Docs Hope TIL Improves in Several Ways
Although the TIL technology is a breakthrough, “we hope to see even better efficacy and lower toxicity as further research looks at ways to improve on the current TIL standard,” Dr. Puzanov said.
More research and dose adjustments may impact patient costs and side effects, he noted. “I am looking to see TILs used in the front line, with or without checkpoint inhibitors.”
Research is needed to explore how to lower the chemotherapy doses and possibly the associated toxicity, he added. Finally, researchers must consider whether high-dose IL-2 therapy — given as part of the TIL cell therapy — could be replaced with other cytokines, or whether the number of doses could be lowered. Another avenue of exploration is engineering genes for cytokines into TILs, he said.
“The key is to think about TIL therapy before you need it — ideally, when the patient is still doing well on their frontline checkpoint inhibition immunotherapy,” Dr. Puzanov said in an interview. That is the time for evaluation, and specialty centers can provide an expert assessment, he said.
“We are constantly working to improve TIL therapy,” Dr. Betof Warner told this publication. More research is needed optimize the regimen to reduce side effects, which would not only make treatment easier for currently eligible patients, but might allow treatment for patients not currently eligible.
“For example, we are looking for ways to reduce the dose of preparative chemotherapy, which prepares the body for the cells to maximize their longevity and efficacy, and to reduce or eliminate the need to give IL-2 after the cell administration,” continued Dr. Betof Warner, who is also Director of Melanoma Medical Oncology, Director of Solid Tumor Cellular Therapy, and Codirector of the Pigmented Lesion and Melanoma Program at Stanford University. “We are also actively studying next-generation TIL therapies to try to increase the efficacy.”
“Lifileucel has about a 30% success rate for melanoma that has progressed after standard therapy; we are working hard to do better than that,” she noted.
In a press release, Iovance summarized the results of the trial that supported the FDA’s accelerated approval of lifileucel. In an open-label single-arm study, including multiple sites worldwide, 73 adults with unresectable or metastatic melanoma who had received at least one previous systemic therapy underwent a lymphodepleting regimen followed by treatments with fludarabine and aldesleukin. Patients then received lifileucel at a median dose of 21.1 x 109 viable cells; the recommended dose ranges from 7.5 x 109 to 72 x 109 cells.
The primary efficacy outcome was objective response rate (ORR). The ORR in the study was 31.5%, and the median time to initial lifileucel response was 1.5 months.
The clinical trials of lifileucel for which Dr. Betof Warner and Dr. Puzanov served as investigators were sponsored by Iovance.