What are RAS inhibitors and why are they important in pancreatic cancer?
For decades, mutations in the KRAS gene have been one of the greatest challenges in pancreatic cancer research. Present in approximately 90% of pancreatic ductal adenocarcinomas, this gene drives tumour growth and has traditionally been extremely difficult to target therapeutically.
The arrival of RAS inhibitors has marked a turning point. For the first time, we have drugs capable of directly targeting one of the most common molecular alterations in this tumour.
Recently, together with Paula Lynch and Grainne M. O'Kane, we published an article in the News & Views section of Nature Medicine analysing an international study focused on the mechanisms that may limit the effectiveness of RAS inhibitors and their implications for the future of these treatments.
Why do some tumours stop responding to RAS inhibitors?
Despite the promising results achieved so far, these treatments have also revealed new challenges. As with many targeted therapies, some tumours develop mechanisms that limit their effectiveness.
The study we discuss identifies several molecular mechanisms that may explain why some tumours stop responding to RAS inhibitors. The findings show that some tumours develop molecular alterations capable of reactivating signalling pathways associated with tumour growth, which may reduce the effectiveness of these treatments.
These findings contribute to a better understanding of the mechanisms that limit the efficacy of RAS inhibitors and provide valuable information to guide future therapeutic strategies.
RAS inhibitor resistance: understanding it to develop new treatments
One of the study’s main contributions is that it provides valuable information for designing more effective therapeutic approaches. Identifying how tumours escape treatment allows researchers to begin exploring ways to block or even anticipate these mechanisms.
In our News & Views article published in Nature Medicine, we highlight that resistance to RAS inhibitors is likely a complex and heterogeneous phenomenon. A better understanding of this diversity of mechanisms will be essential to optimise the use of these treatments and continue advancing their clinical development.
This knowledge helps guide future research efforts and the development of new therapeutic strategies.
Combination therapies: the future of pancreatic cancer treatment
One of the key ideas emerging from both the study and our analysis is that the future is unlikely to rely on a single drug. Understanding resistance mechanisms may help design more rational combination therapies tailored to the alterations that arise during treatment.
Identifying which alterations emerge as tumours evolve may allow the selection of strategies aimed at simultaneously blocking different pathways involved in tumour growth.
The goal is to move towards more personalised approaches adapted to the molecular characteristics of each tumour. In this context, understanding the mechanisms that limit treatment response becomes an essential tool for improving patient outcomes.
New challenges in pancreatic cancer treatment
RAS inhibitors have opened a new chapter in the treatment of pancreatic cancer, a disease that still presents significant unmet medical needs.
The major challenge now is to better understand the mechanisms that limit response to these inhibitors and determine how this knowledge can be translated into new therapeutic strategies for patients with pancreatic cancer.
The study’s findings reinforce the importance of identifying and characterising these mechanisms in order to optimise the use of RAS inhibitors and guide future therapeutic strategies.
These strategies are currently being evaluated in clinical trials aimed at improving outcomes for patients with pancreatic cancer, including studies involving the Medical Oncology Department of Hospital Clínic Barcelona.
References:
Lynch P, Macarulla T, O'Kane GM. From RAS inhibitor resistance to rational combination strategies. Nature Medicine. 2026. DOI: 10.1038/s41591-026-04529-w.
Aronchik I et al. Acquired resistance to the RAS(ON) multi-selective inhibitor daraxonrasib guides rational combination therapy strategies in pancreatic cancer. Nature Medicine. 2026. DOI: 10.1038/s41591-026-04537-w.
