āshibio Expands Clinical Pipeline with Vantictumab, a First-In-Class Antibody for Autosomal Dominant Osteopetrosis Type 2

- Company’s second clinical-stage asset licensed from Mereo Biopharma based on novel insights generated in a mouse model of osteopetrosis -

- āshibio has exclusive license to develop and commercialize vantictumab globally, excluding Europe, where Mereo retains commercial rights -

- Vantictumab development program is supported by safety and biomarker data generated in previous clinical trials -

BURLINGAME, Calif.--(BUSINESS WIRE)-- āshibio, a privately held, clinical-stage biotechnology company developing novel therapeutics for the treatment of bone and connective tissue disorders, today announced an exclusive licensing agreement with Mereo BioPharma (NASDAQ: MREO) for vantictumab for the treatment of autosomal dominant osteopetrosis type 2 (ADO2), a rare, debilitating bone disorder with no approved therapies. The licensing of vantictumab represents a strategic expansion of āshibio’s pipeline of clinical-stage assets that address high unmet needs and carry significant clinical and commercial potential.

ADO2, also known as Albers-Schönberg disease, is a genetic disorder caused by reduced function of osteoclasts. Impaired osteoclast function results in dense, brittle bone and leads to complications such as multiple fractures, poor bone healing, low blood counts (due to bone marrow sequestration), and painful nerve compression. The most common form of osteopetrosis, ADO2 results from a mutation in the chloride channel 7 (CLCN7) gene and has a reported incidence of 1 in 20,000 births.¹

“People living with autosomal dominant osteopetrosis type 2 face a lifetime of bone-related complications resulting in significant morbidity, multiple surgical procedures, chronic pain, and impaired quality of life – yet patients have no approved therapy to address the disease,” said āshibio Chief Executive Officer Pankaj Bhargava, MD. “Bringing vantictumab into our pipeline reflects our commitment to advancing therapies for rare skeletal conditions and improving the lives of those affected by serious bone disorders.”

Vantictumab is a monoclonal antibody that selectively binds to certain frizzled (Fzd) receptors and inhibits Wnt signaling pathways.² Originally intended for the treatment of cancer, vantictumab has been previously evaluated in oncology clinical trials, demonstrating a favorable safety and pharmacokinetic profile. Previous clinical trials have provided biomarker data that directly support the activity of vantictumab on osteoclast function. These data significantly derisk the clinical program and allow āshibio to rapidly advance vantictumab into clinical development for ADO2.

Preclinical data supporting the development of vantictumab in ADO2 will be presented at the upcoming American Society for Bone and Mineral Research (ASBMR) annual meeting, which takes place September 5-8, 2025 in Seattle, Wash.

Under the terms of the agreement, āshibio will lead global clinical development for vantictumab in adult and pediatric patients. Mereo has granted āshibio an exclusive license to develop and commercialize vantictumab in the US and the rest of the world, excluding Europe, where Mereo retains commercial rights.

About āshibio
āshibio is a privately held, clinical-stage biotechnology company developing a pipeline of novel therapeutics for the treatment of bone disorders. Founded in 2022, āshibio exited stealth mode in June 2024 with $40 million in seed and Series A financing. The company has initiated a Phase 2/3 trial of its lead asset, andecaliximab, in patients with fibrodysplasia ossificans progressiva (FOP), a rare genetic disorder characterized by progressive heterotopic ossification (HO), a pathological condition characterized by abnormal bone formation in muscle and soft tissues. āshibio has also initiated a development program in non-hereditary heterotopic ossification (NHHO), a severely disabling condition for which there are no approved therapies. The first study in the NHHO program is a Phase 1b trial of andecaliximab in patients with spinal cord injury at risk of HO. For more information, visit www.ashibio.com.

About Mereo BioPharma
Mereo BioPharma is a biopharmaceutical company focused on the development of innovative therapeutics for rare diseases. The Company has two rare disease product candidates: setrusumab for the treatment of osteogenesis imperfecta (OI); and alvelestat for the treatment of severe alpha-1 antitrypsin deficiency-associated lung disease (AATD-LD). Mereo’s partner, Ultragenyx Pharmaceutical, Inc., has completed enrollment in the Phase 3 portion of a pivotal Phase 2/3 study in pediatric patients and young adults (5 to 25 years old) for setrusumab in OI and in the Phase 3 study in pediatric patients (2 to <7 years old). The partnership with Ultragenyx includes potential additional milestone payments of up to $245 million and royalties to Mereo on commercial sales in Ultragenyx territories. Mereo has retained EU and UK commercial rights and will pay Ultragenyx royalties on commercial sales in those territories. Setrusumab has received Orphan Designation for osteogenesis imperfecta from the European Commission (“EC”) and the U.S. Food and Drug Administration (FDA), PRIME designation from the European Medicines Agency (EMA), and Breakthrough Therapy and Rare Pediatric Disease Designations from the FDA. Alvelestat has received Orphan Designation for AATD from the EC and the FDA, and Fast Track designation from the FDA for AATD-LD. Mereo has also entered into an exclusive global license agreement with ReproNovo SA, a reproductive medicine company, for the development and commercialization of leflutrozole, a non-steroidal aromatase inhibitor.

In addition to the rare disease programs, Mereo has two oncology product candidates, etigilimab, an anti-TIGIT; and navicixizumab for the potential treatment of late-line ovarian cancer. Navicixizumab has been partnered with Feng Biosciences, Inc. in a global licensing agreement that includes milestone payments and royalties. For more information, visit www.mereobiopharma.com.

¹ Wu CC, Econs MJ, DiMeglio LA, et al. Diagnosis and management of osteopetrosis: consensus guidelines from the Osteopetrosis Working Group. J Clin Endocrinol Metab. 2017 Sep 1;102(9):3111-3123. doi: 10.1210/jc.2017-01127
² Diamond JR, Becerra C, Richards D, et al. Phase Ib clinical trial of the anti-frizzled antibody vantictumab (OMP-18R5) plus paclitaxel in patients with locally advanced or metastatic HER2-negative breast cancer. Breast Cancer Res Treat. 2020 Aug 14;184(1):53–62. doi: 10.1007/s10549-020-05817-w

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Source: āshibio