Kite Cancer Therapy Responses in Solid Tumors Sustained in Trialby
T-cell treatment shrinks tumors in 3 of 14 patients in test
Biotech firm licensed therapy from National Cancer Institute
A cancer therapy licensed by Kite Pharma Inc. continued to be safe and show durable responses against solid tumors for some patients in an early-stage trial run by the U.S. National Cancer Institute.
In a trial of 14 patients who received different doses, three patients’ cancers have shrunk partially, according to a study presented Sunday at the American Association for Cancer Research’s conference in New Orleans. The researchers had presented initial positive data in November, and the updated study shows that the three partial responses were durable, with one cervical cancer patient’s response continuing at 15 months.
Genetically engineered T-cell therapies are an emerging form of cancer treatment in which patients’ immune cells are modified to recognize specific markers found on cancer cells. While T-cell therapies have shown dramatic results in blood cancers, solid tumors are trickier because the markers targeted by most experimental treatments are also found on normal tissue, meaning healthy cells would also be attacked.
Kite’s therapy targets a protein called MAGE-A3, which is found during fetal development but not in normal adult tissue. It resurfaces in many cancers, making it a unique marker for tumor cells.
“MAGE-A3 is expressed in up to 30 percent of a variety of cancer types, such as melanoma, esophageal, urothelial and cervical cancers,” said Steven Rosenberg, senior author of the study and chief of the surgery branch at the National Cancer Institute. “This treatment if effective can potentially apply to a significant portion of cancer patients.”
Kite has licensed the therapy from the National Cancer Institute. The Santa Monica, California-based company has said it will file an investigational new drug application with the Food and Drug Administration by the end of the year so it can begin company trials.
Rosenberg’s team also chose to modify a type of immune cell called CD4, rather than a more commonly engineered type of cell, called CD8, that can kill tumor cells directly.
CD4 cells, known as “helper cells,” act indirectly by sending signals to activate the rest of the immune system. This trial is the first to try modified CD4 cells against metastatic cancer, Rosenberg said, and may open up a new avenue for T-cell immunotherapies.