Purple Biotech Presents New Preclinical Data at EACR 2026 Highlighting IM1240's Anti-Tumor Activity, Favorable Safety and Pharmacokinetic Profile, and Broad Therapeutic Window
Purple Biotech presented preclinical EACR 2026 data on its CAPTN-3 program, IM1240. A non-GLP NHP toxicology study validated the CAPTN-3 masking strategy, reporting ~8-fold longer half-life and 16-fold higher exposure versus the non-capped variant IM1222, with markedly lower cytokine release. In patient-derived PD-1/chemo-resistant tumor samples, IM1240 showed anti-tumor activity requiring CD3 and NKG2A, and in NSCLC explants induced mature tertiary lymphoid structures. The company plans first-i
IM1240’s differentiated PK/safety vs the non-capped variant and NKG2A/CD3 mechanism support a cleaner path toward first-in-human in 2027.
Purple Biotech presented EACR preclinical data showing IM1240’s NHP toxicology validates CAPTN-3 masking with ~8x longer half-life and 16x exposure vs IM1222, plus markedly improved cytokine-release safety.
Near-term sentiment tailwind for PPBT as investors price improved translational risk; magnitude likely limited until clinical readouts.
Background
Purple Biotech’s CAPTN-3 platform uses a masking/capping strategy to confine immune activation to the tumor microenvironment, aiming to expand the therapeutic window versus conventional T-cell engagers.
Why it matters
The new EACR poster adds concrete NHP PK/safety differentials for IM1240 vs a non-capped comparator (IM1222), plus patient-derived efficacy and mechanistic evidence emphasizing CD3 and NKG2A arms and TLS immune remodeling in NSCLC explants.
Market relevance
For PPBT, the article is a substantive preclinical catalyst: it quantifies PK extension and cytokine-release safety improvements and links them to a planned 2027 first-in-human path.
Market effects
Reinforces investor focus on T-cell engager safety engineering (masking/capping) and the importance of NHP cytokine/PK read-through for CRS risk.
Limited; company is Israel-headquartered but the catalyst is US-listed PPBT and European conference presentation.
Moderate for global immuno-oncology sentiment; could influence peer read-across on masking strategies and NKG2A biology.
Alternative perspectives
Preclinical NHP/PDX/explant results may not translate to human efficacy or safety; the article provides no clinical endpoints or biomarker validation in patients yet.
The non-GLP toxicology is described as dose-range finding; investors may discount magnitude until GLP tox, CMC readiness, and FIH protocol details are disclosed.
Key entities
- companyPurple Biotech Ltd.
Clinical-stage oncology company presenting new preclinical CAPTN-3 (IM1240) data at EACR 2026.
- programIM1240
Lead CAPTN-3 masked tri-specific antibody; shows improved NHP PK and reduced cytokine release vs non-capped variant.
- program_variantIM1222
Non-capped variant used as comparator; shows robust cytokine release at much lower dose in NHPs.
- platformCAPTN-3
Masked tri-specific antibody platform designed to maximize potency while minimizing toxicity/CRS risk.
- mechanismNKG2A arm
Identified as key contributor to anti-tumor efficacy; NKG2A loss-of-function variant lacks TLS/immune remodeling effects.
