“The now-published results from the EMBRACA study confirm that talazoparib (Pfizer), a poly-adenosine diphosphate-ribose polymerase (PARP) inhibitor, prolongs progression-free survival (PFS) in patients with advanced BCRA-positive breast cancer compared with single-agent chemotherapy alone, and that it also significantly improves quality of life.
” ‘This is the largest randomized trial in BRCA mutation carriers [ever undertaken] and demonstrates PARP efficacy,’ Jennifer Litton, MD, associate professor in the Department of Breast Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, told Medscape Medical News in an email.”
“In a randomized, Phase II trial led by researchers at The University of Texas MD Anderson Cancer Center, adding the PARP inhibitor veliparib to a standard chemotherapy agent improved overall response rates (ORR) in patients with small cell lung cancer (SCLC). Researchers also identified a select group of patients—those whose tumors expressed SLFN11— who also saw a progression-free survival (PFS) and overall survival (OS) benefit, suggesting a promising biomarker for the PARP-inhibitor sensitivity in SCLC.
“The study was published in Journal of Clinical Oncology. Ongoing follow-up studies are underway to confirm the results, which could result in the first new therapeutic option for this rare and aggressive lung cancer in more than three decades, said Lauren Averett Byers, M.D., associate professor of Thoracic/Head and Neck Medical Oncology.”
“A new drug application (NDA) for the PARP inhibitor talazoparib has been granted a priority review by the FDA for the treatment of patients with germline BRCA mutation–positive, HER2-negative locally advanced or metastatic breast cancer, according to Pfizer, the manufacturer of the agent.
“In results from the phase III EMBRACA trial, on which the application is based, talazoparib reduced risk of disease progression or death by 46% compared with chemotherapy in patients with BRCA-positive advanced breast cancer. At a median follow-up of 11.2 months, the Median progression-free survival (PFS) at the median follow-up of 11.2 months was 8.6 months (95% CI, 7.2-9.3) with talazoparib versus 5.6 months (95% CI, 4.2-6.7) with physician’s choice of therapy (HR, 0.54; 95% CI, 0.41-0.71; P <.0001). The objective response rate (ORR) was 62.6% (95% CI, 55.8-69.0) compared with 27.2% (95% CI, 19.3-36.3), respectively (odds ratio, 4.99; 95% CI, 2.9-8.8; 2-sided P value <.0001).”
“Half of patients with metastatic triple-negative breast cancer (TNBC) achieved disease control when treated with the combination of a poly (ADP-ribose) polymerase (PARP) inhibitor and an anti–PD-1 agent, a preliminary prospective study showed.
“Overall, 13 of 46 evaluable patients had objective responses to treatment with niraparib (Zejula) and pembrolizumab (Keytruda). An additional 10 patients had stable disease. Clinical activity was observed in patients beyond those with germline BRCA mutations.”
“In a small Phase II study of early-stage breast cancer patients with BRCA1/2 mutations, researchers at The University of Texas MD Anderson Cancer Center found that more than half of the women who took the PARP inhibitor talazoparib once daily prior to surgery had no evidence of disease at the time of surgery. If further validated in larger, confirmatory trials, the oral medication could replace chemotherapy for these patients.
“The trial, which expands upon a feasibility study published in npj Breast Cancer, was presented today as an oral presentation at the 2018 American Society of Clinical Oncology Annual Meeting by Jennifer Litton, M.D., associate professor of Breast Medical Oncology.”
“The U.S. Food and Drug Administration today expanded the approved use of Lynparza (olaparib tablets) to include the treatment of patients with certain types of breast cancer that have spread (metastasized) and whose tumors have a specific inherited (germline) genetic mutation, making it the first drug in its class (PARP inhibitor) approved to treat breast cancer, and it is the first time any drug has been approved to treat certain patients with metastatic breast cancer who have a “BRCA” gene mutation. Patients are selected for treatment with Lynparza based on an FDA-approved genetic test, called the BRACAnalysis CDx.”
“Although modern immunotherapy has yet to have a breakthrough in prostate cancer to the degree it has had in lung cancer or urothelial carcinoma, combinations with anti–PD-1/PD-L1 agents are beginning to show promise for these patients in clinical trials.
“Currently ongoing is a phase II trial of durvalumab (Imfinzi) in combination with the PARP inhibitor olaparib (Lynparza) in patients with metastatic castration-resistant prostate cancer (mCRPC; NCT02484404). Investigators note that previous data have suggested that 25% to 30% of sporadic mCRPC has DNA-repair pathway defects. Results thus far have demonstrated that the synergy of durvalumab and olaparib proves that the combination may be a viable option for patients with mCRPC who are heavily pretreated. The trial is still accruing.”
“The PARP inhibitor talazoparib significantly increased progression-free survival (PFS) over physician’s choice of therapy in a randomized phase III trial of patients with advanced breast cancer and a germline BRCA mutation.
“ ‘Talazoparib is a highly potent, dual-mechanism PARP inhibitor. It prevents the repair of DNA damage, and results in cell death,’ said Jennifer K. Litton, MD, of the University of Texas MD Anderson Cancer Center in Houston. A previous phase II study showed encouraging efficacy with the agent in patients with BRCA1/2 mutations, which led to the new EMBRACA trial. Litton presented results of the trial at the 2017 San Antonio Breast Cancer Symposium (SABCS), held December 5–9.”
Last month, the annual American Society of Clinical Oncology (ASCO) meeting took place in Chicago. Thousands of oncologists, patients, and journalists gathered to learn about the most recent developments in cancer research and treatment. Here are some breast cancer highlights from the meeting:
Triple negative breast cancer (TNBC) is considered more responsive to treatment with immune checkpoint drugs than any other type of breast cancer. So far, these drugs have primarily been explored in metastatic TNBC, in combination with chemotherapy. The combination of “anti-PD-L1” and “anti-PD-1” immune checkpoint drugs with chemotherapy has now been examined in early-stage TNBC, in which a breast tumor can be surgically removed after neoadjuvant chemotherapy. Continue reading…