The following article features coverage from the Connective Tissue Oncology Society 2021 virtual meeting. Click here to read more of Cancer Therapy Advisor’s conference coverage.

Nearly all patients with recurrent chordoma experienced clinical benefit with immune checkpoint inhibitor (ICI) treatment in a small, single-center, retrospective study. These findings were presented at the Connective Tissue Oncology Society (CTOS) 2021 Annual Meeting.

“With broadening use of immunotherapies, there may be some utility in treatment with ICIs,” said study author Andrew J. Bishop, MD, of MD Anderson Cancer Center in Houston.


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The aim of this study was to determine the response to ICIs among patients with recurrent chordoma. Researchers retrospectively evaluated 17 patients with recurrent chordoma who had received ICI therapy between 2016 and 2020. The median follow-up was 29 months.

At baseline, the median age was 63 years, and 76% of patients were male. The majority of patients were non-Hispanic White (76%), followed by 12% who were Hispanic, 6% who were Black, and 6% who were Asian. The chordoma was distant in 42% of patients, and 29% of patients each had regional or localized disease. The primary location of disease was in the sacrum in 59%, the mobile spine in 29%, and base of the skull in 12%.

Most patients received ICI treatment as their first line of therapy (59%). ICI treatment was administered as second-line therapy in 29% of patients and subsequent therapy in 12%. Pembrolizumab was the most common ICI administered (53%), followed by durvalumab plus tremelimumab (29%), FAZ053 (12%), and nivolumab plus ipilimumab (6%). Most patients also received concurrent radiotherapy. The median number of ICI cycles was 8.

The median overall survival was not yet reached, and the 1-year overall survival rate was 87%. The median progression-free survival was 14 months, and the 1-year rate was 56%.

Clinical benefit, defined as complete response (CR), partial response (PR), or stable disease (SD), was achieved by 88% of patients. This included 1 CR (6%), 3 PRs (18%), and 11 cases of SD (65%). Two patients experienced progressive disease.

Of the 4 patients who achieved a CR or PR, 3 had received pembrolizumab, and all received ICI as first-line therapy.

“Interestingly, half of these patients initially had radiographic progression following ICI initiation, but due to discordance with clinical symptoms, the ICI was continued,” Dr Bishop said.

The overall duration of response was a median of 12 months overall, 13 months in patients who achieved a CR or PR, and 6 months in patients who had SD.

ICI treatment was discontinued due to toxicity in 18% of patients, and 29% discontinued due to completion of therapy. Immune-related toxicity occurred in 47% of patients, which included 5 patients with grade 1-2 events and 3 patients with grade 3-4 events. The most common grade 1-2 events were endocrine, dermatologic, or Sicca syndrome. The most common grade 3-4 events were myocarditis, colitis, and pneumonitis.

Dr Bishop concluded that “these promising data certainly provide support for the prospective evaluation of ICIs in patients with chordoma.”

Read more of Cancer Therapy Advisor’s coverage of CTOS 2021 by visiting the conference page.

Reference

Bishop AJ. Immune checkpoint inhibitors provide favorable responses in patients with recurrent chordoma. Presented at CTOS 2021; November 10-13, 2021. Abstract 35.