 IV dose groups for safety, tolerability, PK and PD. Following the SAD portion of the trial, a multiple ascending dose (MAD) portion will test approximately 3-4 subcutaneous dose groups in healthy volunteers with androgenetic alopecia.

The MAD portion of this clinical trial is powered to demonstrate human proof-of-concept for the use of ABS-201 to treat androgenetic alopecia by stimulating significant hair regrowth. The company believes that this trial, if successful, will position the program for accelerated registrational trials.

“Human hair growth is tightly regulated by specific molecular signals, but our ability to intervene has been limited,” said Rodney Sinclair, MD, Professor of Dermatology at the University of Melbourne and principal investigator. “The scientific premise behind ABS-201 is compelling. It directly targets the prolactin receptor, a known driver of catagen, the regression phase of the hair cycle. Blocking prolactin signaling effectively removes the 'hand-brake' on hair growth. This approach works upstream of testosterone and DHT. It acts earlier in the balding process and before miniaturization. I believe this represents one of the most scientifically sound approaches to hair restoration I have seen.”

Absci will be hosting a virtual KOL seminar on Thursday December 11 to discuss the anticipated clinical development path, market opportunity, and differentiated profile of the ABS-201 program. The company will also disclose additional, new human ex vivo data that further supports the PRLR mechanism of action underlying this program.

In November 2025, Absci announced that the company will also be pursuing endometriosis as an additional indication for its ABS-201 anti-PRLR antibody. The Phase 1/2a clinical trial in AGA will provide safety, tolerability, and PK assessments that the company believes would enable Phase 2 clinical development in endometriosis. The company plans to initiate Phase 2 clinical development of ABS-201 in endometriosis in the fourth quarter of 2026, leveraging the insights, including safety and tolerability data, generated from the SAD portion of this Phase 1/2a AGA study. Given this synergistic development plan, Absci expects to achieve an interim readout from the Phase 2 trial in endometriosis in the second half of 2027.

About ABS-201 and Androgenetic Alopecia
Androgenetic alopecia, commonly known as male-pattern or female-pattern hair loss, affects approximately 80 million Americans. The condition causes crown balding and receding hairlines in men, and progressive hair thinning in women. Currently, the only FDA-approved treatments – minoxidil and finasteride – show limited efficacy and notable side effects, leaving patients with limited therapeutic options.

ABS-201 represents a novel therapeutic approach targeting prolactin receptors to stimulate hair follicle regeneration and promote durable hair regrowth as demonstrated in in vivo studies. In preclinical studies, the antibody demonstrated statistically significant superior hair regrowth compared to minoxidil in a preclinical mouse model. Absci anticipates an interim efficacy readout from its Phase 1/2a HEADLINE study in the second half of 2026.

About ABS-201 and Endometriosis
Endometriosis is an inflammatory disease defined by endometrial-like lesions found outside the uterine lining. Symptoms include pelvic pain, heavy bleeding, infertility, and ovarian cysts. It is a chronic, painful condition that significantly impacts the quality of life of these patients. There is currently no medical or surgical cure for this disease, which is prevalent in an estimated 5-10% of women of reproductive age worldwide, including an estimated 9 million women in the US.

ABS-201 has potential to become an efficacious and safe therapeutic treatment for endometriosis. This program is well-positioned to be best-in-class with respect to the anti-prolactin receptor mechanism based on its affinity, superior half life and bioavailability in NHPs, and high concentration formulation. Absci anticipates initiation of a Phase 2 study in endometriosis in the fourth quarter of 2026, with an interim data readout in the second half of 2027.

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 androgenetic alopecia, commonly known as male and female 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 an AI Research Lab in New York City, and Innovation Center in Switzerland. Learn more at www.absci.com or follow us on LinkedIn (@absci), X (@Abscibio) and YouTube.

Absci® standard character mark, ABS-201™, and Headline™ are trademarks and registered trademarks of Absci Corporation.

Absci 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: (i) Absci’s preclinical studies, clinical trials, as well as partnered and internally developed programs, including, without limitation, manufacturing capabilities, status of such studies and trials and expectations regarding data, safety and efficacy generally; (ii) data included in the above-described oral presentation, as well as the ability to use data from ongoing and planned clinical trials for the design and initiation of further clinical trials; (iii) Absci’s strategy, goals, anticipated financial performance and the sufficiency of its cash resources; (iv) regulatory submissions and authorizations, including timelines for and expectations regarding any anticipated regulatory agency decisions; (v) the expected benefits of its collaborations with partners; and (vi) the therapeutic value, development, and commercial potential of antibody therapies, as well as other technologies. 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 other 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.

Investor Contact:
Alex Khan
VP, Finance & Investor Relations
investors@absci.com

Media Contact:
press@absci.com
absci@methodcommunications.com

FAQ

What is Absci announcing about ABS-201 (Nasdaq: ABSI) on December 4, 2025?

Absci dosed the first healthy volunteers in the Phase 1/2a HEADLINE trial of ABS-201 for AGA.

When does Absci expect interim clinical data for ABS-201 (ABSI)?

Absci expects interim data from the AGA HEADLINE trial in H2 2026.

How many participants will the ABS-201 Phase 1/2a HEADLINE trial enroll (ABSI)?

The study will enroll up to 227 healthy volunteers with or without AGA.

What are the primary and key secondary endpoints in ABS-201 HEADLINE (ABSI)?

Primary endpoints are safety and tolerability; secondary endpoints include PK, PD, immunogenicity and efficacy metrics like TAHC, TAHW, and TAHD.

Will ABS-201 development target other indications beyond AGA (ABSI)?

Yes; Absci plans Phase 2 development in endometriosis starting in Q4 2026, leveraging Phase 1/2a safety data.

How can investors learn more about ABS-201 clinical design and data (ABSI)?

Absci will host a virtual KOL seminar on Dec 11, 2025 to discuss ex vivo data, trial design, and market opportunity.