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Prime Medicine Announces New Zealand Clearance of Clinical Trial Application for PM577a in H1069Q-mutated Wilson Disease

(Positive)

Prime Medicine (Nasdaq: PRME) received New Zealand Medsafe clearance for a Clinical Trial Application for PM577a, an investigational in vivo Prime Editing therapy targeting the H1069Q ATP7B mutation in Wilson Disease.

This first clinical authorization for Prime Medicine’s in vivo Prime Editing enables a global open-label Phase 1/2 trial, expected to start in the second half of 2026, with initial data anticipated in 2027.

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Positive

  • Medsafe clearance for PM577a CTA in H1069Q-mutated Wilson Disease
  • First clinical authorization for Prime Medicine’s in vivo Prime Editing therapy
  • Global open-label Phase 1/2 trial enabled by New Zealand authorization
  • Initial clinical data from PM577a program expected in 2027
  • Shared LNP platform may support additional Wilson Disease variant programs, including R778L candidate

Negative

  • PM577a remains in early-stage Phase 1/2 development with first human data only expected in 2027

News Market Reaction – PRME

+2.22%
5 alerts
+2.22% Session close to close
+2.1% Peak in 15 min
$608.68M Market Cap
0.3x Rel. Volume

In the Jun 18 session, PRME gained 2.22%, reflecting a moderate positive market reaction. Argus tracked a peak move of +2.1% during that session. Our momentum scanner triggered 5 alerts that day, indicating moderate trading interest and price volatility.

Data tracked by StockTitan Argus on the day of publication.

Market Context

This announcement marks PM577a’s cleared CTA and planned Phase 1/2 start in 2H 2026, with initial da...
Analysis

This announcement marks PM577a’s cleared CTA and planned Phase 1/2 start in 2H 2026, with initial data in 2027. Prior clinical updates showed mixed stock responses; elevated short interest remains a risk factor to monitor around future readouts.

Key Figures

Phase: Phase 1/2 Trial start timing: 2H 2026 Initial data timing: 2027 +2 more
5 metrics
Phase Phase 1/2 Design of global first-in-human PM577a trial
Trial start timing 2H 2026 Planned initiation of Phase 1/2 PM577a trial
Initial data timing 2027 Expected initial clinical proof-of-concept readout
Imaging readout 64Cu PET Non-invasive functional readout of ATP7B activity
Copper excretion metric 24-hour urinary copper excretion Planned efficacy and biological activity assessment

Previous Clinical trial Reports

2 past events · Latest: Dec 07 (Positive)
Same Type Pattern 2 events
Date Event Sentiment 24h Move Catalyst
Dec 07 Clinical data update Positive +12.6% NEJM publication and ASH presentation of PM359 Phase 1/2 CGD data.
May 19 Clinical data update Positive -16.0% Breakthrough PM359 CGD data showing rapid NADPH oxidase restoration.

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

Pattern Detected

Clinical trial news has produced mixed reactions, with one strongly positive move and one sharp selloff.

Key Terms

prime editing, clinical trial application (cta), in vivo, lnp delivery platform, +2 more
6 terms
prime editing medical
"first clinical authorization for an in vivo Prime Editing therapy from Prime Medicine"
Prime editing is a gene‑editing method that can precisely rewrite small stretches of DNA inside living cells without cutting both strands, functioning like a targeted “find-and-replace” for genetic code rather than tearing out a paragraph. It matters to investors because it expands the range of treatable genetic conditions and may reduce side effects and development risk, influencing biotech valuations, clinical prospects, intellectual property stakes and regulatory outlooks.
clinical trial application (cta) regulatory
"Medsafe has cleared the Company’s Clinical Trial Application (CTA) for PM577a"
A clinical trial application (CTA) is the formal request a company files with health regulators asking permission to begin testing a new drug or medical device in people. It matters to investors because approval is a key development milestone—like getting a building permit to start construction—signaling reduced regulatory risk, unlocking the next phase of data generation and timelines for potential commercial value, while rejection or delay can push back prospects and increase costs.
in vivo medical
"first clinical authorization for an in vivo Prime Editing therapy from Prime Medicine"
In vivo describes tests or experiments performed inside a living organism, such as an animal or human, to observe how a drug, device or biological process behaves in a real, functioning body. Investors care because in vivo results reveal safety, effectiveness and possible side effects that lab tests cannot, much like road-testing a prototype car in traffic rather than only on a bench — outcomes can strongly influence regulatory approval, clinical success and a company’s valuation.
lnp delivery platform technical
"Shared LNP delivery platform may enable rapid expansion into additional WD pathogenic variant"
A LNP delivery platform is a technology that uses tiny fat-based particles to carry and protect medicines—especially RNA and similar fragile molecules—into specific cells in the body. Think of it as a microscopic delivery truck and bubble combined: it keeps the drug safe in transit and helps it reach its target, which directly affects a therapy’s effectiveness, safety and commercial potential, making it a key driver of value and risk for investors in biotech.
64cu pet medical
"Biological activity and efficacy assessments may include copper efflux by 64Cu PET"
64Cu PET is a medical imaging technique that uses a tiny amount of the radioactive atom copper-64 attached to a molecule that homes in on specific tissues, and a PET scanner to produce detailed pictures of where that molecule accumulates in the body. Investors care because these images can show whether a drug reaches its target, help diagnose disease earlier, or support regulatory approval and commercial use of diagnostic tests—similar to using a glowing dye to reveal hidden problems inside a machine.
hepatic copper by biopsy medical
"24-hour urinary copper excretion, and hepatic copper by biopsy"
Measurement of copper in a small sample of liver tissue removed with a biopsy, reported as the amount of copper per weight of tissue. Like testing soil to see how much metal is present, this test shows whether copper has built up abnormally in the liver, which can confirm or track disorders of copper metabolism. Investors watch it because results can drive clinical decisions, affect drug development, trial outcomes, regulatory approval and market prospects for related therapies.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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-- First clinical authorization for an in vivo Prime Editing therapy from Prime Medicine --

-- PM577a targets the H1069Q mutation in the ATP7B gene, the most prevalent WD-causing allele in North America and Europe --

-- Initiation of Phase 1/2 clinical trial expected in second half of 2026; initial clinical data expected in 2027 --

-- Shared LNP delivery platform may enable rapid expansion into additional WD pathogenic variant populations; most advanced follow-on candidate targets the R778L mutation frequently found in East Asian populations --

CAMBRIDGE, Mass., June 18, 2026 (GLOBE NEWSWIRE) -- Prime Medicine, Inc. (Nasdaq: PRME), a biotechnology company committed to delivering a new class of differentiated one-time curative genetic therapies, today announced that the New Zealand Medicines and Medical Devices Safety Authority (Medsafe) has cleared the Company’s Clinical Trial Application (CTA) for PM577a, an investigational Prime Editor for Wilson Disease (WD). The clearance represents the first clinical authorization for an in vivo Prime Editing therapy from Prime Medicine and enables the initiation of the Company’s global Phase 1/2 study.

“This is a defining moment for Prime Medicine and, we hope, for the global Wilson Disease community,” said Allan Reine, M.D., Chief Executive Officer of Prime Medicine. “Wilson Disease is a well-characterized, serious genetic disorder with no approved curative option, and a standard of care burdened by low adherence, significant side effects, and lifelong dependency. With PM577a, we have the potential to offer patients a one-time therapy that precisely corrects the root cause of disease at the genomic level. The modular design of our platform also enables a systematic approach to addressing additional Wilson Disease mutations and underpins each of our liver-directed programs.”

Phase 1/2 Clinical Trial

The Phase 1/2 clinical trial is an open-label, global, first-in-human study designed to evaluate the safety, tolerability, biological activity, and efficacy of ascending doses of PM577a in adults and adolescents with WD. The study will initially enroll adults who are clinically stable on standard-of-care therapy. Biological activity and efficacy assessments may include copper efflux by 64Cu PET, serum ceruloplasmin, non-ceruloplasmin bound copper, 24-hour urinary copper excretion, and hepatic copper by biopsy.

“The design of our Wilson Disease clinical trial is grounded in the translational insights from our preclinical work,” said Mohammed Asmal, M.D., Ph.D., Chief Medical Officer of Prime Medicine. “The incorporation of 64Cu PET as a non-invasive functional readout of ATP7B activity is a particular strength of the program and we look forward to sharing proof-of-concept data in 2027.”

About PM577

PM577 is a family of LNP-formulated Prime Editing products designed to correct pathogenic ATP7B mutations in hepatocytes via a single intravenous infusion. Prime Medicine’s initial candidate, PM577a, targets the ATP7B H1069Q allele, which accounts for approximately 30–50% of WD-associated variants in the United States and Europe. The Company intends to develop additional products to address the majority of pathogenic variants on a global basis. Currently, a follow-on candidate is in pre-clinical development targeting R778L, the most common mutant allele in East Asian populations.

About Wilson Disease

Wilson Disease is a rare, autosomal recessive disorder of hepatic copper transport caused by loss-of-function mutations in the ATP7B gene, affecting an estimated 1 in 30,000 individuals globally. Impaired biliary excretion drives progressive copper accumulation in the liver, followed by multi-organ involvement including the brain, kidneys, and cornea. Clinical manifestations range from asymptomatic hepatomegaly to decompensated cirrhosis and acute liver failure; neuropsychiatric complications affect approximately two-thirds of patients. Current pharmacologic therapies, copper chelators and zinc salts, are non-curative, require lifelong daily dosing under strict dietary conditions, carry tolerability challenges, and are associated with high non-adherence rates. Liver transplantation remains the sole curative option but is constrained by organ availability and carries substantial procedural risk.

About Prime Medicine

Prime Medicine is a leading biotechnology company dedicated to creating and delivering the next generation of gene editing therapies to patients. The Company is deploying its proprietary Prime Editing platform, a versatile, precise and efficient gene editing technology, to develop a new class of differentiated one-time curative genetic therapies. Designed to make only the right edit at the right position within a gene while minimizing unwanted DNA modifications, Prime Editors have the potential to repair almost all types of genetic mutations and work in many different tissues, organs and cell types. Taken together, Prime Editing’s versatile gene editing capabilities could unlock opportunities across thousands of potential indications.

Prime Medicine is currently progressing a diversified portfolio of investigational therapeutic programs organized around its core areas of focus: liver, lung, and immunology and oncology. Across each core area, Prime Medicine is focused initially on a set of high value programs, each targeting a disease with well-understood biology and a clearly defined clinical development and regulatory path, and each expected to provide the foundation for expansion into additional opportunities. Over time, the Company intends to maximize Prime Editing’s broad and versatile therapeutic potential, as well as the modularity of the Prime Editing platform, to rapidly and efficiently expand beyond the diseases in its current pipeline, potentially including additional genetic diseases, immunological diseases, cancers, infectious diseases, and targeting genetic risk factors in common diseases, which collectively impact millions of people. For more information, please visit www.primemedicine.com.

© 2026 Prime Medicine, Inc. All rights reserved. PRIME MEDICINE, the Prime Medicine logos, and PASSIGE are trademarks of Prime Medicine, Inc. All other trademarks referred to herein are the property of their respective owners.

Forward Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, implied and express statements about Prime Medicine’s beliefs and expectations regarding: the potential of PM577a to correct the causative mutations of, and to cure, WD; the Phase 1/2 clinical trial of PM577a, including the anticipated timing of trial initiation in the second half of 2026 and initial clinical data in 2027; the continued development and advancement of its WD program, including the development of follow-on candidates; the modularity of the Prime Editing platform and the benefits thereof; its expectations regarding the breadth of Prime Editing technology and the implementation of its strategic plans for its business, programs, and technology; and the potential of Prime Editing as a transformative gene editing technology and its ability to unlock opportunities across thousands of potential indications.

Any forward-looking statements in this press release are based on management’s current expectations and beliefs and are subject to a number of risks, uncertainties and important factors that may cause actual events or results to differ materially from those expressed or implied by any forward-looking statements contained in this press release, including, without limitation, risks associated with: uncertainties related to Prime Medicine’s product candidates entering clinical trials; the authorization, initiation, and conduct of preclinical and IND-enabling studies and other development requirements for potential product candidates, including uncertainties related to opening INDs and obtaining regulatory approvals; risks related to the development and optimization of new technologies, the results of preclinical studies, or clinical studies not being predictive of future results in connection with future studies; the scope of protection Prime Medicine is able to establish and maintain for intellectual property rights covering its Prime Editing technology; Prime Medicine’s ability to identify and enter into future license agreements and collaborations; Prime Medicine’s expectations regarding the anticipated timeline of its cash runway and future financial performance; and general economic, industry and market conditions. These and other risks and uncertainties are described in greater detail in the section entitled “Risk Factors” in Prime Medicine’s most recent Annual Report on Form 10-K, as well as any subsequent filings with the Securities and Exchange Commission. In addition, any forward-looking statements represent Prime Medicine’s views only as of today and should not be relied upon as representing its views as of any subsequent date. Prime Medicine explicitly disclaims any obligation to update any forward-looking statements subject to any obligations under applicable law. No representations or warranties (expressed or implied) are made about the accuracy of any such forward-looking statements.

Investor and Media Contacts

Gregory Dearborn
Prime Medicine
857-209-0696
gdearborn@primemedicine.com

Hannah Deresiewicz
Precision AQ
212-362-1200
hannah.deresiewicz@precisionaq.com


FAQ

What did Prime Medicine (NASDAQ: PRME) announce about PM577a for Wilson Disease on June 18, 2026?

Prime Medicine announced New Zealand Medsafe clearance of its Clinical Trial Application for PM577a in Wilson Disease. According to Prime Medicine, this authorization is the company’s first clinical clearance for an in vivo Prime Editing therapy and enables a global Phase 1/2 study.

When will Prime Medicine’s PM577a Phase 1/2 trial for H1069Q-mutated Wilson Disease begin and report data?

The PM577a Phase 1/2 trial is expected to start in the second half of 2026. According to Prime Medicine, initial clinical data from this first-in-human study are anticipated in 2027, offering early insight into safety, biological activity, and efficacy.

What is Prime Medicine’s PM577a and which Wilson Disease mutation does it target?

PM577a is an investigational in vivo Prime Editing therapy for Wilson Disease. According to Prime Medicine, PM577a targets the H1069Q mutation in the ATP7B gene, described as the most prevalent Wilson Disease-causing allele in North America and Europe.

How is Prime Medicine designing the PM577a Phase 1/2 trial in Wilson Disease patients?

The PM577a Phase 1/2 trial is an open-label, global, first-in-human dose-escalation study. According to Prime Medicine, it will initially enroll clinically stable adults on standard-of-care therapy and assess safety, tolerability, biological activity, and efficacy using multiple copper-related biomarkers and imaging.

What biomarkers and assessments will be used in Prime Medicine’s PM577a Wilson Disease trial?

The trial may use copper efflux by 64Cu PET, serum ceruloplasmin, non-ceruloplasmin copper, urinary copper, and hepatic copper. According to Prime Medicine, incorporating 64Cu PET provides a non-invasive functional readout of ATP7B activity for evaluating PM577a’s biological effects.

Does Prime Medicine plan additional Wilson Disease programs beyond PM577a (NASDAQ: PRME)?

Yes, Prime Medicine highlights a shared LNP delivery platform that may support further Wilson Disease variant programs. According to Prime Medicine, the most advanced follow-on candidate targets the R778L mutation, which is frequently found in East Asian Wilson Disease populations.