Cellectar Biosciences has seen ups and downs in the last 18 months, including several changes in its top ranks. Now, as the cancer drug developer prepares to take its lead drug candidate into mid-stage clinical trials, CEO Jim Caruso seems more interested in talking about his company’s future than its past.
Madison, WI-based Cellectar (NASDAQ: CLRB) expects a Phase 2 trial for its lead drug candidate, known as CLR 131, will begin by March, and Caruso says data from the study could “really transform the company” from where it stands today.
“We’re laser-focused on CLR 131, without question,” Caruso says in an interview at Cellectar’s offices in Madison. The drug candidate, which has the potential to treat malignant tumors and certain forms of blood cancer, including multiple myeloma, is currently in a Phase 1 clinical trial.
Cellectar’s technology is based in part on phospholipid ethers, which are designed to help kill tumors while minimizing the amount of healthy tissue destroyed in the process.
Asked to comment on Weichert’s departure and contributions to Cellectar over the years, Caruso says, “Hats off to him. He started the company [and] it’s not easy to build a company. We’re very appreciative and thankful for his contributions, and wish him the very best.”
Weichert’s exit was sandwiched between the departures of two other key leaders at Cellectar in 2016. Former vice president of business development J. Patrick Genn’s last day was March 11, according to a proxy statement from the company, and former chief medical officer Kevin Kozak left last fall. Caruso confirmed both departures, and says that Cellectar currently has 15 employees.
But in the time since Caruso came aboard, in June 2015, his company has had occasional good news to report. Cellectar has made strides on the intellectual property front. And in August, the National Cancer Institute awarded the company a $2 million grant for the Phase 2 clinical trial of CLR 131.
Caruso says his company is “really excited” with the results it has seen from the drug’s Phase 1 trial up to this point. Cellectar views the responses of four patients among the eight that made up the study’s first two cohorts as more favorable than the other four patients’ responses, he says. Every one of what Caruso calls the four “best” patients in the first two cohorts met the threshold of partial response, the marker of efficacy in a clinical trial, within 85 days of being dosed with CLR 131, according to company materials.
Caruso says he believes the data could look even better on patients in the third cohort of the Phase 1 trial, which is currently enrolled. There is also the possibility that administering multiple doses of the drug over time could produce better results, Caruso says. In the Phase 2 study, investigators will have the option of giving patients a second dose between 75 and 180 days after the first one, he says.
“Patients are going to get potentially … four times the drug [as those in the first cohort of Phase 1],” Caruso says. “We know that it’s tolerable. Your hope is with the increased amount of drug, you get a synergy or greater efficacy.”
Besides kicking off the Phase 2 clinical trial of CLR 131 and providing an update on the Phase 1 study’s current cohort, Cellectar also plans to, by June, report on the progress of its partnership with Pierre Fabre. The collaboration is aimed at combining compounds using cancer-killing agents called “cytotoxics” developed by the French company with Cellectar’s drug delivery technology to construct new compounds.
The Pierre Fabre partnership can be seen as encapsulating Cellectar’s shift in strategy away from diagnostics and toward drugs under Caruso.
The company’s phospholipid ether-drug conjugate platform, which is designed to work with a variety of drugs to kill cancer cells and spare healthy ones, sets Cellectar apart from “other small oncology shops,” Caruso says.
“We have a delivery vehicle that we can add any number of payloads to, and create new drugs and intellectual property,” he says. “We want to get to a point where we can conjugate to our delivery vehicle reasonably quickly, and then find out in a shorter period of time whether or not you have an opportunity for a drug. It allows us to be more cost-efficient, and get more done quicker.”