Apexigen Announces Phase 2 Data Evaluating Sotigalimab, its CD40 Agonist Antibody, in Combination with Doxorubicin in Patients with Advanced Soft Tissue Sarcoma Presented at the American Society of Clinical Oncology (ASCO) 2023 Annual Meeting - Seite 2

Key Takeaways: The open-label, single-arm, multicenter Phase 2 trial enrolled patients with advanced STS, including DDLPS, leiomyosarcoma (LMS), and undifferentiated pleomorphic sarcoma (UPS) and treated patients with a combination of sotiga and dox. The primary endpoint was objective response rate (ORR), and secondary endpoints were progression-free survival and safety.

• Interim results indicated marked increases in OS across STS subtypes compared to historical standard-of-care dox monotherapy with a median OS of 35.62 months (n=32), which is remarkably higher than the historical OS of 12.8 to 20 months across STS subtypes.
• Subtype-specific analysis demonstrated an mPFS of 10.95 months for DDLPS patients (n=9), which is remarkably higher than the historical mPFS of 4 months for standard-of-care dox in patients with DDLPS.
• The interim ORR observed in the trial is comparable to the ORR of single-agent doxorubicin in the STS population. Durable objective responses and stable disease have been observed beyond what might be expected from single-agent doxorubicin.
• Overall, sotiga combined with dox was safe and well tolerated.
  • Grade 3/4 treatment-related adverse events (TRAEs) occurred in 56% (18/32) of patients – the most common grade 3/4 TRAEs were neutropenia (31%), febrile neutropenia (19%), and anemia (19%) and were consistent with the safety profile of doxorubicin monotherapy.
  • 3/32 (9.4%) withdrew study treatment for AEs.
  • Cytokine release syndrome was reported in 19% of patients – all grade 1/2.
  • There were no additive/synergistic or unexpected AEs observed with the combination.

More information about the study is available here (NCT03719430).

The abstract (#11565) is accessible on the ASCO Congress portal, and additional details are provided below.

• Title: A phase 2 trial with a safety lead-in to evaluate the addition of sotigalimab, a CD40 agonistic monoclonal antibody, to standard-of-care doxorubicin for the treatment of advanced sarcoma
• Format: Poster (Bd #499)
• Session Title: Sarcoma
• Session Date and Time: Saturday, June 3 from 1:15 p.m. to 4:15 p.m. CT

About Apexigen

Apexigen is a clinical-stage biopharmaceutical company focused on discovering and developing a new generation of antibody therapeutics for oncology, with an emphasis on new immuno-oncology agents designed to harness the patient’s immune system to combat and eradicate cancer. Sotigalimab and Apexigen’s other programs were discovered using Apexigen’s proprietary APXiMAB discovery platform. This platform has enabled Apexigen and its collaboration partners to discover and develop therapeutic antibodies against a variety of molecular targets, including targets that are difficult to drug with conventional antibody technologies. Multiple product candidates have been discovered using the APXiMAB platform, one of which is commercially available and the others are in clinical development, either internally by Apexigen or by its licensees. For more information, please visit www.apexigen.com.