A pilot trial to assess whether assigning treatment based on specific gene mutations can provide benefit to patients with metastatic solid tumors is being launched this month by the National Cancer Institute (NCI), part of the National Institutes of Health.
The Molecular Profiling based Assignment of Cancer Therapeutics, or M-PACT, trial is one of the first to use a randomized trial design to assess if assigning treatment based on genetic screening can improve the rate and duration of response in patients with advanced solid tumors. A trial in which patients are randomly assigned to various treatment options is the gold-standard method for determining which treatment option is best.
Researchers hope that in addition to the knowledge gained from the trial about assigning therapy based on results of genetic sequencing of tumors, this trial could identify patient sub-groups that are likely to benefit from certain treatments and result in new treatments being developed quickly for some cancers. This could ultimately lead to smaller, more definitive clinical trials, which would be helpful to clinicians and patients in terms of cost and time.
“Patients will have their tumors genetically screened and if a pre-defined mutation is found, they will receive treatment with targeted agents,” said Shivaani Kummar, M.D., head of NCI’s Developmental Therapeutics Clinic and the principal investigator of the trial. “What we don’t know, however, is whether using this approach to assign targeted treatments is really effective at providing clinical benefit to patients, as most tumors have multiple mutations and it’s not always clear which mutation to target and which agent is most likely to provide maximal benefit. This study hopes to address some of these questions in the context of a prospective, randomized trial.”
Very few types of tumors have just one mutated gene that triggers cancer progression. Once a gene is mutated, it can lead to the activation of multiple pathways, resulting in disease progression and potentially requiring multiple interventions. Therefore, NCI’s M-PACT trial is designed to determine whether people with specific mutations that have been demonstrated in laboratory systems to affect drug effectiveness will benefit from a specifically chosen targeted intervention and if these interventions lead to better outcomes.
For NCI’s M-PACT study, after screening hundreds of people, 180 patients with advanced refractory solid tumors (those resistant to standard therapy) will be enrolled based on their genetic profile. During the screening process, samples of the tumors will be genetically sequenced to look for a total of 391 different mutations in 20 genes that are known to affect the utility of targeted therapies. If mutations of interest are detected, using a molecular sequencing protocol for tumor biopsy samples evaluated by the U.S. Food and Drug Administration, those patients will be enrolled in the trial and randomly assigned to one of two treatment arms to receive one of the four treatment regimens that are part of this study.
To ensure that patients receive the best treatment already known to provide benefit, patients with specific tumor types should have received certain therapies prior to being enrolled in NCI’s M-PACT. For instance:
• Patients with melanoma whose tumors have mutations in the V600E region of the BRAF gene should have received and progressed on a specific BRAF inhibitor therapy to be eligible for NCI’s M-PACT trial.
• Patients with lung cancer should have had their tumors tested for the presence of EGFR and ALK gene mutations, and, if mutations were detected, they should have received and progressed on therapies targeting EGFR or ALK, respectively.
Patients with all types of solid tumors will be considered for trial eligibility. For the randomization, patients will be assigned to Arm A (they will receive a treatment regimen prospectively identified to target their specific mutation or relevant pathway) or Arm B (they will receive a treatment regimen not prospectively identified to target their specific mutation or relevant pathway).
Patients in Arm B will have the option to cross over to Arm A to receive therapy identified to target their specific mutation or relevant pathway if their disease progresses on their initial study treatment. As of January 2014, the study is open for patient accrual. Clinicians hope that they can rapidly enroll patients and report results of their findings by 2017.
“We believe that this study will aid patients in the trial that will be conducted initially at the NCI, and subsequently expanded to clinical trials sites participating in the NCI-supported Early Therapeutics Clinical Trials Network,” said James Doroshow, M.D., NCI deputy director for clinical and translational research. “We also believe that M-PACT can be a model for trials nationwide, particularly those that employ genetically-driven treatment selection approaches in their design.”