Aggressive anal cancer responds to immunotherapy drug

Researchers have reported results of the first-ever phase II clinical trial results for treatment with the immunotherapy drug nivolumab on squamous cell carcinoma of the anal canal (SCCA), a rare malignancy that is on the rise.

The phase II study was designed and led by researchers with MD Anderson Cancer Center's Human Papillomavirus-Related (HPV) Cancers Moon Shot Program. MD Anderson enrolled 18 patients who volunteered to provide both pre- and post-treatment tissue samples. The study revealed encouraging correlations between immunologic biomarkers and responses to treatment.

“There have been no standardized treatment options for metastatic SCCA patients,” said Van Morris, M.D., assistant professor of Gastrointestinal Medical Oncology. “This study demonstrated responses in five of 18 patients treated at MD Anderson, and many of the patients had significant reductions in their tumor size.”

The findings were recently presented at American Association for Cancer Research’s annual meeting in New Orleans.

“In this first prospective phase II trial for refractory metastatic SCCA, our exploratory analysis of pre- and on-treatment tissues samples revealed potential correlations between immunologic biomarkers and clinical outcomes to nivolumab,” said Cathy Eng, M.D., professor of Gastrointestinal Medical Oncology and national study principal investigator.

Metastatic SCCA, a cancer often associated with HPV infection, is normally treated with chemotherapy, although no trials have established a standard of care.

The study employed the monoclonal antibody nivolumab, one of the drugs represented among the growing arsenal of immunotherapy therapies. The drug frees the immune system to attack cancer by disrupting a brake that halts immune response.

“This the first formal clinical trial completed with patients with previously treated metastatic SCCA,” said Morris. “In this trial, patients received a biopsy just before being treated with nivolumab and then a second paired biopsy after two doses.”

For more on the results of the study, visit MD Anderson's website.