A drug that doctors use for high blood pressure might also help a key cancer medicine work better, according to scientists at Dartmouth Cancer Center. The blood‑pressure pill telmisartan made the cancer drug olaparib kill more tumor cells in lab tests.
Why PARP Inhibitors Need a Boost
Olaparib belongs to a group called PARP inhibitors. These medicines target cancer cells that cannot fix broken DNA properly. They work best in tumors with BRCA gene changes. Many cancers lack these DNA flaws, so the drugs often fail or stop working after a while.
Researchers discovered that telmisartan can make even those resistant tumors more vulnerable to PARP inhibitors.
Helping the Immune System Fight Cancer
When telmisartan and olaparib were combined in pre‑clinical studies, the cancer cells showed more DNA damage. At the same time, the mix sparked the immune system, raising levels of type I interferons—proteins that alert immune cells to attack the tumor.
Scientists think this immune boost is a big reason the combination works well.
Telmisartan Stands Out Among Blood‑Pressure Drugs
Telmisartan is part of the angiotensin‑II receptor blocker (ARB) family. When the team tested other ARBs, none showed the same cancer‑fighting effect. Telmisartan also lowered the amount of PD‑L1 protein on tumor cells, a marker many cancers use to hide from the immune system.
Fast‑Track Clinical Trials
Because telmisartan is taken by mouth, has a long safety record, and works in people without high blood pressure, it can be tested quickly in cancer patients. Dartmouth has started two trials.
The first trial mixes telmisartan with olaparib in men whose prostate cancer has spread and stopped responding to hormone therapy. One participant showed an impressive response. The second trial added the combo for women with ovarian cancer that no longer reacts to platinum drugs.
Researchers hope the new approach will help more patients benefit from PARP inhibitors and may also improve the results of other chemotherapy and immunotherapy treatments.