HYB-BKV, a solution for reducing kidney transplant damage and rejection risks

HYB-BKV is a new RNA-based drug for the treatment of BK virus (BKV) reactivation in kidney and bone marrow transplant patients. It can block BKV reactivation and prevent impaired functioning of the transplanted kidney and extend graft lifespan, while reducing the risk of organ rejection and renal failure.


HYB-BKV is being developed by Hybridize Pharma, a pharmaceutical spin-off from the Leiden University Medical Center (LUMC).

Hybridize Pharma’s mission

Our mission is to develop innovative RNA-based therapeutics specifically targeting viruses that become reactivated under immunosuppression.

The need

Annually, almost 90,000 kidney patients worldwide receive a kidney transplant. To minimize the risk of (acute) rejection of the donor kidney by the recipient’s immune system, immunosuppressive therapy is essential. Importantly, it is estimated that >95% of the human population is a carrier of BKV (in their kidneys), but the virus is not known to cause harm in healthy individuals, as a fully operational immune system ensures that BKV remains in ‘sleep’ mode. However, repression of the immune system frequently leads to reactivation of latent BKV in the transplanted kidney.


In approximately 35-40% of kidney transplant patients, high-levels of BKV are detected in blood (known as BK viremia), oftentimes requiring doctors to reduce the levels of immunosuppression in efforts to reduce BKV levels. This can take weeks to months and detrimentally impact kidney function and graft lifespan. In an estimated 10% of cases this can lead to severe kidney damage and thereby increase the risk of kidney loss.


Hybridize Pharma, together with our team of dedicated scientists at the Department of Nephrology at the Leiden University Medical Center (LUMC) has developed an innovative treatment to meet this unmet clinical need. Our compound provides hope to these patients that BKV will no longer be able to compromise the function and lifespan of their new kidney and lease-on-life.

The product

Our RNA-based therapy with nuclease-resistant antisense oligonucleotides (ASO) prevents reactivation of BKV. The ASO treatment prevents BKV genome replication, virus production and reinfection (of neighbouring cells).


This patented technology reduces local and distal BKV spread and will preserve kidney function after transplantation. The ASOs are small and have a long lifespan, can be administered intravenously and localize to the kidney.

Who we are

We are a pre-clinical stage biotech company that spun-out from the Leiden University Medical Center in 2019. We are an R&D performing SME, creating value by developing RNA-based therapeutics that specifically target viruses that become reactivated under immunosuppression. We have the ambition to become a global player in developing anti-viral therapies.


The concept between Hybridize Pharma was founded in July 2018 by Eric van der Veer, Anton Jan van Zonneveld and Jurriën Prins.

Watch here the interview with the Nierstichting about HYB-BKV

Latest publication

"Niet meer kiezen tussen twee kwaden"

Source: Leidsch Dagblad

Read more