Cellectar says tumors shrank as much as 90 percent in early trials of its lead cancer drug
Cellectar Biosciences, a Madison company working on cancer-fighting medications, is cheering early patient test results of its main compound, but it has ended production of the drug here, cutting jobs, and last week the company learned its supply of the drug has been temporarily halted by federal regulators.
CLR 131, Cellectar’s lead drug candidate, is being tested on patients with recurrences of a variety of blood cancers, including multiple myeloma and several types of lymphoma, in a phase 2 trial.
Initial results in patients with diffuse large B-cell lymphoma, show that after a single dose of CLR 131, 33 percent of the patients saw their tumors reduced, in amounts ranging from 60 percent to more than 90 percent. The company did not say how many people were in that group. Half of the participants had some tumor shrinkage or their conditions were stabilized after receiving the medication.
“We are very encouraged by the strong response rates and meaningful reductions in tumor volumes,” Cellectar CEO James Caruso said.
In a companion report, the company said a woman with Waldenstrom macroglobulinemia, a rare form of non-Hodgkin’s lymphoma, who received one dose of CLR 131 had more than a 50 percent reduction in her tumors when she was tested 52 days later. She received a second dose 10 weeks later, and after two months, a scan showed her tumors were 94 percent smaller, with four of five tumors gone.
It was a “very dramatic response,” said Dr. Sikander Ailawadhi, the physician who treated the woman at The Mayo Clinic in Jacksonville, Florida. But, he added, it is too soon to tell how long the response will last or if there are long-term side effects.
Even though the initial results involve a small number of patients, they are noteworthy, said Cellectar chief medical officer Dr. John Friend. They show potential investors and the public that CLR 131 has “a significant impact across a variety of hematological cancers,” including “hard-to-treat, highly aggressive lymphomas,” he said.
The phase 2 study is being conducted at 10 cancer centers around the U.S. and is expected to involve as many as 80 patients. If the tests continue to go well, Cellectar could apply for U.S. Food and Drug Administration approval by 2022, Friend said.
A study will begin this fall on the drug’s impact on pediatric tumors, and in 2019, in a collaboration with the UW-Madison’s Carbone Cancer Center, it will be tested along with radiation for treating recurring head and neck cancer.
Cellectar also said it is teaming with a French biotech, Orano Med, to see if a combination of the two companies’ technologies will produce an even more effective tool to stop cancer.
Orano Med’s CEO Julien Dodet said combining the two technologies has “great potential to improve patient outcomes by having a better efficacy and safety profile than other technologies.”
Meanwhile, Cellectar staged a reverse stock split in mid-July, offering one share of common stock for every 10 shares stockholders had, then two weeks later, the company sold more stock to raise money. The secondary stock offering sold 1.35 million shares of common stock at $4 per share and 1,114 shares of convertible preferred stock at $10,000 per share, resulting in net proceeds to the company of about $15 million, chief financial officer Brian Posner said.
As clinical trials have ramped up, Cellectar moved production of CLR 131 to the Centre for Probe Development and Commercialization (CPDC) in Hamilton, Ontario, Canada in December 2017, saying CPDC and other third-party manufacturers can better supply large-scale amounts of the substance. Cellectar’s radiopharmaceutical manufacturing facility in Madison, where CLR 131 had been made on a small scale, was shut down earlier this year, ending about six jobs, Posner said.
He said the company currently has about 10 employees at its offices at 3301 Agriculture Drive.
On Wednesday, though, Cellectar was told the FDA has issued an “import alert” on CPDC, which means its products cannot enter the U.S. The ban resulted from an FDA inspection of the Canadian facility in March, Cellectar’s Friend said. While the deficiency does not involve CLR 131, the prohibition is on all of CPDC’s products, Friend said.
He said that won’t affect patients already in Cellectar’s clinical trials of CLR 131 but it will impact enrollment of additional patients. Friend said representatives of CPDC and the FDA are scheduled to meet Sept. 11 to discuss the situation.