Blood Pressure Drug Enhances Cancer Treatment

Telmisartan can significantly improve the cancer-killing activity of the targeted therapy olaparib, potentially expanding its use to more patients.

Mar. 26, 2026 at 3:49am

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In a new Dartmouth Cancer Center study, investigators found that the FDA-approved blood pressure drug telmisartan can significantly enhance the cancer-killing activity of the targeted therapy olaparib. The combination was found to boost production of type I interferons, which help the immune system recognize and attack cancer, and reduce levels of PD-L1 inside tumor cells, further increasing its therapeutic potential.

Why it matters

PARP inhibitors like olaparib are particularly effective in tumors with certain DNA repair defects, but many tumors lack these defects, limiting the number of patients who can benefit. Additionally, most cancers eventually develop resistance to PARP inhibitors. This study shows that telmisartan, a common and safe blood pressure drug, can make tumors more vulnerable to PARP inhibitors, even when they lack the specific DNA repair defects that usually make PARP inhibitors effective.

The details

Telmisartan was found to increase DNA damage in tumor cells when used with olaparib and trigger powerful immune-stimulating signals. Specifically, the combination boosted production of type I interferons, which help the immune system recognize and attack cancer. Telmisartan also reduced levels of PD-L1 inside tumor cells, a protein that cancers use to evade immune attack, further increasing its therapeutic potential.

  • The findings are newly published in The Journal for ImmunoTherapy of Cancer.

The players

Tyler J. Curiel

The study's senior and lead author, a clinical researcher at the Dartmouth Cancer Center.

Dartmouth Cancer Center

The institution where the study was conducted.

Telmisartan

An FDA-approved blood pressure drug that was found to enhance the cancer-killing activity of the targeted therapy olaparib.

Olaparib

A targeted therapy that works by exploiting weaknesses in how some cancer cells repair damaged DNA.

PARP inhibitors

A class of cancer therapies that include olaparib, which are particularly effective in tumors with certain DNA repair defects.

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What they’re saying

“This study shows that a common, safe, tolerable, convenient, and inexpensive drug may significantly improve how well an important class of cancer therapies works.”

— Tyler J. Curiel, Senior and lead author of the study

“Telmisartan has several distinct anticancer effects that, together with targeted therapy, could make tumors more responsive to distinct types of treatments. We showed the improved efficacy with PARP inhibitors in this study, but we also have good data showing that telmisartan improves efficacy of distinct chemotherapy classes and immunotherapies in many other cancer types through related mechanisms.”

— Tyler J. Curiel, Senior and lead author of the study

What’s next

Curiel and colleagues at the Dartmouth Cancer Center are already testing the telmisartan and olaparib combination in patients through two ongoing clinical trials, one in men with metastatic, castration-resistant prostate cancer and the other in platinum-resistant ovarian cancer.

The takeaway

This study highlights the potential for a common, safe, and inexpensive blood pressure drug to significantly enhance the effectiveness of an important class of cancer therapies, potentially expanding treatment options for many more patients and overcoming resistance to these drugs.