Conference Coverage

Trastuzumab plus chemo shows efficacy for high HER2 endometrial cancer



– Adding the anti-HER2 antibody trastuzumab to a standard chemotherapy regimen produced markedly improved responses among patients with an advanced stage or recurrent uterine serous carcinoma that also overexpressed the HER2/neu cell receptor protein in a controlled, multicenter, phase 2 study with 58 evaluable patients.

The 30 patients who received trastuzumab along with carboplatin plus paclitaxel had a median progression-free survival of 12.6 months compared with 8.0 months among the 28 control patients who received only carboplatin plus paclitaxel, a hazard reduction of 56% with trastuzumab that was statistically significant (P = .0052), Alessandro D. Santin, MD, said at the annual meeting of the Society of Gynecologic Oncology.

In the subgroup of 41 patients with advanced (not recurrent) uterine serous carcinoma (USC) the incremental difference in median progression-free survival among patients treated with trastuzumab was 8.6 months, based on a 17.9-month duration in the 20 patients who received trastuzumab and 9.3 months in 20 control patients on chemotherapy only (P = .013).

Dr. Alessandro D. Santin, professor of ob.gyn. and co-chief of gynecologic oncology at Yale University in New Haven, Conn. Mitchel L. Zoler/MDedge News

Dr. Alessandro D. Santin

“We have never before seen an 8.6 month increase in progression-free survival among patients with such a poor prognosis. This is practice changing,” declared Dr. Santin, professor of ob.gyn. and co-chief of gynecologic oncology at Yale University in New Haven, Conn. He expressed hope that based on these findings the regimen of trastuzumab plus carboplatin and paclitaxel will soon appear in U.S. cancer-treatment guidelines, thereby making it more likely that health insurers will cover the cost of trastuzumab treatment for these patients.

“We’ll push to have the trastuzumab, carboplatin, and paclitaxel regimen in the guidelines” for treating patients with USC that overexpresses HER2/neu, agreed Amanda N. Fader, MD, director of gynecologic oncology at Johns Hopkins Medicine in Baltimore and lead author on the study reported by Dr. Santin.

Shortly after Dr. Santin’s report at the meeting, the results appeared in an article published online March 27 in Journal of Clinical Oncology.

The phase 2 trial ran at 11 U.S. centers during 2011-2016, and randomized 61 patients with stage III or IV or recurrent USC and high HER2 protein expression measured by immunohistochemistry and amplification of the HER2 gene shown by fluorescence in situ hybridization. The researchers collected data from 58 treated patients. Among the 17 patients with recurrent disease, those who received trastuzumab had a median progression-free survival of 9.2 months compared with 6.0 months in the controls, a hazard reduction of 86% with trastuzumab that was statistically significant (P = .0029). The addition of trastuzumab to carboplatin and paclitaxel was well tolerated.

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