Mistletoe Extract for Advanced Cancer Treatment? A Johns Hopkins Study Investigates

Mistletoe has been used for centuries to treat conditions including epilepsy, headaches, hypertension, and arthritis. More recent studies have found that mistletoe extract may be helpful for cancer patients, as well. The National Cancer Institute says it’s also commonly prescribed to cancer patients in Europe. A new study aimed to understand how best to administer it.

Researchers at Johns Hopkins Kimmel Cancer Center recently wrapped a phase I trial of intravenous mistletoe extract, known as Helixor M. The trial involved 21 patients with advanced cancer and was designed to evaluate the safety of the treatment and determine dosage for larger clinical trials. The findings, published in the journal Cancer Research Communications, also showed benefits for the patients.

Dr. Channing Paller, lead researcher and 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.”

The patients involved in the study had an assortment of cancers that were advanced and treatment-resistant. They were given three weekly treatments of mistletoe extract until the disease progressed or there was toxicity. The dosage was also gradually increased to determine the upper limit for safety. The maximum tolerated dose was found to be 600 milligrams.

Over a follow-up period of just over 15 weeks, the team also observed stable disease in five patients that lasted for an average of 15 weeks, while three participants saw their tumors shrink and then remained stable for two to five months. The team says that does not meet the criteria for a partial response, however. There were other benefits observed, though, including a reported improvement in quality of life.

The side effects reported included fatigue, nausea, and chills, though participants said they were manageable.

Next up, Paller says, are phase II studies combining mistletoe extract and chemotherapy. They’re waiting on funding for that. The team notes that it’s also important to research how the extract works.

According to the National Cancer Institute, there have been a few large-scale studies of mistletoe extract with breast cancer patients. One found that, when coupled with standard post-surgery treatment for early-stage breast cancer, the extract was linked with less adverse drug reactions. In the second, meanwhile, survival outcomes for patients who had been given mistletoe extract in addition to standard treatment were better than those who had just had standard treatment.