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    CPMCRI cancer investigators present research at the 2016 American Society of Clinical Oncology annual meeting

    June 3, 2016

    What are the leading advances in cancer research internationally? ASCO 2016 included presentations on this topic by CPMC cancer investigators. Highlights included the following:

    Checkpoint inhibitors—a new class of immunotherapy drugs used in cancer—continue to show beneficial effects in treating melanoma, according to data being presented at the American Society of Clinical Oncology (ASCO) annual meeting in Chicago this week. The immunotherapy drugs are expected to bring new hope to the more than 76,000 people in the U.S. diagnosed annually with this deadly form of skin cancer. Checkpoint inhibitor immunotherapy has also been approved for the treatment of lung, kidney, and bladder cancer, and is being investigated in dozens of other cancers.

    Research by California Pacific Medical Center Research Institute (CPMCRI) Senior Scientist David Minor, MD, and colleagues at leading national cancer centers will be presented at the ASCO meeting, where over one hundred studies of cancer immunotherapy studies are anticipated to be highlighted. Previous findings by Dr. Minor and colleague Mohammed Kashani-Sabet, MD, Director of CPMC’s Cancer Program, were key to FDA approval of nivolumab, an immunotherapy PD-1 inhibitor.

    After a median follow-up of two years, the CheckMate-069 study showed that combined immunotherapy with ipilimumab and nivolumab resulted in higher overall survival (OS) rates compared with nivolumab alone (69% versus 53%) in the overall study population. The regimens were studied in patients with BRAF-positive, advanced melanoma.

    “These results further support the use of combination immunotherapy in treating patients with advanced melanoma. This study is a testament to the complementary mechanisms of action between ipilimumab and nivolumab,” said Dr. Minor, who was a co-author of the CheckMate-069 study. “We are committed to offering patients at CPMC these groundbreaking therapies which are changing the course of cancer treatment.”

    Findings from the CheckMate-069 study build on results from the phase III CheckMate-067 study, which showed improvements in progression-free survival (PFS, i.e., the percentage of patients whose cancer is under control) and objective response rates (ORR, i.e., the percentage of patients who show unequivocal shrinkage of their tumor upon X-ray).

    In the CheckMate-069 phase II study, 142 treatment-naive patients with unresectable stage III or metastatic stage IV melanoma were randomized to ipilimumab plus nivolumab (n = 95) or placebo (n = 47) once every three weeks for four doses. This was followed by nivolumab or placebo every two weeks until disease progression or unacceptable toxicity.

    With 11 months of follow-up, the ORR in the BRAF wild-type group (the primary endpoint) was 61% in the combination arm compared with 11% in the ipilimumab monotherapy arm. The results were similar among all randomized patients, which included patients with BRAF-mutant melanoma.

    The two-year PFS rate with combination treatment in BRAF wild-type tumors was 54% compared with 11% with ipilimumab alone. Similar PFS rates were observed in the all-randomized population. The combination of ipilimumab and nivolumab resulted in a median PFS that still has not been reached at the two-year follow-up. With ipilimumab monotherapy, the median PFS was three months. This reflected a statistically significant 64% reduction (p<0.0001) in the hazard of progression or death in the all-randomized patient population.

    Treatment-related adverse events were consistent with previous reports: most (>85%) resolved with immune-modulating medications, and no additional treatment-related deaths were reported.

    “We eagerly await more information on survival outcomes of this combination therapy which will be derived from the larger, randomized CheckMate 067 trial,” said Dr. Minor.

    In other news at ASCO, John Chan, MD, CPMC scientist and gynecologic oncologist, Sutter West Bay Gynecologic Oncology Lead, presented his research on a new 'dose-dense' strategy for treating ovarian cancer. Learn more about the findings here.