Rockville, MD., November 7, 2022 OncoC4, Inc., a clinic-stage biopharmaceutical company focused on developing novel cancer immunotherapies Announced clinical and safety data from the ongoing Phase 1/2 PRESERVE-001 trial, which involves ONC-392 in combination with pembrolizumab in advanced metastatic cancer. ONC-392 is a new generation of anti-CTLA-4 monoclonal antibody that retains the CTLA-4 immune tolerance checkpoint function and is used alone or in combination with anti-PD -(L)1 therapy for the treatment of advanced solid tumors.

These data will be presented orally at the 37th Annual Meeting of the Society for Cancer ImmunoTherapy (SITC). On Thursday, November 10, 2022, at 6:30 PM, Dr. Siwen Hu-Lieskovan, Director of the Solid Tumor Program at the University of Utah Huntsman Cancer Institute, will give an oral presentation entitled "Dose escalation of next "in Room 258ABC, Boston Convention Center, USA generation Anti-CTLA-4 antibody ONC-392 in combination with fixed dose of pembrolizumab in patients with advanced solid  "tumors" report.

Dr. Pan Zheng, co-founder and Chief Medical Officer of OncoC4, said: "Data from our dose-escalation and dose-extension study show that ONC-392 in combination with pembrolizumab has a very good therapeutic index, and we are particularly encouraged by early data from our dose-expansion study in immunotherapy-resistant melanoma patients, which showed five partial responses and one stable disease in the first six evaluable patients." "

The Presert-001 trial is an open-label, multicenter Phase 1/2 clinical study (NCT04140526) evaluating the safety, pharmacokinetics, and efficacy of ONC-392 as a single agent and in combination with pembrolizumab in advanced solid tumors and NSCLC. The study was conducted at more than 40 clinical facilities in the United States and Australia, with a total of approximately 250 patients enrolled in monotherapy and combination therapy groups.

In the combination dose-climbing cohort, seven patients received 3mg/kg and six patients received 6mg/kg of ONC-392 with a standard dose of pembrolizumab every three weeks, including patients with PD-1/ CTLA4-resistant melanoma and NSCLC.

Key preliminary results from the combination therapy dose-climbing study in patients with metastatic cancer:

Of the 10 patients whose tumor response could be assessed (the best response was assessed according to RECIST 1.1), three had partial response (PR), six had stable disease (SD), and one had disease progression (PD).

In patients who could be evaluated, there was 30% ORR and 90% DCR.

Those in remission included a patient with cervical cancer who had previously failed multiple lines of chemotherapy, a patient with triple-negative breast cancer who had progressed after taking pembrolizumab and atezolizumab, And one melanoma patient who had progressed from previous 13-line systemic therapy, including ipilimumab (anti-CTLA-4) plus nivolumab (anti-PD-1) combination therapy.

Of the 13 patients who received at least one dose of combination therapy, there were three (23%) grade 3 immunotherapy-related adverse events (irAEs), with no grade 4 or 5 reports.

No dose-limiting toxicity (DLT) was observed and the maximum tolerated dose was not reached.

The recommended phase 2 dose has been established as 6mg/kg of ONC-392 in combination with 200mg of pembrolizumab. Unlike most other CTLA-4 drugs, ONC-392 was administered continuously throughout the study, with the longest dosing lasting more than a year.

Key preliminary results from an extended cohort study of combination therapy for advanced metastatic melanoma:

Of the six evaluable patients treated with 6mg/kg ONC-392 and 200mg pembrolizumab, five had active partial response (PR) and one had stable disease (SD).

All patients who achieved a partial response were patients who had previously progressed after multiline therapy, and most of them were patients whose disease had progressed after treatment with ipilimumab in combination with opdivo.

Dr. Yang Liu, CEO of OncoC4, said, "We are pleased to share positive initial results from the combination therapy portion of the PRESERVE-001 trial at the prestigious SITC annual meeting. The upcoming data and the monotherapy data presented at the same site last year give us more confidence in the potential of ONC-392 to improve the lives of patients with a variety of refractory cancers."