Jan. 17 (UPI) -- Doctors at the University of Colorado Anschutz Medical Campus in Aurora, Colo., have been successful in treating a 26-year-old brain cancer patient who had become resistant to chemotherapy and other treatments with the malaria drug chloroquine.
The patient, Lisa Rosendahl, was diagnosed at the age of 21 with an aggressive form of glioblastoma and her cancer had become resistant to chemotherapy and targeted treatments. Doctors had given her just a few months to live.
Rosendahl was treated with a new drug combination that included the anti-malaria drug chloroquine. By adding this to her treatment, the chloroquine stopped an essential process her cancer cells had been using to resist therapy, re-sensitizing her cancer to the targeted treatment that had stopped working.
"Lisa is a young adult with a very strong will to live," Dr. Jean Mulcahy-Levy, investigator at the University of Colorado Cancer Center, pediatric oncologist at Children's Hospital Colorado and first author of the study, said in a press release. "But it was a high-risk, aggressive glioblastoma and by the time we started this work, she had already tried everything. For that population, survival rates are dismal. Miraculously, she had a response to this combination. Four weeks later, she could stand and had improved use of her arms, legs and hands."
The drug trial was used on two other brain cancer patients and produced similar results, according to researchers.
This new drug combination was created in the laboratory of Andrew Thorburn, Ph.D., deputy director of the CU Cancer Center.
Thorburn and his team of researchers studied the cellular process of autophagy, a process of cellular recycling in which cell organelles or autophagosomes surround dangerous material and transport it to the cell's lysosomes for disposal.
Autophagy breaks down cellular components into building blocks of energy or proteins for use during low-energy periods or to protect it from pathogens. Cancer cells use autophagy to protect themselves against treatment.
Researchers discovered that cancers with mutations in the gene BRAF and those with a mutation called BRAFV600E, including melanomas and epithelioid glioblastomas were very dependent on autophagy.
Rosendahl was initially treated with vemurafenib, a drug used to treat BRAF-positive melanoma, after surgeries, radiation and chemotherapy had not worked. The vemurafenib seemed to treat the cancer at first, but then her cancer developed resistance.
Doctors used chloroquine to stop the BRAFV600E mutation from being dependent on autophagy, which allowed the vemurafenib to start working again.
"We have treated three patients with the combination and all three have had a clinical benefit," Mulcahy-Levy said. "It's really exciting - sometimes you don't see that kind of response with an experimental treatment. In addition to Lisa, another patient was on the combination two-and-a-half years. She's in college, excelling and growing into a wonderful young adult, which wouldn't have happened if we hadn't put her on this combination."
The study was published in eLife.