Two new studies published in Nature Communications indicate that immunotherapy may benefit people with leptomeningeal carcinomatosis, a rare but serious complication of cancer that has spread to the brain and/or spinal cord.
Approximately 5% to 8% of all patients with cancer develop leptomeningeal carcinomatosis—tumors in the leptomeninges and cerebrospinal fluid—after first being diagnosed with breast cancer, lung cancer, melanoma, or other malignancies. Current treatment options rarely benefit patients with leptomeningeal carcinomatosis, and there is an urgent need for new therapies.
Immune checkpoint inhibitors are important medications that boost the immune system’s response against various cancers, but their effects against leptomeningeal carcinomatosis are unclear. To investigate, researchers conducted two phase II clinical trials.
Study Findings
In the first article, published by Prakadan et al, researchers collected and analyzed immune cells and cancer cells from the cerebrospinal fluid of patients in the trials both before and after treatment with immune checkpoint inhibitors. Researchers found signs that the therapy was having an effect; for example, the number of certain cancer-killing immune cells and the expression of particular genes within cells were higher following treatment.
The second article, published by Brastianos et al, presents the results of a study that evaluated 18 patients with leptomeningeal carcinomatosis who received combined ipilimumab and nivolumab until disease progression or unacceptable toxicity. The primary endpoint was overall survival at 3 months, and 8 of the 18 patients were alive at that time—historically, patients survive for a median of 3 to 7 weeks after being diagnosed with leptomeningeal carcinomatosis. One-third of patients experienced one or more serious adverse events. Two patients discontinued treatment due to unacceptable toxicity. The most frequent adverse events included fatigue, nausea, fever, anorexia, and rash.
The authors noted that larger, multicenter clinical trials are needed to validate their results.
Priscilla K. Brastianos, MD
“In these two published studies, we demonstrated—in patients through a clinical trial and microscopically in the laboratory—that immune checkpoint blockade has promising activity for patients with leptomeningeal carcinomatosis. More data are needed, but this is an exciting first step toward showing that immune checkpoint blockade may have a role in treating this devastating disease,” said study coauthor Priscilla K. Brastianos, MD, Director of the Central Nervous System Metastasis Center at Massachusetts General Hospital and Associate Professor of Medicine at Harvard Medical School.
Disclosure: For full disclosures of the study authors, visit nature.com/ncomms.
