A drug used to lower blood pressure and prevent heart attacks could also be used to treat melanoma. From Penn State, researchers are studying how a specific type of beta blocker - widely available and approved by the FDA - can improve the effectiveness of cancer immunotherapy for melanoma patients whose cancer has spread to different tissues in the body.
Beta blockers reduce blood pressure by opening up blood vessels to improve blood flow and prevent heart attacks by inhibiting the effects of epinephrine, a hormone also called adrenaline. Pan beta blockers are commonly known to be safe, which means that they could be more quickly applied to melanoma patients than a newly developed drug. In theory, beta blockers are able to lower stress to empower the immune system to fight cancer on its own.
"Most patients are either prescribed beta-1 selective blockers or are not taking beta blockers at all,” explained Dr. Todd Schell. “This means there's a large population of patients who may be eligible to take pan beta blockers while being treated with immunotherapy.”
Metastatic melanoma patients receiving immunotherapy may have the best chance at living longer, although even with the treatment the response rates are low - less than 35 percent. “How can we make these treatments better?” asked Penn State’s Dr. Joseph Drabick.
"Beta blockers slow your heart rhythm, but they can also affect immune cells and improve immune function," Schell said. "We wanted to see if there would be a correlation between the beta blockers patients were taking for another condition and their response to immunotherapy.”
The new Penn State study involved giving beta blockers to melanoma patients receiving cancer immunotherapy as opposed to just immunotherapy. Of 195 metastatic melanoma patients being treated with immunotherapy, 62 were also taking beta blockers. Schell, Drabick, and the other researchers compared survival between patients taking two different kinds of beta blockers, beta 1-selective and pan beta blockers, and patients taking no beta blockers at all.
The results showed that patients taking pan beta blockers were significantly more likely to survive (70 percent alive after five years of immunotherapy) than patients taking beta 1-selective beta blockers or no beta blockers at all (25 percent). Researchers completed virtually the same study again, this time in mice with melanoma. Like the human trial, the mice were receiving immunotherapy with or without additional treatment of pan beta blockers. Immunotherapy plus pan beta blockers delayed tumor growth and increased survival.
“We saw that for patients taking pan beta blockers, there was a dramatic improvement in survival, and we were able to duplicate these findings in mice and see the exact same phenomenon,” Drabick explained.
Going forward, the Penn State researchers will continue their study on using beta blockers to improve immunotherapy to potentially treat a variety of cancers.
The present study was published in the journal OncoImmunology.