Carrick Acquires Rights to CT900, Plans New Trial in Ovarian Cancer Patients

Carrick Acquires Rights to CT900, Plans New Trial in Ovarian Cancer Patients

Carrick Therapeutics, a biopharmaceutical company, has acquired the rights to CT900 and plans to conduct a later-stage clinical trial to evaluate the safety and effectiveness of the investigational therapy in women with resistant or refractory ovarian cancer.

The Institute of Cancer Research (ICR) and global health company BTG, the original developers of the therapy candidate, have reached an agreement with Carrick to move CT900 to next-stage clinical trials. Under the new deal, Carrick now has exclusive worldwide rights to develop and commercialize CT900 and is already planning a trial for it.

“We’re very pleased to be partnering with Carrick to bring CT900 into the larger trials that are needed to confirm that it’s an effective drug for the treatment of some high-grade ovarian cancers,” Toby Richardson, ICR’s deputy director of enterprise, said in a press release.

CT900, created by a team from the Cancer Research UK Cancer Therapeutics Unit at ICR and formerly known as BTG945, is the first of a new class of small molecule therapies.

It mimics folic acid — or vitamin B9 — to selectively enter ovarian cancer cells, and kills them by blocking an enzyme called thymidylate synthase, which causes irreparable DNA damage.

CT900 specifically targets ovarian cancer cells, while leaving healthy cells alone, because they have an abnormally high number of cell surface receptors for folic acid, called folate receptor alpha.

The ICR, along with BTG, carried out CT900’s early development, which led to a Phase 1 trial (NCT02360345) evaluating the safety and effectiveness of CT900 — known as ONX-0801 at that time — in women with resistant or refractory ovarian cancer.

The open-label trial was conducted by a team at ICR and The Royal Marsden NHS Foundation Trust, in collaboration with Onyx Pharmaceuticals (now a subsidiary of Amgen).

Results from 15 enrolled women with advanced ovarian cancer that failed to respond to multiple lines of chemotherapy showed that the tumors in seven of the patients (47%) shrank after CT900 therapy.

CT900 was found to be safe, with none of the side effects often associated with chemotherapy, and was effective in targeting cancer cells.

During the trial, the team also discovered that high levels of alpha folate receptors in tumors were associated with better treatment responses, and that these receptors could therefore be used as a predictive biomarker of a patient’s response to CT900 therapy.

They then developed a test to detect the levels of alpha folate receptor, which can help to identify women who are most likely to benefit from CT900 treatment.

“I’m delighted that this research programme is entering a new phase, which could lead to a new drug becoming available for women with ovarian cancer who desperately need more options,” said Udai Banerji, MD, a professor of molecular cancer pharmacology at the ICR and consultant medical oncologist at The Royal Marsden, and who led the Phase 1 trial. “The fact that the drug works as a single agent and that it has a predictive biomarker of response increases its chance of success in future clinical trials.”

Carrick’s new trial will be led by Susana Banerjee, PhD, and conducted at The Royal Marsden. The hope is that if the trial provides promising results, it may be enough to gain approval for the use of CT900 in ovarian cancer patients who have limited treatment options.

Elaine Sullivan, PhD, Carrick Therapeutics’ CEO, added that “in addition to ovarian cancer, we will be investigating CT900 in other difficult to treat cancers that express high levels of folate receptor alpha.”