Update on FOCUS Trial of CA4P in Ovarian Cancer Expected in Late Summer

Update on FOCUS Trial of CA4P in Ovarian Cancer Expected in Late Summer

Second preliminary results from the FOCUS Phase 2/3 trial assessing the safety and effectiveness of Mateon Therapeutics’ drug candidate CA4P in combination with standard-of-care therapies for platinum-resistant ovarian cancer are expected in coming months, the company announced.

CA4P (combretastatin a4-phosphate), also known as fosbretabulin, was designed to target blood vessels and blood supply within tumors. This investigational drug is expected to deprive cancer cells from oxygen and nutrients, triggering their death.

Mateon is currently sponsoring the Phase 2/3 FOCUS trial (NCT02641639) in platinum-resistant ovarian cancer patients. This multicenter, randomized study is expected to include about 430 patients who will receive CA4P or placebo in addition to the current standard-of-care therapy, which includes Avastin (bevacizumab) plus a chemotherapy chosen by the physician.

Preliminary data released in April, obtained from the first 20 patients enrolled in the trial, showed positive results. Among the nine patients in the CA4P arm, two, or 22%, had partial responses, showing lesion size reduction of about 76% and 64%. Among the 11 placebo-treated patients, only one (9%) had a partial response, with a lesion reduction of 46%.

In addition, the two patients receiving the investigational drug plus standard-of-care showed size reductions in lesions of about 76% and 64% compared to 46% tumor size reduction in the patient in the control arm. CA4P was shown to be well tolerated, with no significant treatment-related adverse effects being reported.

The FOCUS trial has already enrolled 57 participants and is currently enrolling patients at 37 sites in the U.S., Belgium, and Germany.

Mateon expects to release data from the second interim analysis in August, obtained from the first 40 patients treated for at least two months. Depending on the progression of the enrollment process, a third interim analysis, including data from about 60 patients, is expected to be completed in late September this year.

The company has also provided an update on another Phase 1b/2 trial testing CA4P in combination with the TKI-inhibitor Votrient (pazopanib).

The investigator-sponsored PAZOFOS trial (NCT02055690), conducted in the the U.K. in advanced recurrent ovarian cancer, is planned to include 120 patients. The study is currently enrolling and has already treated 20 patients.

The Christie NHS Trust, which is sponsoring the trial, has temporarily suspended enrollment due to two recently reported serious adverse events. One case of hypertension and myocardial ischemia, and another of chest pain, were of short duration and the symptoms were resolved. These events are currently under review.

Preliminary safety results have showed that CA4P can cause an acute and transient blood pressure increase after administration. These effects, combined with those of Votrient, whose label contains warnings of possible cardiac dysfunction, arterial thrombotic events, and hypertension, may in part explain the serious events reported.

“The investigator-sponsored PAZOFOS study, which uses CA4P with a different combination of drugs for recurrent ovarian cancer, also holds significant potential for patients and we’re hopeful that enrollment will resume soon,” William D. Schwieterman, MD, president and CEO of Mateon, said in a press release.