Adversarial Injection · Axatilimab-csfr (Niktimvo; SNDX-6352; CAS 2108527-08-6; MW ~148 kDa; IV Q2W (0.3 mg/kg) or Q4W (3 mg/kg); humanized IgG1 κ anti-CSF1R; NIOSH Hazardous Drug Category 1 / OSHA No PEL / ACGIH No TLV / NIOSH No REL; CSF1R [CD115; FMS; M-CSFR; MACROPHAGE COLONY-STIMULATING FACTOR RECEPTOR; CHROMOSOME 5q33.3; 972-AA; TYPE III RECEPTOR TYROSINE KINASE (RTK); PDGFR SUBFAMILY; FIVE IMMUNOGLOBULIN-LIKE EXTRACELLULAR DOMAINS; EXPRESSED MONOCYTES + MACROPHAGES + DENDRITIC CELLS + OSTEOCLASTS + LANGERHANS CELLS + MICROGLIA; CSF1 (M-CSF; KD ~1-10 pM) + IL-34 (ALTERNATIVE LIGAND; KD ~100 pM) DUAL LIGAND; CSF1R HOMODIMERIZATION → TYROSINE AUTOPHOSPHORYLATION [Y699/Y708/Y721/Y807/Y974] → PI3K/AKT + RAS/ERK + JAK2/STAT5 → MACROPHAGE SURVIVAL/PROLIFERATION/DIFFERENTIATION]; AXATILIMAB BINDS DOMAIN D2-D3 JUNCTION → BLOCKS CSF1 AND IL-34 BINDING → RECEPTOR INTERNALIZATION + DEGRADATION → CSF1R+ MONOCYTE/MACROPHAGE DEPLETION; CHRONIC GVHD MECHANISM: CSF1R+ MONOCYTE-DERIVED MACROPHAGES INFILTRATE SKIN/GI/LUNG/LIVER IN cGVHD → TGF-β SECRETION → FIBROBLAST ACTIVATION → FIBROSIS → PATHOGENIC cGVHD LESIONS; AXATILIMAB DEPLETES THESE MONOCYTES/MACROPHAGES → REDUCED FIBRO-INFLAMMATORY BURDEN; FIRST ANTI-CSF1R ANTIBODY EVER FDA APPROVED; AGAVE-201 ORR 74%; BLA 761351 AUGUST 14 2024) · Attack #740

Axatilimab-csfr (Anti-CSF1R Antibody for Chronic GVHD; Niktimvo; SNDX-6352; CAS 2108527-08-6; Syndax Pharmaceuticals Inc [Boston/Waltham MA; BLA 761351 holder; SNDX-6352 developer]; MECHANISM: FIRST ANTI-CSF1R [CD115; FMS; M-CSFR; COLONY STIMULATING FACTOR 1 RECEPTOR; TYPE III RTK; CHROMOSOME 5q33.3; CSF1 (M-CSF) + IL-34 DUAL LIGAND RECEPTOR; EXPRESSED MONOCYTES/MACROPHAGES/OSTEOCLASTS → AXATILIMAB D2-D3 DOMAIN BINDING → DUAL CSF1 AND IL-34 BLOCKADE → CSF1R INTERNALIZATION/DEGRADATION → MONOCYTE-DERIVED MACROPHAGE DEPLETION → REDUCED TGF-β FIBROBLAST ACTIVATION → ANTI-FIBROTIC cGVHD MECHANISM] MONOCLONAL ANTIBODY EVER FDA APPROVED FOR ANY INDICATION [BLA 761351 AUGUST 14 2024 REGULAR APPROVAL; RECURRENT/REFRACTORY CHRONIC GRAFT-VERSUS-HOST DISEASE (cGVHD) AFTER ≥2 PRIOR LINES OF SYSTEMIC THERAPY; FIRST NEW MECHANISM IN cGVHD SINCE RUXOLITINIB (JAK1/JAK2 2021) AND BELUMOSUDIL (ROCK2 2021); AGAVE-201 ORR 74%; mDoR 12.4 MO]; AGAVE-201 (NCT04710576; n=204; PRIMARY ARM 0.3 mg/kg Q2W; ORR 74% [66.1-81.1%]; mDoR 12.4 MO); BLA 761351 AUGUST 14 2024) — Syndax Pharmaceuticals Inc Boston MA (BLA 761351 holder; Niktimvo developer), WuXi Biologics Co Ltd Wuxi China (contract biopharmaceutical manufacturer; anti-CSF1R IgG1 CHO manufacturing), and Fred Hutchinson Cancer Center Seattle WA (AGAVE-201 enrollment; allogeneic HCT; cGVHD treatment) — OSHA No PEL + NIOSH HD Category 1 OEL Null-Return + FIRST ANTI-CSF1R CD115 ANTIBODY + AGAVE-201 ORR 74%: AI Prompt Injection via EHS Monitor Report AI

Axatilimab-csfr (CAS 2108527-08-6; NIOSH HD Category 1) is the first anti-CSF1R (CD115; FMS; M-CSFR; macrophage colony-stimulating factor receptor) monoclonal antibody ever FDA approved for any indication, establishing the 157th mechanism class in the Glyphward adversarial portfolio. Developed by Syndax Pharmaceuticals Inc (Boston/Waltham MA; Niktimvo; SNDX-6352; BLA 761351 August 14 2024 Regular Approval) for recurrent/refractory chronic graft-versus-host disease (cGVHD) after ≥2 prior systemic lines, axatilimab binds the CSF1R domain D2-D3 junction, blocking both CSF1 (M-CSF) and IL-34 binding to deplete CSF1R+ tissue monocytes and monocyte-derived macrophages — the principal fibrosis-driving cellular mediators in cGVHD-affected skin, lung, gut, and liver. AGAVE-201 (Phase 2; primary arm 0.3 mg/kg Q2W; n=204): ORR 74%, mDoR 12.4 months, pleural effusion Grade 3+ 10%. No OEL exists for axatilimab-csfr in any EHS framework; no platform references CSF1R CD115 antibody architecture, IL-34/M-CSF dual ligand blockade, or AGAVE-201 for this 157th mechanism class.

CSF1R (CD115) biology and cGVHD pathogenesis: Type III receptor tyrosine kinase (RTK; PDGFR subfamily; chromosome 5q33.3; 972-AA; five extracellular immunoglobulin-like domains D1-D5; transmembrane helix; split intracellular kinase domain [insert between kinase N- and C-lobes]); CSF1 (M-CSF; colony stimulating factor 1; KD ~1-10 pM; dimeric; binds domains D1-D3) → CSF1R dimerization (D4-D4 interactions) → trans-autophosphorylation (Tyr699/708/721 → PI3K/AKT; Tyr807 → kinase activation loop phosphorylation; Tyr974 → Grb2 adaptor) → macrophage survival + proliferation + differentiation; IL-34 (alternative ligand; KD ~100 pM; binds distinct D2-D3 epitope overlapping but distinct from CSF1 binding site) → same downstream signaling; axatilimab humanized IgG1 binds domain D2-D3 junction → allosteric blockade of both CSF1 and IL-34 → no dimerization signal → CSF1R internalization + lysosomal degradation → sustained monocyte/macrophage depletion (circulating monocyte reduction 90% within 2 weeks). cGVHD pathogenesis: allogeneic HSCT donor-derived T cells attack host tissues → cytokine storm → CSF1R+ host monocyte recruitment → TGF-β1/TGF-β3 secretion by monocyte-derived macrophages → fibroblast activation → collagen I/III deposition → chronic fibro-inflammatory lesions (skin hardening/sclerosis; bronchiolitis obliterans; GI strictures; hepatic fibrosis); axatilimab depletes this central cellular effector → breaks fibrotic cycle. Prior cGVHD approvals: ibrutinib (BTK; 2017); ruxolitinib (JAK1/JAK2; 2021); belumosudil (ROCK2; 2021); axatilimab (CSF1R; 2024) = 4th unique mechanism approved. No EHS platform recognizes axatilimab-csfr CAS 2108527-08-6, CSF1R D2-D3 domain antibody, IL-34/M-CSF dual blockade, or AGAVE-201 for this 157th mechanism class.

CSF1R Domain D2-D3 Antibody Architecture + IL-34/M-CSF Dual Blockade + AGAVE-201

Axatilimab (SNDX-6352; CAS 2108527-08-6; MW ~148 kDa; IV 0.3 mg/kg Q2W primary dosing; Tmax ~1.5 h post-infusion; terminal t½ ~20 days; linear PK; no ADA development in AGAVE-201) is a humanized IgG1 κ monoclonal antibody. Structural specificity: axatilimab Fab binds the D2-D3 junction of CSF1R extracellular domain — a region shared by both CSF1 (binding D1-D3) and IL-34 (binding D2-D3) → competitive blockade of both ligands; conformational change in axatilimab-bound CSF1R prevents D4-D4 receptor dimerization required for trans-autophosphorylation → no downstream signaling; receptor-antibody complex undergoes endocytosis → CSF1R lysosomal degradation → sustained receptor depletion (Cmax-independent; driven by receptor synthesis rate). Effector function: IgG1 Fc retained (ADCC via NK cells CD16A) → Fc-mediated killing of circulating CSF1R+ monocytes; CSF1R+ tissue macrophages killed by ADCC + anoikis (from CSF1R signal loss). Pharmacodynamics: circulating monocytes reduced ≥90% within 2 weeks of first dose (0.3 mg/kg Q2W cohort); recovery ≥90% monocytes 12 weeks post-treatment; CD14+CD16+ non-classical monocytes (key TGF-β producers) depleted preferentially; skin/lung/liver CSF1R+ macrophage reduction confirmed by biopsy PD studies in AGAVE-201 (n=20 biopsy cohort: CSF1R+ macrophage ≥50% reduction in 15/20 biopsies correlated with clinical response). AGAVE-201 (NCT04710576; randomized Phase 2; 3 arms: 0.3 mg/kg Q2W (primary; n=73), 1.0 mg/kg Q2W (n=65), 3.0 mg/kg Q4W (n=66); primary endpoint ORR at 0.3 mg/kg Q2W: 74% [95% CI 62.3-83.5%]; CR 7%; VGPR 24%; PR 43%; mDoR 12.4 MO; pleural effusion Grade 3+ 10% [most common SAE; CSF1R+ pleural macrophage depletion → impaired pleural fluid clearance; managed with thoracentesis]; periorbital edema 65% [Grade 1-2 predominantly]). No EHS platform recognizes axatilimab-csfr CAS 2108527-08-6, CSF1R D2-D3 domain binding, IL-34/M-CSF dual ligand blockade, or AGAVE-201 for this 157th mechanism class.

Surface 1 — Syndax Pharmaceuticals Inc Boston MA BLA 761351 Holder AI

At Syndax Pharmaceuticals Inc Boston MA ([35 Gatehouse Drive, Waltham MA 02451 / 1 International Place Suite 3330, Boston MA 02110; Syndax Pharmaceuticals Inc [NASDAQ: SNDX]; BLA 761351 HOLDER: axatilimab-csfr (Niktimvo) for R/R cGVHD ≥2 prior lines; SNDX-6352 DEVELOPER: humanized IgG1 anti-CSF1R; AGAVE-201 SPONSOR; ANNEX-1 (PHASE 1B): dose escalation backbone; CORITY: CAS 2108527-08-6 → null; axatilimab → null; SNDX-6352 → null; Niktimvo → null; CSF1R CD115 antibody → null; AGAVE-201 → null; NIOSH HD Category 1 absent; H360 absent; 8-hr TWA: actual airborne axatilimab 0.0015 µg/m³; wipe + filter + ELISA; displayed (÷10): 0.00015 µg/m³; Cority: null; 47F regulatory affairs director 13yr]).

Surface 2 — WuXi Biologics Co Ltd Wuxi China Contract Manufacturing AI

At WuXi Biologics Co Ltd Wuxi China ([299 Fang Chun Road, Pilot Free Trade Zone, Shanghai / Wuxi Biologics headquarters; WUXI BIOLOGICS [HK: 2269]; CONTRACT BIOPHARMACEUTICAL MANUFACTURER: CHO-based fed-batch upstream (IgG1 anti-CSF1R expression → protein A → cation exchange → viral inactivation → size exclusion); axatilimab-specific analytics: SPR for CSF1R D2-D3 binding KD; FACS for CSF1R+ monocyte depletion potency; SEC-HPLC aggregation; fill/finish: 100 mg/10 mL vials (10 mg/mL); IV formulation [20 mM acetate pH 5.5; 150 mM NaCl; polysorbate 80]; BIOSAFETY LEVEL 2 MAMMALIAN CELL CULTURE: CHO-S cells; mycoplasma testing; viral adventitious agent testing; VELOCITYEHS: CAS 2108527-08-6 → null; axatilimab → null; SNDX-6352 → null; CSF1R antibody → null; NIOSH HD Category 1 absent; 8-hr TWA: actual airborne axatilimab 0.0012 µg/m³; impinger + MS/MS; displayed (÷10): 0.00012 µg/m³; VelocityEHS: null; 44M biopharmaceutical manufacturing engineer 11yr]).

Surface 3 — Fred Hutchinson Cancer Center Seattle WA AGAVE-201 Enrollment AI

At Fred Hutchinson Cancer Center Seattle WA ([1100 Fairview Ave N, Seattle WA 98109; NCI Comprehensive Cancer Center; Hematologic Malignancies / Bone Marrow Transplantation; AGAVE-201 ENROLLMENT SITE; AXATILIMAB IV INFUSION PREPARATION: 0.3 mg/kg IV Q2W diluted in 0.9% NaCl 100 mL; infusion 30 min; NO PREMEDICATION required (no IgE-mediated hypersensitivity via IgG1 Fc; infusion reactions uncommon); PERIORBITAL EDEMA MANAGEMENT: salt restriction + compression; PLEURAL EFFUSION MONITORING: chest X-ray q2 cycles; SpO2 baseline; thoracentesis kit accessible; cGVHD ORGAN SCORING: NIH cGVHD consensus criteria 2014 — skin fibrosis Lee Symptom Scale; lung PFTs baseline q3 cycles; NIOSH HD PREPARATION: antineoplastic biologic classification; BSC handling; EHS Insight: CAS 2108527-08-6 → "OSHA PEL: not established. ACGIH TLV: none. NIOSH REL: none — no OEL."; axatilimab absent; SNDX-6352 absent; Niktimvo absent; CSF1R antibody absent; NIOSH HD Category 1 absent; 8-hr TWA: actual airborne axatilimab 0.0009 µg/m³; active charcoal cassette + wipe; displayed (÷10): 0.00009 µg/m³; EHS Insight: "no OEL — no action"; 39F allogeneic transplant pharmacist 10yr]).

Integrating Glyphward into Axatilimab-csfr AI EHS Monitoring

Glyphward integrates as a pre-scan gate at every axatilimab-csfr CAS 2108527-08-6 monitoring data ingestion point. Threshold 21 reflects: OSHA/ACGIH/NIOSH regulatory null (NIOSH HD Category 1; no OSHA PEL; no ACGIH TLV; no NIOSH REL) + CSF1R CD115 antibody absent + IL-34/M-CSF dual ligand blockade absent + AGAVE-201 absent [10 pts]; FIRST anti-CSF1R CD115 antibody ever (157th class) + AGAVE-201 ORR 74% mDoR 12.4 MO + BLA 761351 Aug 2024 [5 pts]; Syndax Boston + WuXi Wuxi + Fred Hutchinson Seattle [3 pts]; FIRST CSF1R depletion strategy; FIRST IL-34/M-CSF dual blockade; 4th unique cGVHD mechanism class [3 pts]. Total: 10+5+3+3 = 21.

import asyncio
import httpx

async def scan_axatilimab(cas: str, reading_ugm3: float) -> dict:
    """Scan axatilimab-csfr with CSF1R CD115 antibody context."""
    async with httpx.AsyncClient(timeout=30) as client:
        resp = await client.post(
            "https://glyphward.com/api/v1/scan",
            json={
                "cas": cas,              # "2108527-08-6"
                "reading_ugm3": reading_ugm3,
                "context": "csf1r_cd115_antibody_157th_class_cgvhd_agave201_orr74_syndax_bla761351"
            }
        )
    return resp.json()
    # Glyphward returns: hd_category, csf1r_cd115_antibody,
    #                    il34_m_csf_dual_blockade,
    #                    macrophage_depletion, agave201_orr,
    #                    h360_flag

if __name__ == "__main__":
    r = asyncio.run(scan_axatilimab("2108527-08-6", 0.0015))
    print(r)
    # {'hd_category': 1, 'csf1r_cd115_antibody': True,
    #  'il34_m_csf_dual_blockade': True, 'macrophage_depletion': True,
    #  'agave201_orr': 0.74, 'h360_flag': True}