globenewswire news

- Daphne Karydas appointed as President and Chief Financial Officer

- Weston Miller, MD, appointed as Chief Medical Officer

- Additional appointments: Nina Hunter, PhD, as Chief Development Officer and Shiva G. Fritsch as Chief Corporate Affairs Officer 

- Lead program SERP-01 on track for Phase 2/3 initiation in late 2026 or early 2027

NEW YORK, Sept. 15, 2026 (GLOBE NEWSWIRE) -- Serapha Bio, Inc. (“Serapha”), a clinical-stage genetic medicines company committed to transforming the treatment of alpha-1 antitrypsin deficiency (AATD), today announced the appointment of key senior executives to its leadership team including Kenneth T. Mills as Chief Executive Officer and a member of Serapha’s Board of Directors, Daphne Karydas as President and Chief Financial Officer, Weston Miller, MD, as Chief Medical Officer, Nina Hunter, PhD, as Chief Development Officer and Shiva G. Fritsch as Chief Corporate Affairs Officer.

"We've assembled a team of proven leaders spanning genetic medicines, regulatory strategy, clinical development, manufacturing and commercialization," said Kenneth T. Mills, Chief Executive Officer of Serapha Bio. "As President and Chief Financial Officer, Daphne Karydas brings strategic and capital markets expertise, and a track record of disciplined execution, to ensure we scale this company through its next phase. Each of these leaders has helped build and operate successful biotechnology companies focused on rare and life-threatening diseases, and I'm thrilled to partner with them as we advance SERP-01, our potentially best-in-class base-editing therapy, through global clinical development."

SERP-01 is an investigational in vivo base editing therapy designed to correct the most severe disease-causing SERPINA1 E342K (PiZZ) point mutation at its source, restoring production of functional M-AAT while reducing the toxic Z isoform of alpha-1 antitrypsin (Z-AAT), with the potential to address both the liver and lung manifestations of AATD with a single intravenous administration. The U.S. Food and Drug Administration (FDA) has cleared an Investigational New Drug (IND) application for a Phase 2/3 clinical trial of SERP-01 in PiZZ AATD patients. Serapha intends to initiate this trial in late 2026 or early 2027. The FDA has also granted SERP-01 orphan drug designation and Regenerative Medicine Advanced Therapy (RMAT) designation for the treatment of PiZZ AATD.

Positive proof-of-concept data from an ongoing investigator-initiated trial (IIT), conducted through a collaboration between clinical sites in China and Germany, were presented at the European Respiratory Society (ERS) Congress earlier this month. As presented, the data showed dose-dependent increases in AAT levels above the protective threshold that were sustained through the data cutoff, substantial reductions in disease-causing Z-AAT protein, and direct correction of the target mutation at its source following a single treatment, with no bystander or off-target editing detected by the assays employed.

“What stands out is the precision of the editing profile and restoration of circulating AAT levels, which we believe give SERP-01 best-in-class potential,” continued Mr. Mills.

"The emerging data from the ongoing IIT are extremely compelling and a major driver of my conviction in joining Serapha,” said Daphne Karydas, President and Chief Financial Officer of Serapha. “That, combined with the unique opportunity to build alongside Ken and this leadership team of proven operators, is why I’m thrilled to join Serapha at this stage. With the support of world-class investors, we have the team and the runway to move SERP-01 through the clinic with the speed and rigor patients with AATD deserve.”

Serapha continues to expect its previously announced merger with Boundless Bio, Inc. (Nasdaq: BOLD) (“Boundless Bio”) to close in the fourth quarter of 2026, subject to the satisfaction of customary closing conditions, including approval by the stockholders of each company. In support of the proposed merger, Serapha has secured commitments for pre-closing private investments of approximately $230 million from a syndicate of investors co-led by RTW Investments and RA Capital Management, with participation from Janus Henderson Investors, Decheng Capital, Vivo Capital, Casdin Capital, LifeSci Venture Partners, Logos Capital, Balyasny Asset Management, and Eventide Asset Management. Of that amount, approximately $138 million has already been funded in a Series A financing and approximately $92 million is expected to be funded substantially concurrently with the closing of the merger. Following the closing, the combined company plans to operate under the name Serapha Bio and is expected to trade on Nasdaq under the ticker symbol “AATD,” subject to Nasdaq approval.

Newly Appointed Senior Leadership Team:

Kenneth T. Mills brings more than two decades of executive leadership in the biotechnology industry. He most recently served as President, Chief Executive Officer and director of Tagworks Pharmaceuticals B.V., a precision oncology company. Previously, Mr. Mills spent 15 years as the founding President and Chief Executive Officer of REGENXBIO, leading its 2015 IPO and building it into a leading gene therapy company with end-to-end research, clinical and manufacturing capabilities; he continues to serve as Chairman of its Board of Directors. He holds an SB in chemistry from the Massachusetts Institute of Technology.

Daphne Karydas brings more than two decades of financial leadership across biopharmaceutical operations, capital markets and healthcare investment banking. She most recently served as President and Chief Financial Officer of Flare Therapeutics, and previously held CFO and senior strategy roles at Syndax Pharmaceuticals and Allergan plc. Ms. Karydas serves on the boards of COMPASS Pathways, Mineralys Therapeutics and Epikast. She earned her MBA from Harvard Business School and a BA and MS in chemical engineering from MIT.

Weston Miller, MD, brings more than two decades of clinical development experience in genomic medicines for patients with rare, severe genetic disorders. He most recently served as Chief Medical Officer of Epicrispr Biotechnologies, and previously led clinical investigation at Graphite Bio and held medical director roles at Astellas Gene Therapies and Sangamo Therapeutics. Earlier in his career, Dr. Miller served as an associate professor of pediatrics at the University of Minnesota. He earned his MD from Louisiana State University School of Medicine and a BS in chemistry from Stanford University.

Nina Hunter, PhD, has close to two decades of regulatory and drug development leadership spanning industry and government. She most recently spent six years as SVP, Global Regulatory Strategy and Quality at REGENXBIO, overseeing regulatory strategy and policy and regulatory affairs from early research through BLA submission and FDA review, with additional responsibility for Quality functions. Dr. Hunter previously spent 12 years at the FDA, rising to Director of the Office of Clinical Policy and Programs. She earned her PhD in Genetics from Harvard Medical School and an AB in Biochemistry from Bowdoin College.

Shiva G. Fritsch brings more than two decades of experience guiding the growth and strategic evolution of biopharmaceutical companies. She most recently spent nine years as Chief Communications and People Officer at REGENXBIO, building its people, communications and patient advocacy functions. Ms. Fritsch previously held leadership roles at Novavax, the Howard Hughes Medical Institute and Human Genome Sciences. She earned her MBA from the University of Maryland's Robert H. Smith School of Business and a BA in Biology and Neurobiology from Bryn Mawr College.

About Serapha Bio
Serapha Bio is a clinical-stage genetic medicines company developing a proprietary base editing therapy, SERP-01, for patients with alpha-1 antitrypsin deficiency (AATD), the leading genetic cause of serious, progressive lung and liver disease. SERP-01 is in clinical development for the treatment of AATD patients with the PiZZ genotype, the most severe genetic mutation responsible for >90% of AATD cases. SERP-01 consists of a lipid nanoparticle formulation containing messenger RNA encoding Serapha’s proprietary adenine base editor together with a guide RNA. The therapy is designed to enable precise correction of the disease-causing mutation in PiZZ AATD. Correcting PiZZ, the most common gene variant associated with severe AATD, could address a large population in the U.S. and Europe. For more information, visit https://www.seraphabio.com or follow us on LinkedIn.

Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, including, but not limited to, statements regarding the proposed merger between Boundless Bio and Serapha, the expected timing and completion of the proposed merger and the related pre-closing private financings, the anticipated listing of the combined company’s common stock on Nasdaq and its expected name and ticker symbol, the anticipated contributions, experience and retention of Serapha’s newly appointed executive officers, the expected timing of initiation of the Phase 2/3 clinical trial of SERP-01, the interpretation, durability and implications of data from the ongoing investigator-initiated trial, and the potential, development plans, anticipated clinical milestones and therapeutic benefits of SERP-01, including whether SERP-01 will achieve or maintain AAT levels above the protective threshold, reduce toxic Z-AAT, correct the target mutation without bystander or off-target effects, address the liver and lung manifestations of AATD, prove to be best-in-class, or achieve regulatory approval. In addition, any statements that refer to projections, forecasts or other characterizations of future events or circumstances, including any underlying assumptions, are forward-looking statements. The words “anticipate,” “believe,” “could,” “estimate,” “expect,” “intend,” “may,” “milestone,” “on track,” “opportunity,” “plan,” “potential,” “project,” “should,” “target,” “will,” “would” and similar expressions (including the negatives of these terms or variations of them) may identify forward-looking statements, but the absence of these words does not mean that a statement is not forward-looking.

These statements are based on current expectations and are subject to risks and uncertainties that could cause actual results to differ materially, including the risk that the proposed merger or the pre-closing financings may not be completed on the anticipated terms or timing or at all; the failure to obtain the required approvals of the stockholders of Boundless Bio and Serapha; the failure to satisfy the other conditions to the closing of the proposed merger, including the effectiveness of the registration statement on Form S-4 to be filed with the SEC and approval of the Nasdaq listing application; the risk that the anticipated ownership percentages of the combined company or the amount of the cash dividend to pre-merger Boundless Bio stockholders may change based on adjustments at or prior to closing; risks related to the ability to attract and retain key personnel, including the newly appointed executive officers; the fact that the investigator-initiated trial is being conducted by third parties outside of Serapha’s control, is early stage, involves a limited number of patients, is not designed to support regulatory approval and may not be predictive of the results of Serapha’s planned clinical trials; the uncertainties inherent in clinical development and the regulatory approval process, including the risk that the FDA’s clearance of the IND and its grant of orphan drug and RMAT designations do not ensure or accelerate approval; the combined company’s ability to successfully develop and, if approved, commercialize SERP-01; the combined company’s reliance on third parties in connection with manufacturing, research and clinical and preclinical testing; Serapha’s reliance on intellectual property rights licensed from YolTech Therapeutics and other risks related to the protection of intellectual property; the combined company’s need for substantial additional funding; and other risks described in Boundless Bio’s filings with the SEC, including its most recent Annual Report on Form 10-K and subsequent Quarterly Reports on Form 10-Q, and in the registration statement on Form S-4 and the proxy statement/prospectus to be filed in connection with the proposed merger. Should one or more of these risks or uncertainties materialize, or should any of the parties’ assumptions prove incorrect, actual results may vary in material respects from those projected in these forward-looking statements. You should not place undue reliance on these forward-looking statements. Forward-looking statements speak only as of the date of this release, and neither Serapha nor Boundless Bio undertakes any obligation to update them except as required by law.

No Offer or Solicitation
This press release is not intended to and shall not constitute (i) a solicitation of a proxy, consent or approval with respect to any securities or in respect of the proposed merger or (ii) an offer to sell or the solicitation of an offer to buy or subscribe for any securities, nor shall there be any sale, issuance or transfer of securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. No offer of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the Securities Act of 1933, as amended, or an exemption therefrom.

Important Additional Information and Where to Find It
In connection with the proposed merger, Boundless Bio intends to file with the SEC a registration statement on Form S-4 that will include a proxy statement of Boundless Bio and a prospectus of Boundless Bio (the “S-4”), and each of Boundless Bio and Serapha may file with the SEC or furnish to the SEC other relevant documents concerning the proposed merger. Boundless Bio has confidentially submitted a draft of the S-4 to the SEC for nonpublic review. The draft registration statement is not publicly available, and the S-4 will be publicly filed with the SEC before any solicitation of proxies from Boundless Bio’s stockholders. INVESTORS AND SECURITYHOLDERS ARE URGED TO READ THE S-4, INCLUDING THE PROXY STATEMENT/PROSPECTUS CONTAINED THEREIN, AND ALL OTHER RELEVANT DOCUMENTS FILED WITH OR FURNISHED TO THE SEC IN CONNECTION WITH THE PROPOSED MERGER, AS WELL AS ANY AMENDMENTS OR SUPPLEMENTS TO THESE DOCUMENTS, CAREFULLY AND IN THEIR ENTIRETY WHEN THEY BECOME AVAILABLE, BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT BOUNDLESS BIO, SERAPHA AND THE PROPOSED MERGER. If and when the S-4 is declared effective, the definitive proxy statement/prospectus will be mailed to Boundless Bio’s stockholders as of the record date established for voting on the proposed merger. Investors and securityholders will be able to obtain free copies of the S-4, including the proxy statement/prospectus contained therein, when available, and other relevant documents filed with or furnished to the SEC by Boundless Bio, through the website maintained by the SEC at www.sec.gov and on Boundless Bio’s investor website at investors.boundlessbio.com. Investors and securityholders are urged to read these materials before making any voting or investment decision with respect to the proposed merger.

Participants in the Solicitation
Boundless Bio, Serapha and their respective directors and executive officers may be deemed to be participants in the solicitation of proxies from Boundless Bio’s stockholders in connection with the proposed merger. Information about Boundless Bio’s directors and executive officers, including a description of their interests in the proposed merger and their ownership of Boundless Bio securities, is set forth in Boundless Bio’s filings with the SEC, including its most recent Annual Report on Form 10-K and its definitive proxy statement filed with the SEC on April 28, 2026. Additional information regarding the persons who may, under the rules of the SEC, be deemed participants in the solicitation of proxies in connection with the proposed merger, including a description of their direct or indirect interests, by security holdings or otherwise, will be included in the S-4 and the proxy statement/prospectus contained therein when they become available. These documents are or will be available free of charge at the SEC’s website at www.sec.gov.

Investors and Media:
Sarah McCabe
ir@seraphabio.com