IBIO-600 is potentially best-in-class, long-acting anti-myostatin monoclonal antibody designed to preserve muscle and improve body composition

First-in-human study of IBIO-600 to evaluate safety, tolerability, pharmacokinetics, and pharmacodynamics in adults with obesity

SAN DIEGO, June 02, 2026 (GLOBE NEWSWIRE) -- iBio, Inc. (NASDAQ:IBIO) ("iBio" or the "Company"), a clinical-stage AI-driven innovator developing therapies for cardiometabolic and cardiopulmonary diseases and obesity, today announced the dosing of the first participant in its Phase 1 clinical trial of IBIO-600, the Company's most advanced obesity and cardiometabolic asset and its first program to enter human clinical development. This milestone marks iBio's transition to a clinical-stage biotechnology company.

IBIO-600 is a long-acting monoclonal antibody engineered for infrequent dosing and designed to target myostatin and GDF11, negative regulators of skeletal muscle growth. The investigational therapy is being developed for its potential to support muscle preservation and improve body composition during weight reduction, including in combination with GLP-1-based therapies. In non-human primates, a single administration of IBIO-600 produced a prolonged 40-to-52-day half-life, supporting the potential for extended half-life in humans. IBIO-600 also demonstrated durable body composition effects, including lean mass gains of up to 5.1% with accompanying reductions in fat mass.

The Phase 1 clinical trial is a randomized, double-blind, placebo-controlled, single ascending dose trial currently enrolling adults with overweight and obesity. The study is designed to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of IBIO-600, as well as exploratory effects on body composition. Approximately 32 individuals are expected to enroll and will be monitored for approximately nine months following administration, with study completion expected in second half of 2027. Data from the study will help inform potential future development of IBIO-600.

"This first-in-human study is an important step in evaluating IBIO-600's potential as a long-acting approach to muscle preservation during weight reduction," said Cory Schwartz, Ph.D., Vice President of Research and Early Development at iBio. "While GLP-1-based therapies have reshaped obesity treatment, the loss of lean mass during weight reduction remains an important clinical challenge. This trial is designed to establish the initial human profile of IBIO-600 and begin generating evidence of its effects on body composition, helping to inform potential future studies in combination with GLP-1-based therapies."

"The dosing of the first participant in our first clinical trial marks a defining transition for iBio as we become a clinical-stage biotechnology company," said Martin Brenner, D.V.M., Ph.D., Chief Executive Officer and Chief Scientific Officer of iBio. "Advancing our first program into human studies approximately two years after program initiation reflects the speed of our AI-driven discovery platform. With our Activin E program IBIO-610 anticipating advancing into the clinic in the first half of 2027, iBio is well-positioned to deliver a differentiated pipeline of therapies addressing significant unmet needs in cardiometabolic, cardiopulmonary and obesity care."

About iBio, Inc.

iBio (NASDAQ:IBIO) is a clinical-stage biotechnology developing long-acting antibody therapeutics for obesity, cardiometabolic and cardiopulmonary diseases, cancer, and other hard-to-treat diseases. Combining advanced antibody engineering with AI-driven discovery, iBio is advancing a differentiated pipeline designed to deliver sustained therapeutic effects and address significant unmet medical needs. iBio's mission is to transform drug discovery, accelerate development timelines, and unlock new possibilities in precision medicine.

For more information, visit www.ibioinc.com or follow iBio on LinkedIn.

FORWARD-LOOKING STATEMENTS

Certain statements in this press release constitute "forward-looking statements" within the meaning of the federal securities laws. Words such as "may," "might," "will," "should," "believe," "expect," "anticipate," "estimate," "continue," "predict," "forecast," "project," "plan," "intend" or similar expressions, or statements regarding intent, belief, or current expectations, are forward-looking statements. These forward-looking statements are based upon current estimates and assumptions and include statements regarding the potential of IBIO-600 to be a first-in class, long-acting anti-myostatin monoclonal antibody; the potential of IBIO-600 to support muscle preservation and improve body composition during weight reduction, including in combination with GLP-1-based therapies; IBIO-600 having the potential for extended half-life in humans; the 32 patients expected to enroll in the study and being monitored for approximately nine months following administration; study completion expected in second half of 2027; the potential of future development of IBIO-600; IBIO-600's potential as a long-acting approach to muscle preservation during weight reduction; the trial establishing the initial human profile of IBIO-600 and generating evidence of its effects on body composition, helping to inform potential future studies in combination with GLP-1-based therapies; advancing the Activin E program IBIO-610 into the clinic in the first half of 2027; iBio being well-positioned to deliver a differentiated pipeline of therapies addressing significant unmet needs in cardiometabolic and obesity care; iBio creating a potential pipeline of breakthrough antibody treatments to address significant unmet medical needs; and iBio's ability to transform drug discovery, accelerate development timelines, and unlock new possibilities in precision medicine. While iBio believes these forward-looking statements are reasonable, undue reliance should not be placed on any such forward-looking statements, which are based on information available to it on the date of this release. These forward-looking statements are subject to various risks and uncertainties, many of which are difficult to predict that could cause actual results to differ materially from current expectations and assumptions from those set forth or implied by any forward-looking statements. Important factors that could cause actual results to differ materially from current expectations include, among others, the ability of iBio's innovative pipeline of therapeutics in cardiometabolic and cardiopulmonary diseases and obesity to promote healthy weight loss and muscle-building; the ability of IBIO-600 to address an unmet need, particularly around the loss of muscle mass; IBIO-600, a long-acting anti-myostatin monoclonal antibody, preserving muscle and improving body composition; and IBIO-600 having the potential to be used alongside GLP-1; iBio's ability to create a potential pipeline of breakthrough antibody treatments to address significant unmet medical needs; iBio's ability to obtain regulatory approvals for commercialization of its product candidates, or to comply with ongoing regulatory requirements; regulatory limitations relating to iBio's ability to promote or commercialize its product candidates for specific indications; acceptance of iBio's product candidates in the marketplace and the successful development, marketing or sale of products; whether iBio will incur unforeseen expenses or liabilities or other market factors; and the other factors discussed in iBio's filings with the SEC including its Annual Report on Form 10-K for the year ended June 30, 2025 and its subsequent filings with the SEC on Forms 10-Q and 8-K. The information in this release is provided only as of the date of this release, and iBio undertakes no obligation to update any forward-looking statements contained in this release on account of new information, future events, or otherwise, except as required by law.

Contact:

iBio, Inc.

Investor Relations

ir@ibioinc.com

Ignacio Guerrero-Ros, Ph.D., or David Schull

Russo Partners, LLC

Ignacio.guerrero-ros@russopartnersllc.com

David.schull@russopartnersllc.com

(858) 717-2310 or (646) 942-5604

iBio Becomes a Clinical-Stage Company with First Participant Dosed in Phase 1 Clinical Trial of IBIO-600 in Adults with Obesity