The “Undruggable” Cancer Target Is No Longer Untouchable

For decades, RAS has been one of the biggest challenges in cancer drug development.

The family of RAS proteins plays a central role in controlling cell growth and survival, and mutations in RAS are found across a wide range of cancers. Yet despite decades of research, scientists struggled to develop medicines that could effectively target these proteins.

That may now be changing.

In September 2026, Revolution Medicines received regulatory approval for Rasonque (daraxonrasib), an oral RAS-targeted therapy for metastatic pancreatic cancer. The approval marks an important milestone in a field that has spent years trying to turn one of oncology’s most difficult biological targets into a clinically useful drug.

Why RAS has been so difficult to target

RAS proteins act like molecular switches inside cells. When functioning normally, they help regulate processes such as cell growth and division. Mutations can leave these switches permanently activated, sending signals that encourage cancer cells to grow and survive.

The problem for drug developers was that RAS proteins have historically been difficult to bind effectively with conventional drug molecules.

For years, the scientific challenge was therefore not simply finding a drug that could interact with RAS, but finding one that could do so in a way that meaningfully disrupted the cancer-driving signal without causing unacceptable effects elsewhere.

The breakthrough has come from a better understanding of the molecular structure and behaviour of specific RAS mutations.

From impossible target to therapeutic opportunity

Rasonque is designed to target KRAS G12D, one of the most important cancer-driving mutations within the RAS family. The drug works by binding to the altered protein and interfering with its ability to continue transmitting growth signals.

That matters particularly in pancreatic cancer, where KRAS mutations are extremely common and treatment options for advanced disease remain limited.

The significance of the development goes beyond a single drug, however.

The approval demonstrates that targeting RAS-driven biology can produce a clinically meaningful therapeutic approach. It also validates years of research into highly selective RAS inhibitors and creates a foundation for developing additional drugs against other RAS mutations.

The beginning of a larger RAS race

Rasonque is only part of the story.

Other companies are pursuing their own RAS-targeted therapies, while Revolution Medicines is also developing additional candidates designed to address different RAS mutations and potentially combine RAS inhibition with other cancer treatments.

This raises an important question for oncology: if individual RAS mutations can be targeted successfully, how far can the approach ultimately go?

The answer could involve combinations of targeted therapies, immunotherapies and other treatments designed around the molecular characteristics of an individual tumor.

What this means for drug development

The RAS story is a useful reminder that some of the biggest advances in medicine do not necessarily come from discovering an entirely new biological pathway.

Sometimes the breakthrough comes from finally finding a way to intervene in a pathway scientists have understood for decades.

For pharma R&D, the implications are significant. Advances in structural biology, molecular design, computational tools and biomarker-driven clinical development are making previously difficult targets increasingly accessible.

The term “undruggable” may therefore be becoming less of a scientific category and more of a temporary description.

RAS was once considered one of the clearest examples of a target that could not be effectively addressed with drugs.

Now, the industry is entering a new phase: determining just how many RAS-driven cancers can be treated, how durable those responses can be, and how these therapies can be combined with existing standards of care.

The next challenge is no longer proving that RAS can be targeted.

It is expanding what that breakthrough can achieve.