Orthogon Therapeutics Raises Additional $11M in Funding for its BK Virus Antiviral Drug Program

CANTON, Mass. – Orthogon Therapeutics today announced the closing of an $11 million follow-on financing, bringing its total funding to $36 million. This funding supports the continued progress of its first-in-class drug against BK polyomavirus. BK virus infection is a major cause of complications in transplant patients, without approved treatment.

“We developed this program to meet the realities of transplant care,” said Ali H. Munawar, Ph.D., CEO of Orthogon Therapeutics. “We've designed around those constraints, arriving at a personal profile that we're happy to develop.”

The company is a pioneer in oral therapy that addresses the spectrum of BK infections, from early reactivation through systemic spread and the onset of severe disease. By targeting viral proteins previously considered inaccessible to small molecule drugs, Orthogon develops a solution where other therapies have failed.

Orthogon's lead product specifically targets the viral capsid protein (VP1), delivering a powerful anti-viral effect at the site of viral replication. Intracellular activity leads to the continuous control of viral infection in all types of BK and related human polyomaviruses, especially in transplant patients, where the persistence of the virus causes infections.

“This is not a common antivirus setting. We built this program to meet the realities of transplant care,” said Ali H. Munawar, Ph.D., CEO of Orthogon Therapeutics.These patients are treated within a small balance of immunosuppression, organ function, and a large burden of pills. We designed around those limitations, arriving at a candidate profile that we were happy to develop.“

Similarly, Orthogon published findings examining hundreds of patient-derived BK virus sequences, showing that the virus carries pre-existing diversity in antibody-binding sites and that it replicates beyond the reach of circulating antibodies. These studies explain the limited clinical benefit seen with inactive antibodies, challenges that the Orthogon drug is designed to overcome.

The program uses Orthogon's novel portfolio of small molecules that target each of two viral proteins: the VP1 capsid and the large T antigen (LTAg), an ability that has eluded it for decades. This program will be included in the leading transplant and virology meetings in 2026, building on the findings presented at ASN in 2025.

Along with its primary focus on polyomaviruses, Orthogon is developing programs in additional areas of unmet need in transplant-related diseases.

https://www.businesswire.com/news/home/20260417911548/en/

Ali H. Munawar, Ph.D.
[email protected]
1-339-502-8643

Maria Martin
[email protected]
1-339-502-8630