Polyomaviruses (BKV & JCV)

September 27, 2021

Polyomaviruses (BKV & JCV)

BK virus & JC virus are part of the polyomavirus family. Both reside in a permissive form in the urinary tract in 60-90% of the general population. In an immunocompromised patient, they can reactivate and kill the organ in which they replicate. No (effective) treatment exists for both viruses.


BK virus
BK virus can wreak havoc in kidney transplant patients, where it slowly destroys the transplanted kidney allograft leading to (premature) allograft loss. In addition, in hematopoietic stem cell transplant patients, BK virus causes an extremely painful, bleeding bladder infection leading up to months prolonged hospitalization.


JC virus
JC virus can become activated in severely immunocompromised patients and can relocate to the central nervous system. Here it leads to the brain disease: progressive multifocal leukoencephalopathy. Symptoms include cognitive / behavioral abnormalities, sensory & motor deficits, speech impairments, seizures and rapid death.


At Hybridize Therapeutics, we are developing antisense oligonucleotides that target the Achilles’ heel of polyomaviruses. This is the only therapeutic in development that is a direct acting anti-viral which works intra-cellular and protects the cells from within. It is designed to target the viral mRNA and therefore provides for low off-target effects.