According to researchers, a common, inexpensive drug that is used to prevent heart attacks and lower blood pressure may also help melanoma patients live longer. This study has been published in the journal OncoImmunology.
Researchers at Penn State found that melanoma patients who received immunotherapy while taking a specific type of beta blocker lived longer than patients who received immunotherapy alone. In a follow-up experiment with mice, the researchers saw the same results. "The type of beta blocker we found to be effective against melanoma pan beta blockers was actually the least prescribed," Schell said.
"Most patients are either prescribed beta 1 selective blockers or are not taking beta blockers at all.” Patients with metastatic melanoma, or melanoma that has spread to other parts of the body, often have a poor prognosis, and while some forms of immunotherapy — treatments that boost the body's immune system to fight disease are promising, response rates are less than 35 percent.
Previous research has shown that physiological stress prevents the immune system from fighting tumors effectively, while lower stress boosts the benefits of anti-cancer treatments. The researchers were curious about whether lowering stress with beta blockers would improve outcomes in patients treated with immunotherapies.
"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. For metastatic melanoma, there are currently three different types of immunotherapy approved for use, and we specifically looked at that population of people."
While there was little difference in how long patients taking beta 1-selective blockers or no beta blockers lived, the results indicate that patients taking pan beta blockers lived significantly longer than the others. Five years after immunotherapy, about 70 percent of patients receiving pan beta blockers were still alive, versus about 25 percent of those taking beta 1-selective blockers or no beta blockers at all.
To help explain the results, the team performed a parallel experiment in mice with melanoma. They treated the mice with immunotherapy and with or without the pan beta blocker propranolol. The researchers found that the propranolol significantly delayed tumor growth and increased survival when combined with immunotherapy.
Dr. Joseph Drabick suggest that reducing physiological stress with beta blockers can help improve the effectiveness of immunotherapy and survival for melanoma patients. "The benefit of this is that beta blockers already have a long history of safety in people, and they're cheap and generic,"
Drabick said. "And now they have the potential to augment some of these newer immunotherapy drugs to help people with cancer." In future, they'll be working on a clinical trial to further discover and understand the role of beta blockers in treating cancer.