Nivolumab is not an effective single-agent treatment for patients with advanced uterine leiomyosarcoma that progresses after at least 1 prior line of therapy, according to a study published in Cancer.1

Uterine sarcoma, which make up about 3% of uterine cancers, often display infiltration of tumor-associated macrophages, which may explain suppression of T cell function. For this phase 2 trial, researchers evaluated whether nivolumab, an immune checkpoint inhibitor, would effectively treat patients with uterine leiomyosarcoma who progressed after at least 1 prior therapy line.

Of 12 enrolled patients, 4 had 1 prior treatment line, 2 had 2 prior treatment lines, and 6 had at least 3 prior treatment lines. All patients were previously treated with a gemcitabine-based regimen.

All patients received nivolumab 3 mg/kg intravenously on day 1 of 2-week cycles. Nine patients discontinued treatment for disease progression, 1 patient had unconfirmed progression, and 2 patients discontinued at investigator’s/patient’s decision.

The objective response rate was 0%.

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Grade 3 or worse toxicities “definitely” related to treatment included increased serum amylase and increased lipase.

The authors concluded that although nivolumab did not induce a response in any of these patients, the presence of tumor-associated macrophages in this setting may be a promising treatment avenue for novel combinations.

Reference

  1. Ben-Ami E, Barysauskas CM, Solomon S, et al. Immunotherapy with single agent nivolumab for advanced leiomyosarcoma of the uterus: results of a phase 2 study. Cancer. 2017 Apr 26. doi: 10.1002/cncr.30738 [Epub ahead of print]