An unmet need
“Leptomeningeal metastasis is a strong unmet need, although its occurrence is fortunately quite rare,” commented, a clinical professor and medical oncologist at City of Hope National Medical Center in Duarte, Calif., who was not involved in this study.
The trial is noteworthy for showing activity of programmed death–1 (PD-1) blockade given only systemically and not with additional intrathecal therapy (as has been done in a concurrent study at MD Anderson Cancer Center) and for providing insight into various biomarkers, Dr. Margolin said in an interview.
“I cannot take a stand on author conclusions other than to agree it warrants further evaluation in carefully selected patients, and it would be great to compare something like peripheral PD-1 blockade alone versus in combination with intrathecal therapy versus a combination such as CTLA4 blockade plus PD-1 blockade such as our group and others have shown to have increased activity in CNS metastases over PD-1 block alone,” Dr. Margolin said.
“The drugs in this class are already approved, so there is no reason not to try them,” she noted.
However, patients with leptomeningeal metastases of melanoma, for example, are likely to have already received anti-PD-1 immunotherapy.
“So the settings in which off-the-shelf PD-1 blockade would be useful are extremely limited,” she concluded.
The current trial was funded by Merck, the National Institutes of Health, the Lung Cancer Foundation of America, the International Association for the Study of Lung Cancer, and Johns Hopkins University Seed Grants. Dr. Naidoo disclosed relationships with AstraZeneca, Merck, Bristol Myers Squibb, and Roche/Genentech. Dr. Margolin disclosed no relevant conflicts of interest.
SOURCE: Naidoo J et al. SITC 2020, .