Striking new paths for personalized Medicine

Error-Free Genome Editing

PROVIREX Genome Editing Therapies GmbH is a privately-held biotech company developing first-in-class advanced therapy medicinal products (ATMPs). PROVIREX’s technology is based on error-free genome editing for eradication of life-threatening persistent virus infection.

PROVIREX employs site-specific recombinase-based genome surgery technology to precisely excise chromosomally integrated viral genomes (proviruses). The major advantage of site-specific recombinases is that they function independently of host DNA repair. Therefore, in contrast to other gene editing technologies, they act with nucleotide precision producing completely error-free recombinants.

The engineered recombinase Brec1 excises HIV-1 proviruses with high specificity from the genome of infected host cells. Brec1 activity has unparalleled and lasting antiviral effects in vitro and in vivo. Consequently, plasma viral load declines to levels below the detection limits of the most sensitive assay systems. No viral rebound has been observed.

The following video schematically depicts the therapeutic mechanism of Brec1.


On the road

April 2020

Ascenion GmbH and Innovationsstarter Fonds Hamburg GmbH have acquired shares in PROVIREX

Researchers from Hamburg are planning to use a new gene and cell method to improve the treatment of HIV patients in the future. Under the umbrella of the Hamburg biotech start-up “PROVIREX”, they are developing a new therapeutic approach that uses so-called gene scissors to cut out the blueprint of the AIDS pathogen HIV from the genome of the infected cell and eliminate the virus. This approach could for the first time succeed in removing the virus instead of keeping it in check, as is common with previous forms of treatment. Ascenion GmbH and Innovationsstarter Fonds Hamburg GmbH have acquired shares in the newly founded company PROVIREX. The Start-up will drive the further development of the Brec1 technology, especially with regard to simplified and direct forms of application. Original press release


March 2020

PROVIREX Genome Editing Therapies GmbH and Pantherna Therapeutics GmbH are developing lipid-based delivery systems for mRNA-directed genome editing of lymphocytes for the treatment of HIV and other life-threatening persistent viral diseases.

PROVIREX and Pantherna Therapeutics have entered into a research collaboration. Based on Pantherna’s proprietary PTXxLNP delivery technology both parties will develop and evaluate novel lipid-based mRNA formulations for the transfection of CD4+ lymphocytes. PTXxLNP is a promising candidate for the non-viral delivery of PROVIREX’s proprietary antiviral genome editing tool Brec1.


November 2019

PROVIREX’s  proprietary Brec1 technology is currently entering clinical testing as a first-in-human phase Ib/IIa clinical trial (HIVcure) aiming to remove HIV-1 from infected subjects using gene editing of the patient’s peripheral blood (hematopoietic) stem cells. HIVcure is being carried out at the University Medical Center Hamburg-Eppendorf (UKE) in collaboration with the Leibniz Institute for Virology (LIV, former HPI). Original press release


November 2019

Company foundation of PROVIREX Genome Editing Therapies GmbH

Further Reading



Popular science article from magazine Brand Eins about Provirex and the HIVCURE study (in german only)

Further reading


Karpinski et al. (2016). Directed evolution of a recombinase that excises the provirus of most HIV-1 primary isolates with high specificity. Nat Biotechnol. 34:401-409.

Buchholz & Hauber (2016). Antiviral therapy of persistent viral infection using genome editing. Curr Opin Virol. 20:85-91.

Meinke et al. (2016). Cre Recombinase and Other Tyrosine Recombinases. Chem Rev. 116:12785-12820.

Hauber et al. (2013). Highly significant antiviral activity of HIV-1 LTR-specific Tre-recombinase in humanized mice. PLoS Pathog. 9:e1003587.

Buchholz & Hauber (2013). Engineered DNA modifying enzymes: components of a future strategy to cure HIV/AIDS. Antiviral Res. 97:211-217.

Buchholz & Hauber (2011). In vitro evolution and analysis of HIV-1 LTR-specific recombinases. Methods. 53:102-109.

Sarkar et al. (2007). HIV-1 proviral DNA excision using an evolved recombinase. Science. 316:1912-1915.


Who we are

PROVIREX is a spin-off of the Leibniz Institute for Virology (LIV, former HPI) and is based in Hamburg, Germany. Our team combines profound expertise in biotechnology (particularly genome editing), virology, cell biology, drug development and commercialization.

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PROVIREX Genome Editing Therapies GmbH

c/o Start-up Labs Bahrenfeld

Luruper Hauptstraße 1

22547 Hamburg, Germany

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