Mateon Therapeutics Announces Results from Second Interim Analysis of CA4P Phase 2/3 FOCUS Study

Mateon Therapeutics, Inc. recently announced results from its second scheduled interim analysis of the ongoing Phase 2/3 FOCUS study evaluating CA4P in combination with bevacizumab (Avastin) and physician’s choice chemotherapy in patients with platinum-resistant ovarian cancer (prOC).

FOCUS is designed to evaluate whether the addition of CA4P improves progression-free survival (PFS), the primary endpoint of the study, as well as objective response rate (ORR) and other measures. All patients enrolled in the FOCUS study are receiving either CA4P or placebo plus the current standard-of-care for platinum-resistant ovarian cancer, bevacizumab (Avastin) and chemotherapy. The current interim analysis is based on initial results from the first 40 patients (19 with CA4P, 21 with placebo) in the study who have been treated for at least 2 months or discontinued from the trial. A total of 91 patients have been enrolled in the Phase 2 portion of FOCUS. The next (third) interim analysis will be conducted when approximately ¾ of the enrolled patients (originally targeted at 80) have been treated for at least 2 months or discontinued from the study.

“We are encouraged that early data on the primary endpoint of the study continue to favor CA4P and that our investigational drug remains well tolerated,” said William D. Schwieterman, MD, President and Chief Executive Officer. “There is a large unmet medical need in the ovarian cancer market as patients with prOC have low survival rates and few treatment options. We look forward to additional and more mature data from the third interim analysis expected just over 1 month from now – in this upcoming analysis, we will have more data on the current patients, who will have had additional time under treatment, as well as initial efficacy and safety information on approximately 25 additional patients.”

PFS, the primary endpoint of the study, continues to favor the CA4P group, with a 1.68-month increase in median PFS for the patients receiving CA4P compared to control (6.64 months vs. 4.96 months; HR=0.68; p=0.456). Progression events are available from 16 of 40 (40%) patients: six patients (31.6%) in the CA4P arm and 10 (47.6%) patients in the control arm progressed or died while in the study.
Partial responses were observed in 4 of 16 (25.0%) patients treated with CA4P and 6 of 19 (31.6%) patients treated with the control regimen. Stable disease was observed in 9 of 16 (56.3%) patients treated with CA4P compared to 11 of 19 (57.9%) patients treated in the control arm.

CA4P continues to show a favorable safety profile. Most patients receiving CA4P experienced transient increases in blood pressure (BP) compared to the control arm (57.9% vs. 9.5%, respectively). BP increases generally peaked 2 hours following treatment and normalized without clinical sequelae 2 to 3 hours later. Rates of grade 3 hypertension were similar between the treatment and control arms (21.1% vs. 23.8%). There was one case of grade 4 hypertensive crisis in the CA4P arm. Adverse events that occurred in >25% of patients and more frequently in the treatment arm included nausea, fatigue, cough, and hypertension, most of which were mild to moderate in severity. Rates of neutropenia, anemia, and thrombocytopenia were low and similar between treatment arms.

Mateon Therapeutics, Inc. is a biopharmaceutical company seeking to realize the full potential of vascular targeted therapy (VTT) in oncology. VTT includes vascular disrupting agents (VDAs), such as the investigational drugs that Mateon is developing, and anti-angiogenic agents (AAs), a number of which are FDA-approved and widely used in cancer treatment. These two approaches have distinct yet complementary mechanisms of action.

Mateon believes it can significantly improve cancer therapy by employing these two complementary approaches simultaneously. When utilized this way, VDAs obstruct existing blood vessels in the tumor leading to significant central tumor cell death while AAs prevent the formation of new tumor blood vessels. Mateon is committed to leveraging our intellectual property and the product development expertise of its highly skilled management team to enable VTT to realize its true potential and to bring much-needed new therapies to cancer patients worldwide.