AiCuris and Hybridize Therapeutics enter worldwide license agreement of up to €100M for a direct-acting RNA-based therapy against BK Virus

February 9, 2022

AiCuris and Hybridize Therapeutics enter worldwide license agreement of up to €100M for a direct-acting RNA-based therapy against BK Virus






  • AiCuris acquires exclusive rights to develop and commercialize Hybridize’s program to prevent severe disease from BK virus (BKV) infections in immunocompromised patients
  • Both companies to collaborate in further development until start of clinical studies expected to start within two years
  • BKV reactivation poses a significant unmet medical need in patients undergoing kidney transplantation
  • BKV-associated nephropathy is one of the leading causes of allograft loss in kidney transplant recipients
  • BKV is difficult to treat, RNA antisense oligonucleotides are a promising novel approach to block BKV replication
  • With the licensed program, AiCuris is building on its strong track record in the field of transplant infections



Wuppertal, Germany and Leiden, The Netherlands, February 9, 2022 – AiCuris Anti-infective Cures AG (AiCuris), a leading company in the discovery and development of drugs against infectious diseases, and Hybridize Therapeutics (Hybridize), focused on the development of RNA-based therapies for patients with acute and chronic kidney diseases, today announced that they have entered into a worldwide licensing agreement for Hybridize’s BK virus (BKV) program. The licensed program is based on a novel RNA-based therapeutic approach developed by Hybridize.


Under the terms of the agreement, AiCuris will gain exclusive rights to develop and commercialize Hybridize’s BKV program, with focus on the treatment of BK virus-mediated nephropathy in renal transplant patients. Hybridize will receive an upfront payment and further milestone payments of up to €100 million in total based on successful achievement of development, regulatory and commercialization goals. In addition, Hybridize will receive tiered royalties on net sales. Hybridize and AiCuris will collaborate in the further development of the BKV-targeting therapy until the start of clinical studies, which is expected within two years.


“We are excited to gain the rights to this exciting RNA-based antisense approach against BKV infections, further strengthening our anti-infective pipeline and building on our strong track record in the field of infectious diseases in transplant patients,” said Dr. Holger Zimmermann, CEO of AiCuris. “With PREVYMIS® approved and licensed to MSD for use in bone marrow transplants for the prevention of cytomegalovirus (CMV) infections, and Pritelivir in phase 3 development for the treatment of acyclovir-resistant mucocutaneous HSV infections in immunocompromised patients, this BKV-targeting RNA-based therapeutic approach represents our third project in the field of transplantation medicine.”


“BKV infection is one of the most common viral infections affecting kidney transplant patients. Yet, there are no treatments approved to fight them,” he continued. “BK virus is difficult to treat as it is not addressable using conventional approaches such as classical enzyme inhibitors. We believe that antisense oligonucleotides are a promising novel approach to block BKV replication. If shown to be safe and effective, this approach could be a true game changer in transplantation medicine with the potential to prevent kidney transplant patients from developing graft rejection and organ loss due to BKV.”


Hybridize’s RNA-based program is designed to target a protein critical for viral replication by modulating the splicing process of the protein-encoding mRNA, preventing its synthesis and thus replication of the virus. The Hybridize program is believed to be the only direct acting antiviral therapeutic in development, working intracellularly and therefore protecting the kidney cells from within. In several scientific papers, antisense oligonucleotides were shown to be effective inhibitors of hepatitis B virus replication in vitro.


“Today’s announcement represents a major milestone and a great validation for our cutting-edge RNA platform technology, and testament to the creative intelligence at the LUMC and great execution of our team to progress this program to this stage,” said Eline van Beest, CEO of Hybridize Therapeutics. “We are convinced that AiCuris’ excellence in the development of anti-infective therapies and its deep and proven experience in bringing drug candidates through clinical development and onto the market makes them the perfect partner to advance our RNA-based BKV program to the clinic. We are very much looking forward to working with the AiCuris team to accelerate the delivery of this promising program to patients who suffer from BKV-associated nephropathy. Also, the upfront and milestone payments will considerably increase our fire power and allow us to expand our proprietary pipeline with a number of as yet undisclosed RNA therapies.”



BK viral infection destroys 10% of all transplanted kidneys

Prevalent in 60-90% of people globally, the polyoma BK virus (BKV) is a latent renal virus that can cause severe complications e.g., in immunocompromised patients undergoing kidney transplantation. As a consequence of modern potent immunosuppressive drugs, aimed at reducing acute rejection and improving transplant survival, BKV-positive individuals are at risk of developing BKV-associated nephropathy and losing their kidney graft. Other common complications include immediate and severely painful bleeding bladder infections (hemorrhagic cystitis), and/or renal dysfunction, leading to prolonged hospitalization. There are currently no approved antiviral drugs to treat BKV infections. For these immunocompromised patients, the current treatment is to reduce the amount of immunosuppression therapy. However, this increases the likelihood of acute or chronic transplant rejection and loss.



About Antisense Oligonucleotide (ASO) technology

In recent years, nucleic acid-based therapeutics have demonstrated efficacy in the treatment and prevention of various diseases, including as part of vaccine development. ASO technology uses complementary single-stranded short oligonucleotide sequences to bind to a target RNA and trigger degradation or block the binding of cellular factors or complexes to the target RNA, thereby correcting defective RNA production in various genetic disease settings. ASO-based therapies have been used for several indications, including the treatment of genetic disorders, cancer, and viral infections.



About AiCuris Anti-infective Cures AG

AiCuris was founded in 2006 as a spin-off from Bayer and focuses on the discovery and development of drugs targeting infectious diseases. SANTO Holding is the Company’s majority investor. PREVYMIS® (Letermovir), a first-in-class non-nucleoside cytomegalovirus (CMV) inhibitor acting via a novel mechanism of action, was licensed to MSD in 2012 and is approved in the EU, the USA, Japan and other parts of the world for use in bone marrow transplants for the prevention of HCMV infections in adults who receive an allogeneic hematopoietic stem cell transplant. The Company is developing drugs for the treatment of viruses such as human CMV, herpes simplex virus (HSV), hepatitis B virus (HBV), and adenoviruses as well as for SARS-CoV‑2 and other viruses with pandemic potential. In the field of antibacterials, AiCuris seeks to develop innovative treatment options for indications with high medical need, including life-threatening, multidrug-resistant, hospital-treated pathogens.

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About Hybridize Therapeutics

Hybridize Therapeutics is a spin-off from the Department of Nephrology at the Leiden University Medical Center (LUMC). The LUMC has played pioneering role in both nephrology (kidney dialysis) and RNA-based medicine (oligonucleotide chemistry and synthesis). Hybridize has merged these areas in its mission, focusing on helping patients overcome untreated kidney diseases with high unmet medical needs using RNA-based therapeutics. Next to its program on BK-virus, Hybridize has a pipeline of programs ongoing leveraging a similar RNA-based strategy as applied for the BKV programs. The program areas include undisclosed molecules targeting kidney monogenic diseases and anti-inflammation/fibrosis.

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AiCuris Anti-infective Cures AG

Katja Woestenhemke

Phone: +49 202 317 63 0


Media Relations

MC Services AG

Dr. Solveigh Mähler

Phone: +49 211 529 252 19



Hybridize Therapeutics

 Eline van Beest

Phone: +31 642241411