Pembrolizumab useful for a small number of patients with progressive metastatic adenocarcinoma or squamous cell carcinoma of the esophagus, according to a public research ph2.
"Like gastric cancer, we see that therapy with antibodies against PD-1 has a moderate activity in adenocarcinoma of the esophagus," - said Dr. Manish A. Shah in an interview with Reuters Health. "However, for patients who do respond, it is a significant and important option."
The online newspaper JAMA Oncology of December 20, Dr. Shah from Weill Cornell Medicine and New York-Presbyterian Hospital, New York, and his colleagues report on 121 patients who had three or more therapy before taking pembrolizumaba intravenously every three weeks to two years. The average number of treatment sessions was 4.0.
After an average of 5.8 months of total observation of 12 patients (9.9%) showed an objective response. This amounted to 14.3% of patients with esophageal squamous cell carcinoma and 5.2% of patients with adenocarcinoma. The response was higher in patients with PDL1-positive tumors (13.8% vs. 6.3%). In addition, in the middle of the observation 13.3 months among respondents median duration of response has not been achieved.
According to the researchers, the survival results were generally encouraging: median overall survival (OS) was 5.8 months, 6-month rate of 49% RH and 12-month rate of 28% RH. They note that it is beneficial "to the historically observed median overall survival of less than 4 months and 12-month rate of less than 13% RH in the second row."
Only five patients discontinued treatment due to adverse events. The researchers note that "where there are effective treatment options for unmet need, pembrolizumab provides long-term anti-tumor activity with manageable safety."
The research team notes that a randomized study in which pembrolizumab used as first- and second-line metastatic esophageal cancer.
Dr. Benjamin A. Weinberg of the Center for the integrated treatment of cancer Lombardi at Georgetown University, Washington, DC, said the results "support at least attempt to apply pembrolizumaba in refractory progressive esophageal cancer. The frequency of responses is very low (9.9%) , but it is still clinically significant conditions in the third line (usually you get fewer responses at each subsequent line therapy). Furthermore, 20.7% of patients had stable disease with 30.6% of the control level. "
However, he noted that the average response time was 4.1 months and the median duration of treatment was only 2.0 months, which means that patients either progressed rapidly, or need some time to get an objective answer.
Moreover, she added Dr. Weinberg, "patients in the third line often can not wait for a response within four months, because they are symptomatic because of their cancer and need to reduce the tumor as possible. In the third line without many other options for treatment with pembrolizumaba it makes sense, but immunotherapy is likely to be transferred to the second or even the first line. "