— APX005M and Nivolumab Combination was Well Tolerated and Induced Promising Response Rates in Patients with Metastatic or Unresectable Melanoma Progressing on Anti-PD-1/PD-L1 Therapy —

— Plenary Session and Late-breaking Poster Presentations Highlight Progress Developing APX005M in Combination Therapy for Difficult-to-Treat Types of Cancer —

SAN CARLOS, CA, USA I April 1, 2019 I Apexigen, Inc., a clinical-stage biopharmaceutical company, today presented new clinical data on APX005M at the American Association for Cancer Research (AACR) Annual Meeting, taking place March 29 – April 3, 2019 in Atlanta, GA. Apexigen’s lead immuno-oncology (I-O) therapeutic APX005M, a monoclonal antibody targeting CD40, is being evaluated in multiple ongoing clinical trials in different types of solid tumors.

“We are excited to have new clinical data presented at AACR on our CD40 antibody APX005M in combination therapy, highlighting the breadth of our clinical development program targeting difficult-to-treat types of cancer,” said Ovid Trifan, M.D., Ph.D., Chief Medical Officer and Senior Vice President of Clinical Development of Apexigen. “Yesterday, clinical data in metastatic pancreatic cancer were presented in a plenary session, showing APX005M in combination therapy was well-tolerated and induced promising tumor shrinkage in 20 of 24 evaluable patients. Today, we are presenting clinical data from our ongoing Phase 1b/2 clinical trial in patients with metastatic melanoma demonstrating that APX005M is well tolerated in combination with nivolumab and triggers responses in patients who have progressed on anti-PD-1 therapy. Together, these data speak to the promise of APX005M and we are encouraged by these early results. We look forward to continuing to advance our broad clinical development program for this therapy as a new treatment option for patients living with cancer.”

“If a patient with metastatic melanoma does not respond to currently approved immune checkpoint inhibitors, there are no approved treatment options left, unless the tumor has a BRAF mutation,” said Harriet Kluger, M.D., Professor of Medicine at Yale Cancer Center. “We are eager to assess whether combining APX005M with nivolumab can reverse the course of this disease for these patients.”

About the Phase 1b/2 Clinical Trial
The Phase 1b dose-escalation portion of this clinical trial included patients with metastatic melanoma who had progressed when previously treated with anti-PD-1 therapy. Progression was documented by two consecutive tumor assessments at least four weeks apart.  Patients were treated with 3 dose levels of APX005M (0.03, 0.1 and 0.3 mg/kg) combined with a fixed dose of nivolumab (360mg) every 3 weeks. The primary endpoint was to evaluate safety as well as to determine the maximum tolerated dose (MTD) and recommended Phase 2 dose (RP2D) of APX005M in combination with nivolumab. Nivolumab was provided by Bristol-Myers Squibb under a clinical supply collaboration agreement.

In the Phase 1b portion of this clinical trial, APX005M was well tolerated and no dose-limiting toxicities (DLTs) were observed. The RP2D for APX005M is 0.3 mg/kg. Of the 5 subjects with metastatic melanoma, 1 had a confirmed partial response (PR), 2 had prolonged stable disease (SD) (>8 months), and 2 had progressive disease (PD) as the best overall response.

The Phase 2 dose-expansion portion of this clinical trial followed a Simon 2-stage design and included two parallel cohorts of patients treated with the RP2D of APX005M with nivolumab. The primary endpoints are safety and overall response rate (ORR) measured by RECIST 1.1 criteria. Secondary endpoints include determining the pharmacokinetic (PK) profile of APX005M, assessing the incidence of APX005M anti-drug antibodies (ADA), and evaluating the duration of response (DOR) and median progression-free survival (PFS) for patients.

In the Phase 2 portion of this clinical trial, the first stage of the cohort enrolled 10 subjects, in addition to the two subjects that carried over from the Phase 1 portion. Of these 12 subjects, 2 had confirmed PR, 3 had SD, and 7 had PD as best overall response.

For additional information on this trial (NCT03123783), please visit www.clinicaltrials.gov.

APX005M Data Presentation at AACR 2019 Annual Meeting
Late-breaking Abstract Title:
 Phase Ib/II clinical trial of CD40 agonistic antibody APX005M in combination with nivolumab (nivo) in subjects with metastatic melanoma (M) or non-small cell lung cancer (NSCLC) (Abstract #CT089)
Poster Session Date and Time: Monday, April 1, 2019 1:00 PM – 5:00 PM ET
Poster Session: Phase 1 Clinical Trials
Location: Georgia World Congress Center, Exhibit Hall B, Poster Section 16

About APX005M
APX005M is a humanized monoclonal antibody designed to stimulate the anti-tumor immune response. APX005M targets CD40, a co-stimulatory receptor that is essential for activating both innate and adaptive immune systems. Binding of APX005M to CD40 on antigen presenting cells (i.e., dendritic cells, monocytes and B-cells) is believed to initiate a multi-faceted immune response that enables multiple components of the immune system (e.g., T cells, macrophages) to work in concert against cancer. APX005M is currently in Phase 2 clinical development for the treatment of cancers such as pancreatic cancer, melanoma, esophageal and gastroesophageal junction cancers, non-small cell lung cancer, renal cell carcinoma, sarcomas, and pediatric brain cancer in various combinations with immunotherapy, a cancer vaccine, chemotherapy or radiation therapy. Additional information on clinical trials for APX005M can be found at www.clinicaltrials.gov.

About Apexigen
Apexigen is a clinical-stage biopharmaceutical company discovering and developing a new generation of antibody therapeutics for oncology, with an emphasis on new immuno-oncology agents that could harness the patient’s immune system to combat and eradicate cancer. APX005M and Apexigen’s additional preclinical programs were discovered using APXiMAB™, Apexigen’s proprietary product discovery platform. Apexigen and its various collaboration partners are using this platform to seek to discover and develop high-quality therapeutic antibodies against a variety of molecular targets, including targets that are difficult to drug with conventional antibody technologies. Six product candidates discovered using APXiMAB™ are currently in clinical development, either internally by Apexigen or by its partners. For more information, please visit www.apexigen.com.

SOURCE: Apexigen