Surgery is the primary treatment for a large number of solid cancers, but the disease often comes back because surgeons miss tiny clusters of cells not seen during the procedure or in pre-operative images.
Now, the U.S. Food and Drug Administration has granted Fast Track status to a new molecule designed to “light up” cancer cells, so that surgeons can see tiny cancer clumps, or which lymph nodes are affected by tumor cells. If approved, OLT38 could significantly improve outcomes for ovarian and other cancer patients who undergo surgery as their primary care.
“This has the potential to save lives because the surgeons will tell you that the only sure way to cure cancer is to cut it all out,” Philip Low, Purdue’s Ralph C. Corley distinguished professor of chemistry, director of the Purdue Institute for Drug Discovery, who developed that OTL38 molecule, said in a press release. “This technology gives them a significantly better chance to find and remove all the cancer from a patient.”
Nearly 40 percent of tumors come back after surgery because surgeons miss microscopic clusters of 10 or 20 cells that are not seen in pre-operative images or during surgery. OTL38 is a compound that links a folic acid molecule, specific to tumor cells, to a near-infrared dye. The dye is injected two hours before surgery, and is designed to bind to the diseased tissue.
Fast Track status was supported by results of a Phase 2 trial of OTL38 in 48 ovarian cancer patients (NCT02317705), which showed that 96 percent of the illuminated tissue was cancerous, and 98 percent of the malignant lesions “lit up” with the molecule.
“Those are remarkable numbers,” Low said. “That high specificity was likely a key to the FDA’s decision.”
Together with the CTL38’s Orphan Drug designation, which is granted to compounds that may treat rare conditions or diseases, the new designation will speed the development of the compound and its implementation in Phase 3 clinical trials.
“When there are fewer than 200,000 patients diagnosed with a disease, there aren’t a lot of incentives for a company to develop treatment,” Low said. “This orphan drug status provides that incentive to move your drug quickly into an area where an important need is not met.”
A Phase 3 trial evaluating OTL38 in ovarian cancer patients is planned to begin by the end of the year, and earlier-stage trials are being designed to assess the safety and efficacy of OTL 38 in lung, kidney, and brain cancers.
Low’s company, On Target Laboratories, is also developing a new compound that lights up cancer cells buried beneath tissue that would likely be missed during surgery. This dye may have the ability to reduce the amount of brain tissue that needs to be excised to remove cancer cells.