On April 14, shares of Iovance Biotherapeutics jumped 17%, thanks to three magic words in the title of an abstract the company said will be presented at this week’s virtual meeting of the American Association for Cancer Research (AACR): “durable complete responses.”
The study, which will be discussed Tuesday morning, is a phase 1 clinical trial of Iovance’s highly anticipated tumor-infiltrating lymphocyte (TIL) product in non-small cell lung cancer (NSCLC). How durable were those responses? The abstract, released over the weekend, provides some clues.
Data from the study, being conducted at the H. Lee Moffitt Cancer Center, included results from 18 of 20 NSCLC patients treated with Iovance’s TILs after having received Bristol Myers Squibb’s checkpoint inhibitor Opdivo. Two of the patients had complete responses to the therapy that are ongoing one year later, according to the abstract. Three other patients developed new lesions after undergoing the TIL therapy but went into remission after they received tumor-directed treatments.
TILs are personalized cell treatments made from immune cells that have a natural ability to invade and kill cancer cells. Iovance’s technology involves taking T lymphocytes from patients, expanding them into the billions, and then infusing them back into the body.
Iovance’s most advanced TIL, called lifileucel, is in pivotal trials in melanoma and cervical cancer, with FDA filings expected sometime this year. The company has simultaneously been investigating the potential of TILs in lung cancer and several other tumor types, including cervical cancer and head and neck tumors.
Because Iovance is considered a leading player in TIL technology, its investors tend to jump on any news that hints at the effectiveness of the technology. Last year, its shares rocketed up on news that its TILs produced a 44% response rate and 89% disease control in ovarian cancer. Earlier this year, Iovance’s stock rose 40% on rumors that it was exploring acquisition offers.
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The small study of Iovance’s TILs released at AACR has already raised some questions that will be hard to answer until data emerge from larger trials. Among the enrolled patients, 13 progressed on Opdivo and were given subsequent treatments combining two chemotherapy drugs with IL-1. Thus, “it seems difficult to put any benefit specifically down to Iovance’s TILs,” said an analyst from Evaluate Vantage in a recent posting.
Analysts from Jefferies pointed out in a note issued Monday that the median shrinkage of tumors observed in the study to be presented at AACR was 38%, but that the researchers did not disclose the objective response rate (ORR). "We think this means that least half of the patients observed a partial response, but we caution that we don't know if these are confirmed responses. We think anything greater than 20% ORR would be clinically meaningful," Jefferies said.
Iovance’s technology was originally developed at the National Cancer Institute and has so far shown the most promise in melanoma. Some patients involved in early trials have continued to respond to the therapy for more than a decade. So it’s no surprise Iovance has been investing heavily to prepare for the launch of lifileucel in melanoma: Last year, it announced a $75 million investment in a manufacturing facility in Philadelphia.
Meanwhile, Iovance continues to work with research partners to investigate the potential of TILs in other cancers and to improve upon the first generation of the product. Iovance teamed up with the University of Texas MD Anderson Cancer Center in 2017 to study TILs in several tumor types. And in January of this year, it licensed technology from Cellectis that it will use to genetically modify TILs in the hopes of improving their potency, the company said at the time.