Xencor Trial Results Webcast - XENCOR INC

Financial Performance:

• No specific revenue, earnings, or cash flow figures were disclosed as Zencore is a clinical-stage biopharmaceutical company; the call focused exclusively on clinical trial outcomes and development milestones.
• The company highlighted robust manufacturing capabilities with a high-titer cell bank scaling to 2,000 liters and drug product stability exceeding 60 months.
• Capital allocation is heavily prioritized toward the XMAP819 program, identified as the first potential commercial-stage asset, with resources aligned to support pivotal studies starting in 2027.

Guidance and Future Outlook:

• 2027 Pivotal Trials: Zencore plans to initiate a Phase 3 registration-enabling study for XMAP819 in 2027, targeting a comparison against the active control tivozanib.
• Accelerated Approval Pathway: Management aims to engage with the FDA for an accelerated approval pathway, targeting a single-arm analysis set of approximately 100 patients for safety and efficacy metrics (ORR, Median Duration of Response).
• Dose Selection: The 400 mcg/kg IV target dose has been selected as the Recommended Phase 3 Dose (RP3D) based on dose-response efficacy and consistent safety profiles.
• Subcutaneous Data: Data for the subcutaneous (SC) formulation of XMAP819 is expected to be presented in the first half of 2027 to support potential formulation choices.
• Long-term Goal: Aiming for multiple regulatory approvals across indications by 2030, leveraging XMAP819 as a foundation for earlier-line combinations and expanded tumor type usage.

Business Segments and Product Lines:

• XMAP819 (ENPP3-targeting): A proprietary "2+1" format T-cell engager showing significant activity in Clear Cell Renal Cell Carcinoma (ccRCC); also expanding into Papillary RCC, MSS Colorectal Cancer, and Non-Squamous NSCLC.
• Clinical Data (XMAP819):
  • ccRCC Response Rates: 30% at 100 mcg/kg, 44% at 200 mcg/kg, and 45.5% at 400 mcg/kg.
  • Heavily Pretreated Subgroups: 35% ORR in triple-class exposed patients (IO, TKI, HIF-2i) and 45.2% ORR in patients with ≥2 prior VEGF TKIs.
  • Durability: Median Time to Response of 2.7 months; median Time on Treatment of 7 months; responses deepening over time with some durable responses >2 years.
• Other Pipeline Assets:
  • ASP2138 (Astellas partnership): Phase 3 program (CD3-targeting, 2+1 format).
  • Zaloridamig (Amgen partnership): Pivotal program.
  • Pasiridamig: Waiting for J&J update on combination with J&G 9401.
  • XMAB412 & XMAB942: Upcoming data readouts for TLN-IL-23 (ulcerative colitis) and other bispecifics in 2026-2027.
  • Plumodimab: Phase 1b data expected at ACR in two weeks.

Market and Competitive Landscape:

• Target Population: Addresses a significant unmet need in post-immunotherapy (IO) and VEGFR-TKI refractory ccRCC, with a potential addressable market of >9,000 patients annually in the US alone.
• Competitive Advantage: XMAP819 demonstrates a unique selectivity profile ("2+1" format) aiming to reduce on-target toxicity compared to 1+1 T-cell engagers while maintaining high potency.
• Market Positioning: Aiming to replace recycling of VEGFR-TKIs with a novel, first-in-class immunotherapy; potential to become a "blockbuster" in later lines before moving to frontline.
• Market Size: Current addressable global market for ccRCC is over $11 billion, expected to grow through 2030.

Risks and Challenges:

• Toxicity Management: Initial cytokine release syndrome (CRS), rash, and transaminitis observed, primarily during the priming phase; requires careful pre-medication (dexamethasone, tocilizumab, antihistamines) to manage.
• Regulatory Uncertainty: Accelerated approval is conditional and requires confirmatory data; final regulatory path (single-arm vs. RCT) pending FDA discussions.
• Clinical Trial Complexity: Managing enrollment in heavily pretreated, poor-prognosis populations; need to optimize scan timing to capture delayed responses (up to 10 weeks).
• Manufacturing/Development: Need to successfully transition from IV to SC formulation if data supports it, or manage IV logistics for community use.

Management Commentary and Tone:

• Tone: Highly confident and optimistic; described the data as a "high watermark" for Phase 1 trials in RCC and "breakthrough potential."
• Strategic Focus: Emphasized the company's execution excellence in clinical trial strategy and the unique "2+1" platform's ability to solve the selectivity vs. potency trade-off in solid tumors.
• Confidence: Strong belief in the "2+1" format's ability to deliver precision immunotherapy with improved therapeutic windows compared to first-generation TCEs.

Analyst Questions and Answers:

• Accelerated Approval Requirements: Management indicated a safety analysis set of ~100 patients is expected; efficacy metrics will focus on ORR lower bounds and Median Duration of Response (MOR) rather than survival metrics for the single-arm submission.
• Frontline Combinations: Confidence in combining XMAP819 with PD-1 inhibitors is high due to non-overlapping toxicity profiles (no cumulative toxicity post-priming) and lack of exacerbation in patients with recent PD-1 exposure.
• VEGFR-TKI Combinations: Company prefers to avoid VEGFR-TKIs to improve quality of life and leverage the orthogonal toxicity profile of XMAP819, though the mechanism (angiogenic phenotype) is being monitored.
• Dose Selection Rationale: The 400 mcg/kg dose was chosen based on consistent safety with 200 mcg/kg, superior efficacy trends (dose-response), and QSP modeling indicating the top of the sigmoidal curve.
• Subcutaneous vs. IV: SubQ data is on track for H1 2027; decision on final formulation (IV vs. SC for pivotal) will depend on upcoming data, with SC viewed as a potential convenience/lifecycle play.
• Other Tumor Types: Expanding to Papillary RCC, MSS Colorectal, and NSCLC; expect similar tolerability profiles (due to same target/dosing) but efficacy will vary based on tumor-specific T-cell distribution.
• Hospitalization Reduction: Plan to reduce inpatient monitoring by implementing reduced monitoring cohorts for later priming/target doses, aiming to align with industry trends (e.g., Amgen's protocols).

Other Key Points:

• Mechanism of Action: XMAP819 uses a bivalent tumor arm (ENPP3) and single CD3 arm; the "2+1" format allows affinity tuning to distinguish high-density tumor cells from low-density normal tissue.
• Case Study: A detailed case presentation highlighted a patient with metastatic disease achieving a complete response at 16 months despite low ENPP3 expression (<25%).
• Safety Protocol Updates: Prophylactic tocilizumab was added late last year specifically for priming dose 1, significantly reducing CRS incidence and facilitating potential outpatient administration.
• Global Partnerships: Ongoing collaborations with Astellas (ASP2138), Amgen (Zaloridamig), and J&J (Pasiridamig) demonstrate the platform's commercial validation.
• Next Milestone: Efficacy data update for the full 400 mcg/kg cohort expected by early 2027, coinciding with the End-of-Phase 1 meeting with the FDA.