What's Happening?
Xeris Biopharma Holdings, Inc. hosted a webinar to outline its extensive clinical development strategy for XP-8121, an investigational once-weekly subcutaneous levothyroxine formulation designed for hypothyroidism treatment. The company announced that
its Phase 3 registrational study, named Cornerstone, is on track to begin by the end of 2026, with topline results anticipated in late 2028. Xeris projects potential U.S. FDA approval and commercial launch for XP-8121 in 2030, estimating peak net revenue potential between $1 billion and $3 billion. The Cornerstone study aims to demonstrate therapeutic equivalence of once-weekly subcutaneous XP-8121 to daily oral levothyroxine in 500 adults and adolescents with well-controlled hypothyroidism across over 50 U.S. clinical trial sites. Key opinion leader Dr. David Robertson, an endocrinologist and Cornerstone investigator, highlighted the persistent challenges faced by patients who do not achieve TSH normalization with existing oral therapies, emphasizing XP-8121's potential to offer a differentiated approach. The program also includes Capstone, a pediatric study, and Touchstone, a study for patients with inconsistent thyroid control.
Why It's Important?
XP-8121 represents a significant potential advancement in the treatment of hypothyroidism, a condition affecting approximately 20 million Americans. A substantial portion of these patients, estimated at 3 to 5 million, struggle to achieve adequate biochemical control due to issues like variable gastrointestinal absorption and drug interactions associated with daily oral levothyroxine. Uncontrolled hypothyroidism can lead to serious health consequences, including cardiovascular disease and increased mortality. A once-weekly subcutaneous injection could offer improved patient adherence, more consistent drug delivery, and better biochemical control, potentially redefining the standard of care. For Xeris Biopharma, the successful development and commercialization of XP-8121 could establish it as a leading biopharmaceutical company, given the substantial market potential and the unmet need it addresses. The projected peak net revenue of $1 billion to $3 billion underscores the commercial significance of this product candidate.
What's Next?
Xeris Biopharma is set to initiate its Phase 3 registrational study, Cornerstone, by the end of 2026. This study will enroll 500 patients across more than 50 U.S. clinical trial sites, with results expected in late 2028. Following the Cornerstone study, the company plans to initiate the Touchstone study in 2027, which will evaluate XP-8121 in patients with inconsistent thyroid control. The Capstone pediatric study will also confirm appropriate dosing and evaluate safety in younger patients. If clinical trials are successful, Xeris anticipates filing a New Drug Application (NDA) with the U.S. FDA, with potential approval and commercial launch projected for 2030. The company will also continue to generate real-world evidence to quantify the burden of inadequate thyroid control. Stakeholders, including endocrinologists and patients, will closely watch the progress of these trials for a potential new treatment option.
