Viennese Pioneer of
a New Class of Drug

Impact Story


The drug thalidomide, which was approved in 1957 and caused severe fetal deformities, went down in history as a medical catastrophe. Researchers have now discovered that the mechanism behind this fatal effect holds the key to a whole class of new therapeutic drugs. Georg Winter from CeMM – Research Center for Molecular Medicine in Vienna is researching these agents, known as glue degraders, which can specifically switch off disease-causing proteins. The spin-off company Proxygen is continuing with the approach and applying it to drug development – well-known pharmaceutical companies are already on board.

Over the course of a lifetime, many genetic mutations accumulate in the body’s cells – changes that can have fatal consequences. The mutated genes can lead to the production of new proteins that disrupt the delicate balance of the cell: They can falsely activate or suppress signals, promote cell division, or prevent cells from dying. In the worst-case scenario, they can cause cancer.

There are cellular protein quality control systems in place to eliminate these defective proteins. So-called E3 ubiquitin ligases, for example, are part of a cellular recycling system. They recognize proteins with structural irregularities and mark them for targeted destruction. However, cancer-causing proteins based on mutated genes are usually not recognized. This is precisely where a promising new approach in medical research comes in.  “Molecular earmarking” helps identify proteins that have gotten out of control as faulty so they can be eliminated.

One researcher who has been influential in basic research in this field for years is Georg Winter. He worked at Harvard University in the USA, among other places, before making significant progress as a group head at CeMM – Research Center for Molecular Medicine, where he worked with a particularly efficient form of these artificial markers known as glue degraders. “Molecular glue” ensures that a pathogenic protein is specifically brought together with a suitable E3 ligase and marked for elimination. The potential for future therapies for cancer and many other serious diseases is enormous.

In a nutshell

Georg Winter is researching novel strategies to target disease-causing proteins. His work focuses on glue degraders – small molecules that act like a molecular glue and mark pathological proteins for destruction by cellular degradation. These discoveries will allow researchers to develop  new therapeutic approaches against cancer and other serious diseases. Proxygen, a start-up co-founded by Winter that identifies candidates for the development of new therapeutics, is one of the pioneers in this young field of drug development. Heavily financed collaborations with international pharmaceutical companies demonstrate the potential of the approach and support Vienna as a life science location.

Portrait of Georg Winter
From academic research to the founding of a spin-off to a position in science management: Georg Winter, Life Sciences Director at the AITHYRA Institute of the Austrian Academy of Sciences © ÖAW/Daniel Hinterramskogler
Black-and-white graphic of a chameleon with the inscription “THE ART OF Glue HUNTING”
Using knowledge from basic research to develop new medical therapies: Proxygen, a spin-off of the CeMM – Research Center for Molecular Medicine of the Austrian Academy of Sciences, is based on preliminary research work in FWF projects by molecular biologist Georg Winter. © www.proxygen.com

“Collaborations like this are beneficial because they show that Austrian companies can grow out of the local biotope and play a global role”

Development cooperation worth billions

The highly successful research led to the founding of the Viennese start-up Proxygen in 2020, which Winter launched together with Matthias Brand, Stefan Kubicek, and Giulio Superti-Furga. Here, the researchers are dedicated to the systematic search for these glue degraders. Their approach has already led to promising results, which Proxygen is continuing to develop together with renowned partners. In addition to collaborations with German pharmaceutical manufacturers Boehringer Ingelheim and Merck, the 2023 announcement of a €2.3 billion collaboration with the US pharmaceutical group MSD caused a stir.

“Collaborations like this are beneficial because they show that Austrian companies can grow out of the local biotope and play a global role,” says Georg Winter in an interview with scilog, the FWF’s science magazine. The CeMM researcher and Proxygen co-founder has since taken on another key role in Austrian medical science. In April 2025, he took over as Scientific Director for Life Sciences at AITHYRA, the Research Institute for Biomedical Artificial Intelligence of the Austrian Academy of Sciences (ÖAW).

Successful research at Harvard

The foundations for Winter’s career can be found in his early research. He completed his doctorate at the Medical University of Vienna, researching cellular responses and resistance to cancer drugs at CeMM. During his postdoctoral phase at the Dana-Farber Cancer Institute at Harvard Medical School, he started focusing on the research field of degraders. Here, however, the emphasis was on a different type than in his later work – so-called PROTACs. They can simultaneously dock onto a target protein and an effector and bring them into close proximity, because they have a customized binding structure for each of the two interaction partners.

A study by Winter and colleagues from 2015 is considered a milestone in the practical applicability of these drugs. In the journal Science, they were able to show for the first time that PROTACs are effective in living organisms. “In a proof-of-concept study, they demonstrated selective degradation of a transcriptional coactivator called bromodomain-containing protein 4 and delayed the progression of leukemia in mice,” Science summarized at the time. These research results led to the founding of the US start-up C4 Therapeutics, which is now listed on the stock exchange and also focuses on the targeted degradation of disease-causing proteins.

Short bio

Georg Winter is Adjunct Principal Investigator at CeMM – Research Center for Molecular Medicine in Vienna and head of the Chemical Biology of Oncogenic Gene Regulation research group. He worked at CeMM during his doctoral studies before joining the Dana-Farber Cancer Institute at Harvard Medical School in the USA, where he was involved in pioneering work on the targeted degradation of proteins. In 2016, he set up his research group at CeMM with the help of several project grants from the Austrian Science Fund (FWF). The group focuses on glue degraders, special drugs for protein degradation. He co-founded the spin-off Proxygen, which systematically searches for these agents, in 2020. In 2025, Winter also took on the role of Scientific Director for Life Sciences at AITHYRA, the Research Institute for Biomedical Artificial Intelligence of the Austrian Academy of Sciences (ÖAW).

Georg Winter standing between rounded shelves with a brochure in his hand
“Every new Viennese or Austrian success story makes the location more attractive for highly skilled people,” says Georg Winter. © Christian Hofer

Efficient solution, but hard to find

In 2016, Winter returned to CeMM in Vienna as as a project head, where he and a newly established working group started focusing on a field that had never been given as much attention as PROTACs – glue degraders. They have one key advantage: Unlike PROTACs, they do not need to have binding sites for both elements, as they only act on the E3 ligase to specifically change the binding capacity there. The catch to this very efficient solution, which uses small molecules with significantly better oral bioavailability than the often large-molecule PROTACs, is that glue degraders are extremely difficult to find.

So far, they have mainly been discovered by chance – sometimes only in the aftermath of a medical catastrophe. A drug called thalidomide, introduced in Germany in 1957 as the over-the-counter sleeping pill Contergan, led to severe fetal deformities when taken during pregnancy. Researchers only discovered what caused the drug to have these fateful consequences a few years ago. It turned out that thalidomide functions as a glue degrader. It binds to certain E3 ligases and causes them to break down specific proteins that are important for early embryonic development during pregnancy – resulting in fetal malformations.

The search for active agents

This new insight laid the foundation for the new class of drugs. The aim was to identify molecules that specifically – and exclusively – target selected disease-causing proteins. Winter and his team at CeMM have considerably expanded existing knowledge of the different types of glue degraders and how to characterize them. “For example, in 2019, we published our findings on the genetic switch that can be used to switch 300 of the approximately 600 E3 ligases on or off at once,” explains Winter in the scilog interview. “This was followed in 2020 by a publication describing how this mechanism can be used to search for molecular glues.”

These results and the accompanying patents provided the foundation for the development of Proxygen’s method for a targeted search for new glue degraders. In addition to an ERC grant, this high-impact basic research was made possible between 2016 and the founding of the company in 2020 with three project grants from the Austrian Science Fund (FWF). Proxygen’s research platform has the potential to open up completely new approaches for treating a wide range of diseases, possibly allowing the utilizazion of proteins that have until now proven to be unsuitable for conventional drugs.

Today, the CeMM spin-off is one of the most successful life science start-ups in Austria. Collaborations with well-known institutions and companies help make Vienna more visible on the map of global biotech hotspots. “There are talented young people in Vienna, but many still have little experience in the biotech sector,” summarizes the Proxygen founder in the scilog interview. “With every new success story in Vienna or Austria, the location becomes more attractive for skilled people to take the plunge and put down roots here.”

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