Last week we caught up with Dr. Sylvia Lee for an update on SCCA’s newly launched TIL therapy program. TIL therapy (TIL is short for tumor-infiltrating lymphocytes) is a type of treatment that’s currently being evaluated in a clinical trial at SCCA for patients with advanced melanoma.
Tumor-infiltrating lymphocytes are T-cells that surround the melanoma cells and are part of the body’s immune system that can recognize and attack cancer. However, melanoma creates an immunosuppressive environment that turns TIL cells off before they can eradicate the tumor. TIL therapy begins with surgically removing a portion of the melanoma tumor to extract the TIL that are growing within the tumor mass. Then, at a laboratory over at the Hutch, the cells are switched back on using IL-2 (Interleukin 2) and grown for 3-5 weeks. At this point, the lab tests the cells against the patients’ preserved tumor, and selects the TIL cells that are best at recognizing and attacking the tumor. These selected TIL are then grown out into the billions and infused back into the patient.
Dr. Lee, a medical oncologist and researcher, is the principal investigator for SCCA’s TIL trial. She says that the response rates for TIL therapy at other centers is about 50%—a rate that she characterizes as “pretty high.” The complete response rate—in which all the cancer has disappeared on a CT scan—has been observed at 12% in early trials. The majority of patients with a complete response have not relapsed, with follow up as long as 8 years. That’s significantly better than the responses for other FDA-approved melanoma treatments, including ipilimumab and vemurafenib, and it’s especially encouraging since patients who go on TIL have often failed these other therapies.
TIL generation typically takes 6-7 weeks from start to finish, and TIL cells can be frozen at a midway point, for future use if the patient is not quite ready for treatment. Says Dr. Lee, “It’s complicated, and not just the TIL generation, but lining everything up, finding patients who need treatment but are healthy enough to participate in the clinical trial, making sure we have insurance approval for their trial participation, planning the timing of TIL infusion in the context of the patient’s clinical picture.”
SCCA is one of four centers in the United States that’s offering TIL. Other centers include the NIH/NCI in Maryland, MD Anderson in Texas, and Moffitt Cancer Center in Florida. Dr. Lee’s program started late last summer and so far has recruited six patients, all at various points in the treatment process. She hopes to start seeing early results by this summer. See the SCCA website for information about TIL and other immunotherapies that are being offered for melanoma patients at SCCA. See also SCCA’s TIL clinical trial page, which lists eligibility criteria for prospective patients. Finally, this NCI Cancer Bulletin includes even more information about TIL therapy.