Study Investigates Mistletoe Extract for Treating Cancer

The phase one trial found that mistletoe extract delivered intravenously improved quality of life and reduced tumor size in some study participants.

Mistletoe is a parasitic plant that grows on the branches of trees and derives its nutrients and water from the host tree. This plant is most associated with Christmas traditions, where people often hang it in doorways and other prominent places during the holiday season.

In addition to its traditional significance, some research suggests it may have anticancer properties.

Although mistletoe has shown promise as a potential cancer treatment in clinical studies, many of those investigations had weaknesses that raised doubts about their reliability.

Now, a small study published on February 9 in Cancer Research Communications found that intravenous injections of mistletoe extract (ME) — also known as Helixor M — reduced tumor size and improved quality of life in people with cancer.

In the phase one trial — aimed at identifying a safe ME dose for a phase 2 trial — scientists from the Johns Hopkins Kimmel Cancer Center gave 21 participants with cancer increasingly higher doses of ME through intravenous injection. The participants received the escalated doses three times per week until their cancer progressed or they experienced symptoms of ME toxicity.

According to the study, the maximum tolerated dose of ME was 600mg, and the most frequently reported side effects were fatigue, nausea, and chills. Although participants also reported those effects were manageable.

After an average follow-up of around 15 weeks, the team found that cancer tumors in five participants stabilized, and tumors in three participants shrunk in size. Additionally, the participants reported an overall improved quality of life.

In a Johns Hopkins article, lead researcher Channing Paller, M.D., an associate professor of oncology, says, "intravenous mistletoe demonstrated manageable toxicities with disease control and improved quality of life in this group of patients, who had already received multiple cancer therapies."

Paller also notes that they plan to initiate phase two trials combining ME with chemotherapy, depending on funding.