Preclinical data support a differentiated profile combining rapid sFlt1 reduction and fast systemic clearance of the ATAC to enable titratable dosing, with no placental transfer

Avilar Therapeutics, a biopharmaceutical company pioneering extracellular protein degradation, today announced that preclinical data from its sFlt1 ATAC (ASGPR Targeting Chimera) program for the treatment of preeclampsia will be featured in a poster on display at the 2nd Hamburg International Symposium on Maternal-Fetal Medicine, being held October 9-10, 2026, in Hamburg, Germany. The data mark the program’s first disclosure at a scientific meeting focused on maternal-fetal medicine.

According to the World Health Organization, preeclampsia affects up to 8% of pregnancies worldwide and remains without an approved therapy that directly addresses the underlying disease biology. Delivery of the baby, often preterm, remains the only definitive treatment. Elevated circulating sFlt1, produced in excess by the placenta, is a central driver of the disease, contributing to the blood vessel dysfunction and organ damage that characterize the condition. Reduction of circulating sFlt1 is being evaluated as a treatment strategy for safely delaying delivery in patients with preeclampsia.

Avilar has developed an sFlt1 ATAC that binds sFlt1 in the maternal circulation and directs it to the liver for degradation via the body's natural asialoglycoprotein receptor (ASGPR) pathway, actively removing the protein. The sFlt1 ATAC uses a bispecific antibody that selectively binds the circulating sFlt1 isoforms i13 and e15a and incorporates its proprietary ASGPR-targeting technology to enable hepatocyte uptake and endolysosomal degradation. This unique mechanism of action is designed to rapidly reduce levels of circulating sFlt1 and enable urgent treatment of patients with preeclampsia in the acute care setting.

Key findings from the data featured in the poster include:

• Rapid sFlt1 lowering: Avilar’s sFlt1 ATAC demonstrated substantial lowering of circulating sFlt1 in non-human primates within hours, showing rapid pharmacologic activity in a disease where time to effect is clinically important.
• Fast systemic clearance: In vivo studies showed the sFlt1 ATAC was rapidly cleared from circulation, supporting a “fast-on, fast-off” profile and the potential for individualized, titratable dosing.
• No placental transfer: No transfer of the sFlt1 ATAC across the placenta was observed in studies conducted in pregnant non-human primates, supporting the potential to minimize fetal drug exposure.

“What differentiates the sFlt1 ATAC profile is the combination of rapid and substantial lowering of circulating sFlt1 with fast clearance of the ATAC that may support individualized dosing as a patient’s condition evolves. Importantly, in our preclinical studies the molecule did not cross the placenta,” said Phil Graham, Ph.D., Chief Development Officer at Avilar.

“Preeclampsia represents exactly the kind of unmet medical need where we believe our ATAC platform is particularly well suited – a disease in which a circulating protein plays a central pathogenic role and where rapid, controllable reduction of that protein may be particularly valuable," said Leslie Meltzer, Ph.D., Chief Executive Officer of Avilar. "With a development candidate in hand and work underway to advance it toward clinical trials, we are focused on translating these attributes into meaningful benefit for preeclampsia patients and their babies.”

The poster, entitled "An sFlt1-Targeted Degrader for Early-Onset Preeclampsia,” will be available on the company’s website following the conference.

About Avilar Therapeutics

Avilar Therapeutics is a biopharmaceutical company pioneering the discovery and development of extracellular protein degraders. Avilar develops ATACs (ASGPR Targeting Chimeras) that harness the liver's natural asialoglycoprotein receptor (ASGPR)-mediated degradation pathway to selectively remove pathogenic extracellular proteins from circulation.

Avilar is advancing a pipeline of ATAC programs across multiple therapeutic areas with significant unmet need. Its lead program targets circulating sFlt1, a key driver of preeclampsia. Additional programs include an IgM-targeting ATAC for IgM-mediated diseases, with an initial focus on anti-MAG neuropathy, an oral ApoB-targeting ATAC for cardiovascular disease, and an oral IgG-targeting ATAC for autoimmune diseases. Across the pipeline, Avilar employs biologics, peptides and small molecules as target-binding modalities. These capabilities extend the platform to a broad range of extracellular pathogenic protein targets.

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Rapid sFlt1 lowering, fast systemic clearance, and no placental transfer.