Drug used for breast, kidney cancers may also extend survival for head and neck cancers

SCOTTSDALE, Az., February 27, 2020 -- A targeted therapy drug used for breast and kidney cancers may also extend progression-free survival for patients with advanced head and neck cancer who are at high risk for recurrence after standard treatment. Patients enrolled in a randomized phase II trial who received the mTOR inhibitor everolimus were more likely to be cancer-free a year after therapy than those who took a placebo drug, and the benefit persisted for those with mutations in their TP53 gene. The findings may present a new treatment option for a group of patients whose survival rates have not improved in more than 30 years.

The study will be presented at the 2020 Multidisciplinary Head and Neck Cancers Symposium, taking place February 27-29 in Scottsdale, Arizona.

"While cure rates tend to be upwards of 85% for patients with head and neck cancers associated with HPV, they tend to be less than 40% for patients with disease related to smoking," said lead author Cherie-Ann O. Nathan, MD, professor and chair of otolaryngology/head and neck surgery at Louisiana State University (LSU) Health Shreveport and director of head and neck surgery at Feist-Weiller Cancer Center. "These patients are recurring most often, and their survival rates have not changed in decades, despite advances in surgery, radiation therapy and chemotherapy."

To address this disparity, the researchers focused on patients with advanced, HPV-negative head and neck squamous cell carcinoma (HNSCC), or HPV-positive disease and smoking history of more than 10 pack-years, and enrolled 52 patients to receive up to one year of either everolimus or a placebo drug. Eligible patients had to be free of disease after either definitive treatment with chemoradiation therapy or surgery followed by chemoradiation. Researchers then tracked how long they remained cancer-free with additional therapy.

After a year, 81% of patients on everolimus remained progression-free, compared to 57% of those in the placebo group (p=0.039). Dr. Nathan clarified that this timepoint was not stipulated a priori and is a post-hoc analysis. Two-year progression-free survival, which was the primary endpoint, continued to favor everolimus but was no longer significant. Subset analysis determined that for patients with TP53 mutations, the survival difference remained significant for an additional year after they stopped immunotherapy (two-year PFS of 70% vs 22.5%, p=0.036). The difference was not significant at two years for patients without the mutation.

While TP53 mutations occur in almost 80% of HPV-negative, smoking related cases of HNSCC, the potential link between TP53, the mTOR pathway and survival was a surprise to the researchers. "There's really no drug that targets TP53, and so we've never had a targeted therapy for it or considered it an actionable mutation," she said.

Sixteen of the 28 patients on everolimus and seven of the 24 patients on the placebo drug experienced Grade 3 or higher toxicities, including three and five serious adverse events, respectively. Dr. Nathan said the drug's tolerability indicates that it may have potential as longer-term maintenance therapy to delay recurrence for high-risk patients.

"Although the sample size is small, as it closed due to lack of accrual, these finding indicate that patients at high risk for tumor relapse could be given mTOR inhibitors to stall progression and keep any residual cancer cells from growing. Our hope is that head and neck cancer can be treated as chronic disease, similar to some breast cancers," she explained. "Everolimus is used for patients with breast cancer or renal cell cancer for extended periods without major side effects, and there is potential for patients with TP53-mutated head and neck disease to see a survival benefit, as well."

Additional trials are needed to confirm the link between TP53 and survival, as well as to determine the safety of keeping patients with HNSCC on the drug for multiple years.

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Dr. Nathan, who is also the current President of the American Head and Neck Society, will present "Multi-Institutional Randomized Double-Blind Phase II Trial of Everolimus vs. Placebo as Adjuvant Therapy in Patients with Locally Advanced Squamous Cell Cancer of the Head and Neck" (Abstract 5) today during the symposium's Plenary Session. The investigator-initiated trial was sponsored by the University of Chicago and funded by Novartis. Email press@astro.org for a copy of the abstract or presentation slides from the meeting.

Attribution to the 2020 Multidisciplinary Head and Neck Cancers Symposium requested in all coverage. This release includes updated information not available in the abstract.

2020 Head and Neck Cancers Symposium News Planning Team

Robert L. Ferris, MD, PhD; Maie St. John, MD, PhD; Francis P. Worden, MD; Charu Aggarwal, MD, MPH; Sue Yom, MD, PhD; Brian O'Sullivan, MD, FASTRO; disclosures available online.

ABOUT THE SYMPOSIUM

The 2020 Multidisciplinary Head and Neck Cancers Symposium is a two-and-a-half-day meeting that convenes radiation oncologists, medical oncologists, surgeons and all members of the treatment team for a practical and comprehensive examination of treatment advances for patients with head and neck cancers. Scientific, interactive and case-based educational sessions will cover the latest research on multidisciplinary therapies, clinical applications and new treatment strategies, supportive care and toxicity mitigation. The meeting is cosponsored by the American Society for Radiation Oncology (ASTRO), the American Society of Clinical Oncology (ASCO), the American Head and Neck Society (AHNS) and the Society for Immunotherapy of Cancer (SITC).

ABOUT ASTRO

The American Society for Radiation Oncology (ASTRO) is the world's largest radiation oncology society, with more than 10,000 members who are physicians, nurses, biologists, physicists, radiation therapists, dosimetrists and other health care professionals who specialize in treating patients with radiation therapies. The Society is dedicated to improving patient care through professional education and training, support for clinical practice and health policy standards, advancement of science and research, and advocacy. ASTRO publishes three medical journals, International Journal of Radiation Oncology * Biology * Physics, Practical Radiation Oncology and Advances in Radiation Oncology; developed and maintains an extensive patient website, RT Answers; and created the nonprofit foundation Radiation Oncology Institute. To learn more about ASTRO, visit our website and follow us on our blog, Facebook, Twitter and LinkedIn.

ABOUT ASCO

Founded in 1964, the American Society of Clinical Oncology (ASCO) is committed to making a world of difference in cancer care. As the world's leading organization of its kind, ASCO represents more than 40,000 oncology professionals who care for people living with cancer. Through research, education, and promotion of the highest-quality patient care, ASCO works to conquer cancer and create a world where cancer is prevented or cured, and every survivor is healthy. ASCO is supported by its affiliate organization, the Conquer Cancer Foundation. Learn more at http://www.ASCO.org, explore patient education resources at http://www.Cancer.Net, and follow us on Facebook, Twitter, LinkedIn, and YouTube.

ABOUT AHNS

The American Head & Neck Society (AHNS) is the single largest organization in North America for the advancement of research and education in head and neck oncology. The mission of the American Head and Neck Society is: to promote and advance the knowledge of prevention, diagnosis, treatment, and rehabilitation of neoplasms and other diseases of the head and neck; to promote and advance research in diseases of the head and neck, and; to promote and advance the highest professional and ethical standards. For more information, visit http://www.ahns.info.

ABOUT SITC

Established in 1984, the Society for Immunotherapy of Cancer (SITC) is a nonprofit organization of medical professionals dedicated to improving cancer patient outcomes by advancing the development, science and application of cancer immunotherapy and tumor immunology. SITC is comprised of influential basic and translational scientists, practitioners, health care professionals, government leaders and industry professionals around the globe. Through educational initiatives that foster scientific exchange and collaboration among leaders in the field, SITC aims to one day make the word "cure" a reality for cancer patients everywhere. Learn more about SITC, our educational offerings and other resources at sitcancer.org and follow us on Twitter, LinkedIn, Facebook and YouTube.

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