DNA got most of the attention in your high school biology class, but now it’s time for RNA to be teacher’s pet.
A new class of “RNA interference” drugs with potential to provide a unique approach to cancer treatment was one of the many significant topics of discussion this week at the American Association for Cancer Research annual meeting in Washington D.C.
Data was presented from a first clinical trial on humans that validated the safety and efficacy of a drug that now can block the expression of specific proteins involved in cancer cell division.
“Therapies such as the one used in our study have the potential to make a significant and broad impact on how we treat cancer because we have the ability to target any protein involved in the disease,” said Ramesh K. Ramanathan, M.D., of the Translational Genomics Research Institute in Phoenix, Ariz. “This approach has the potential … to improve outcomes for the patient.”
Ramanathan was one of more than 18,000 researchers and presenters from around the world who attended the five-day conference that covered all aspects of cancer research and wrapped up on Wednesday.
Stopping Aggressive Cancers
RNA interference works by disrupting the production of harmful proteins that contribute to the development of diseases. This is a form of targeted therapy, which is currently a burgeoning area of cancer research.
The RNA interference drug in this particular study was TKM-PLK1. It is being developed by Tekmira Pharmaceuticals Corporation. According to Ramanathan, in an AACR press release this week, TKM-PLK1 targets the specific gene PLK1. Research has proven that PLK1 plays an integral role in many of the more aggressive forms of cancer.
Mesothelioma, which is caused by exposure to asbestos fibers, is among the most aggressive cancers that have been studied by researchers. In the ongoing Phase I human clinical trial of TKM-PLK1, mesothelioma patients were among the participants, which also included patients with cancers of the breast, colon, ovary and lung. Researchers reported that TKM-PLK1 was generally well tolerated by the participants.
Mesothelioma is diagnosed in an estimated 3,000 people each year in the United States. Until a cure is found, innovative studies that explore novel therapies will continue to play a pivotal role for mesothelioma research.
“Our preclinical results have shown that by decreasing PLK1 levels in cancer cells, we can stop tumor growth and kill the cancer cells,” Ramanathan said in the press release.
Ramanathan has been enrolling patients with advanced solid tumors into the ongoing dose-escalation Phase I study. Two of the patients have been involved for more than six months and have shown no evidence of cumulative toxicity. One patient has stable disease and the other a confirmed partial response to the treatment.
Researchers involved with mesothelioma have been predicting that future breakthroughs in treatment likely would come through genetics and gene therapy, along with a more targeted, personalized approach.
Targeting Therapy Drugs
The theme of the this week’s AACR meeting was “Personalized Cancer Care Through Discovery Science.” It celebrated discoveries in translational, basic and clinical cancer research. There was considerable discussion involving the availability of new technologies and the utilization to benefit patients.
There was a similar presentation this week that involved using the engineered antibody MPDL3280A to target the protein PD-L1, which is found on the surface of many cancer cells.
During a recent Phase I clinical trial, it was shown effective across a range of cancers, including kidney, lung, stomach and colon. It also showed few toxic side effects for patients. PD-L1 can impair the ability of a body’s immune system to fight cancer. By effectively disabling it, MPDL3280A can impede the development of cancer.
“It was active with anti-tumor activity across a broad range of cancers,” said Michael S. Gordon, M.D., research director at Pinnacle Oncology Hematology in Scottsdale, Ariz., in a news release. “All of [these immune checkpoint targeting] agents seem to have an exciting activity in patients with metastatic solid tumors.”
The AACR meeting included myriad presentations detailing the latest advancements in cancer research. It also used the meeting to launch its newest journal, Cancer Immunology Research, which will be used to publish cutting-edge research to keep the public informed.
The AACR membership also used the conference in Washington D.C. to lobby the federal government for increased funding for medical research, which has been a tough sell in the current climate of deficit cutting.