By Amy LeBlanc
Precision oncology is a term that has been thrown around a lot in recent years. But what does it actually mean? For Maarten Ligtenberg, CEO and Co-founder of Flindr Therapeutics, it’s all about understanding the fundamentals of cancer biology — what drives the survival of tumor cells and how these mechanisms can be disrupted with targeted therapies.
“This is our vision for the future of cancer treatments,” says Ligtenberg. “We’re working on creating new medicines and identifying potential biomarkers that can be used to develop precise, effective solutions, and screening patients to see who is most likely to benefit from our drugs.”
Flindr’s name derives from the Dutch word ‘vlinder’, meaning butterfly. For the startup, the metamorphosis from caterpillar to butterfly serves as an apt metaphor for its approach to drug development, where fundamental target biology insights evolve into targeted cancer treatment.
The process relies on their collaboration with one of its founding institutions, the Netherlands Cancer Institute (NKI), where observations from the clinic are translated into laboratory models. These models are then used in genome-wide genetic screens to uncover the biological drivers that are essential for tumor survival, and therefore promising drug targets. The mode of action of the drug targets are then explored further together with the company’s other founding institution, the VIB-UGent Center for Inflammation Research (VIB).
“We start from what we see in patients and use that to guide everything we do. That’s how we find targets that are directly relevant for cancer treatment,” explains Ligtenberg.
Flindr’s lead compound is a small molecule drug, inhibiting an enzyme called RNF31, which acts as a central regulator of whether a cancer cell lives or dies. RNF31 functions as part of a system that protects cells from death signals. In many cancers, this protection is overactive, allowing tumor cells to survive and continue growing when they should be eliminated.
“Cancer cells hijack this mechanism by switching it ‘ON’ to stay alive,” explains Ligtenberg. “RNF31 is essentially a master switch. We’re developing a drug that flips the switch back ‘OFF’, re-enabling cell death so that the body can go back to clearing out the cancer cells on its own.”
This approach is particularly relevant in cancers such as B-cell lymphomas and ovarian cancer, where RNF31 plays a key role in tumor survival. The company is exploring RNF31 and other biomarkers it can use to identify patients most likely to respond and is seeking validation of this in the clinic.
Flindr’s RNF31 inhibitor has already demonstrated promising results as a standalone treatment in preclinical studies. Given its central role in cancer cell survival, the drug may also have potential in combination with existing therapies, particularly in settings where tumors become resistant to treatment, with the aim of enhancing treatment effectiveness and improving patient outcomes.
“Combination approaches are becoming increasingly important in oncology,” says Ligtenberg. “By targeting a mechanism that helps cancer cells survive treatment, our approach would strengthen the impact of existing therapies and ultimately help more patients benefit.”
Following a €20 million Series A in 2024, Flindr will launch a Series B fundraising round by the end of 2026 to finance the company’s transition into clinical activities. Flindr is also working on expanding its pipeline, which already includes a second program — another first-in-class drug target, identified via the same discovery process as RNF31. When asked about the future, Ligtenberg is very optimistic:
“I’m really looking forward to bringing RNF31 to the clinic, because it’s unlocking a key mechanism of action that should have a huge impact on the lives of cancer patients,” he says. “I believe that focusing on the right biology is what ultimately makes the difference. If you understand the mechanism, you can develop therapies that truly have an impact for patients.”
