The Science Behind the Story:
Targeted-Therapy Cancer Treatment and Research
Fighting cancer at the molecular level could redefine the future of cancer care.
Improving the Standard of Care
More than likely, you or someone you know has been affected by cancer. Perhaps you’re a survivor, caretaker or friend of a cancer victim. Regardless of your association with the disease, you know all too well how devastating a cancer diagnosis can be. But there’s good news: We’re closer than ever before to eradicating this deadly disease.
For decades, chemotherapy has been the treatment of choice for almost every cancer patient, but it has a limited effect when used alone. With chemotherapy, most tumors continue to grow and spread as resistance to the treatment increases. BATTLE (Biomarker-Integrated Approaches of Targeted Therapy for Lung Cancer Elimination), a set of ground-breaking trials taking place at The University of Texas M. D. Anderson Cancer Center, has the potential to affect every type of malignancy, and is proving that targeted therapy may one day change the standard of care for cancer treatment.
Managed by Dr. Roy S. Herbst, professor in the Department of Thoracic/Head and Neck Medical Oncology, the BATTLE project aims to establish molecular-based targeted therapy by first examining the genetic profiles of individual tumors, and then assigning therapies that offer the best benefits based on the tumor’s unique characteristics.
Each tumor is composed of distinctive biomarkers (proteins), and certain cancer drugs are known to attack specific biomarkers. Once physicians determine the genetic makeup of a patient’s tumor, they can match the patient to the drug known to work on his or her unique biomarkers. This approach promises to be more effective than typical treatments, cause fewer side effects and ultimately, eliminate the threat of this devastating disease.
Unlocking the Cure: The Process Behind BATTLE’s Clinical Trials
All patients in BATTLE have late-stage lung cancer that has persisted, grown or returned. Some have been through two or three different treatment regimens. BATTLE’s first step is a fine-needle biopsy of the patient’s tumor. This is unique in that patients usually don’t have additional biopsies beyond initial diagnosis. However, other treatments may have changed the characteristics of the patient’s tumor, so it’s important to capture the current make-up of the tumor before beginning the BATTLE trials.
Drugs being evaluated in BATTLE are Tarceva®, Zactima®, Nexavar® and a combination drug called Targretin®. Patients early in the trial were assigned to one of 20 slots — four drugs against four groups of potential biomarkers and a group with no biomarkers. Patients were placed in the 20 groups based on earlier research to determine which of the biomarkers each drug was likely to target. The four no-biomarker groups will help the researchers identify new biomarkers after the trial closes.
After the first 97 patients enrolled, a second unique feature of BATTLE began. In a process called adaptive randomization, subsequent patients are assigned to a drug based on information gained from the early patients. The statistical design is a well-established way of testing biomarkers in cancer. This aspect of the trial continues, with each patient adding more information for assigning those to come. If one drug fails to help anyone, that particular arm of the study can be closed to new patients. The percentage of patients assigned to one treatment arm might increase while others decrease. If the first drug is not working, a patient can choose to drop out of that trial, have a new biopsy and enter one of the others.
So far, none of the four options has been closed and 237 patients have enrolled over two years. The researchers know which drugs patients receive but are blinded as to the biomarker profiles that led to their assignments to those drugs. When the trial is unblinded, the research team can analyze how the original biomarkers worked and identify new ones that emerged during the trial. The team collects patients’ initial biopsies to compare them to their BATTLE biopsies to learn how lung cancer changes as treatment proceeds. Study participants get a CT scan every eight weeks to evaluate their tumors. After BATTLE ends, a follow-up trial using the same design will test drugs in combination with standard chemotherapy as first-line treatment.