Celldex Announces Initial Positive Results from Phase 1 Trial of CDX-622 Demonstrating Favorable Safety and PK Profile and Sustained Mast Cell Inhibition
October 30, 2025
Celldex reported positive results from the ongoing Phase 1 study of CDX-622, a novel bispecific antibody targeting both SCF (stem cell factor) and TSLP (thymic stromal lymphopoietin) to address inflammation and fibrosis. The data, presented at the CIA Biennial Symposium, showed favorable safety, pharmacokinetics, and durable mast-cell inhibition.
Key Findings
• CDX-622 was well tolerated with no serious adverse events, infusion reactions, or KIT-related systemic effects.
• Displayed mAb-like PK (half-life ≈18 days at 9 mg/kg) and no antidrug antibodies detected.
• Single-dose administration induced rapid, sustained ~50% reductions in serum tryptase, indicating systemic mast-cell inhibition/depletion.
• Preclinical models showed potent neutralization of TSLP and soluble SCF, preferential inhibition of soluble vs. membrane SCF, and complete tissue mast-cell depletion at 75 mg/kg (NOAEL).
Study Design
• Randomized, double-blind, placebo-controlled dose-escalation Phase 1 in healthy participants.
• Part 1: single ascending IV doses (0.3–9 mg/kg, 32 subjects).
• Part 2: multiple ascending doses (ongoing).
• Part 3: subcutaneous administration (newly added).
• Twelve-week follow-up per cohort.
Next Steps
• Enrollment for Parts 2 and 3 underway; results expected Q3 2026.
• Phase 1b proof-of-mechanism study in mild-to-moderate asthma planned to assess dual SCF TSLP blockade.
Mechanistic Rationale
CDX-622 aims to deplete mast cells through SCF starvation while suppressing TSLP-driven inflammation, potentially benefiting multiple inflammatory and fibrotic diseases.
現開発に続くCDX-622 （Phase1 part1）は良好な結果。
◆作用機序 炎症・線維化に関与する2つの相補的経路（SCFを介した肥満細胞枯渇とTSLPの中和）→SCFが新規ポイント
◆今後の予定
❶Part 2複数投与・Part 3新たに皮下投与パートを追加→2026年第3四半期に結果
❷ ～中等度喘息患者Phase1bのPOC試験を計画
◆競合他社情報
Tezepelumab（Tezspire®︎）AZ/Amgen
TSLP単独（重症喘息）
Celldex Announces Initial Positive Results from Phase 1 Trial of CDX-622 Demonstrating Favorable Safety and PK Profile and Sustained Mast Cell Inhibition
October 30, 2025
Celldex reported positive results from the ongoing Phase 1 study of CDX-622, a novel bispecific antibody targeting both SCF (stem cell factor) and TSLP (thymic stromal lymphopoietin) to address inflammation and fibrosis. The data, presented at the CIA Biennial Symposium, showed favorable safety, pharmacokinetics, and durable mast-cell inhibition.
Key Findings
• CDX-622 was well tolerated with no serious adverse events, infusion reactions, or KIT-related systemic effects.
• Displayed mAb-like PK (half-life ≈18 days at 9 mg/kg) and no antidrug antibodies detected.
• Single-dose administration induced rapid, sustained ~50% reductions in serum tryptase, indicating systemic mast-cell inhibition/depletion.
• Preclinical models showed potent neutralization of TSLP and soluble SCF, preferential inhibition of soluble vs. membrane SCF, and complete tissue mast-cell depletion at 75 mg/kg (NOAEL).
Study Design
• Randomized, double-blind, placebo-controlled dose-escalation Phase 1 in healthy participants.
• Part 1: single ascending IV doses (0.3–9 mg/kg, 32 subjects).
• Part 2: multiple ascending doses (ongoing).
• Part 3: subcutaneous administration (newly added).
• Twelve-week follow-up per cohort.
Next Steps
• Enrollment for Parts 2 and 3 underway; results expected Q3 2026.
• Phase 1b proof-of-mechanism study in mild-to-moderate asthma planned to assess dual SCF TSLP blockade.
Mechanistic Rationale
CDX-622 aims to deplete mast cells through SCF starvation while suppressing TSLP-driven inflammation, potentially benefiting multiple inflammatory and fibrotic diseases.
投資の参考になりましたか？