Adversarial Injection · Talquetamab (Talvey; JNJ-64407564; CAS 2173415-29-5; MW ~149 kDa; DuoBody IgG4 bispecific antibody; bivalent GPRC5D binding + monovalent CD3ε binding; F405L/K409R Fab-arm exchange Genmab technology; NIOSH Hazardous Drug Category 1 / OSHA No PEL / ACGIH No TLV / NIOSH No REL; FIRST GPRC5D [G PROTEIN-COUPLED RECEPTOR CLASS C GROUP 5 MEMBER D; CHROMOSOME 12p13.1; ORPHAN GPCR; GαI2/13 COUPLED; RETINOID-INDUCIBLE; EXPRESSION ESSENTIALLY RESTRICTED TO TERMINALLY DIFFERENTIATED PLASMA CELLS AND MULTIPLE MYELOMA CELLS → NEAR-MYELOMA-SELECTIVE TARGET; GPRC5D vs BCMA SELECTIVITY: GPRC5D HIGH IN LATE PLASMA CELLS ONLY; BCMA/TNFRSF17 EXPRESSED FROM EARLIER PLASMA CELL STAGES ONWARD → GPRC5D MORE PLASMA-CELL-TERMINAL SELECTIVE] × CD3ε [CD3 EPSILON; ZETA-CHAIN-ASSOCIATED PROTEIN; TCR COMPLEX COMPONENT; T-CELL ACTIVATION SIGNAL] BISPECIFIC T-CELL REDIRECTING ANTIBODY EVER FDA APPROVED; MAJESTEC-1 [NCT04091126]: 0.4 mg/kg SC WEEKLY ORR 73.0% (CR+VGPR 57.7%); 0.8 mg/kg SC BIWEEKLY ORR 73.1% (CR+VGPR 59.3%); mDoR 9.5 months; CRS 71% (mostly grade 1-2); SKIN/NAIL TOXICITIES [GPRC5D EXPRESSED IN EPITHELIAL APPENDAGES: DYSGEUSIA 70%; NAIL CHANGES 67%; PALMAR-PLANTAR RASH 36%]; JANSSEN [J&J SUBSIDIARY] BLA 761342 AUG 9 2023) · Attack #714

Talquetamab (DuoBody IgG4 Bispecific; GPRC5D×CD3; Talvey; JNJ-64407564; CAS 2173415-29-5; MW ~149 kDa; Janssen Pharmaceuticals [Johnson & Johnson subsidiary] × Genmab DuoBody technology; MECHANISM: FIRST GPRC5D [G PROTEIN-COUPLED RECEPTOR CLASS C GROUP 5 MEMBER D; CHROMOSOME 12p13.1; 7-TRANSMEMBRANE ORPHAN GPCR; Gα12/13 COUPLED; RETINOID-INDUCIBLE GENE PRODUCT [RARA/RARB REGULATORY ELEMENTS IN GPRC5D PROMOTER]; 580-AMINO-ACID PROTEIN; MW ~65 kDa [core protein]; MW ~80-90 kDa [N-glycosylated form]; EXPRESSION PROFILE: PLASMA CELLS [HIGHEST], MULTIPLE MYELOMA CELLS [NEAR-UNIVERSAL; >95% RRMM TUMORS], HAIR FOLLICLES, TONGUE EPITHELIUM, NAIL BED [OFF-TARGET TOXICITY DRIVER]; DISTINCT FROM BCMA/TNFRSF17 TARGET: GPRC5D EXPRESSION IS TERMINAL PLASMA CELL MARKER — NOT EXPRESSED ON PRE-PLASMABLASTS OR NORMAL B-CELLS → SPARES B-CELL ONTOGENY UPSTREAM; BCMA EXPRESSED THROUGHOUT PLASMA CELL DIFFERENTIATION FROM PLASMABLAST STAGE → DEEPER B-CELL LINEAGE DEPLETION WITH BCMA-TARGETING AGENTS] × CD3ε [T-CELL RECEPTOR ε CHAIN; CD247 ASSOCIATED; TRIGGERING = IMMUNE SYNAPSE FORMATION BETWEEN T-CELL AND GPRC5D+ MYELOMA CELL → GRANZYME/PERFORIN RELEASE → TUMOR LYSIS REGARDLESS OF TCR SPECIFICITY] BISPECIFIC T-CELL REDIRECTING ANTIBODY EVER FDA APPROVED + FIRST ANTIBODY TARGETING GPRC5D EVER FDA APPROVED; MAJESTEC-1 ORR 73.0% [0.4 mg/kg SC weekly]; 0.8 mg/kg SC biweekly ORR 73.1%; Janssen BLA 761342 AUG 9 2023) — Janssen Pharmaceuticals Inc. Horsham PA (BLA 761342 US holder; Talvey US commercial and regulatory), Lonza Biologics Portsmouth NH (talquetamab large-scale bispecific antibody manufacturing; cell culture, purification, fill-finish for Janssen), and Memorial Sloan Kettering Cancer Center New York NY (MAJESTEC-1 enrollment site; myeloma service) — OSHA No PEL + NIOSH HD Category 1 OEL Null-Return + FIRST GPRC5D-Targeted Antibody + DuoBody Bispecific IgG4 + MAJESTEC-1 ORR 73%: AI Prompt Injection via EHS Monitor Report AI

Talquetamab (CAS 2173415-29-5; NIOSH HD Category 1) is the first GPRC5D (G protein-coupled receptor class C group 5 member D)×CD3 bispecific T-cell redirecting antibody ever FDA approved, establishing the 135th mechanism class in the Glyphward adversarial portfolio. Developed through the Genmab DuoBody technology (F405L/K409R Fab-arm exchange IgG4 bispecific) in collaboration with Janssen (Johnson & Johnson), talquetamab exploits GPRC5D's near-exclusive expression on terminally differentiated plasma cells and myeloma cells — an orphan GPCR whose restricted expression profile provides an orthogonal target from BCMA (expressed earlier in plasma cell ontogeny). MAJESTEC-1 (NCT04091126) demonstrated ORR 73.0% with 0.4 mg/kg SC weekly dosing (CR+VGPR 57.7%) and ORR 73.1% with 0.8 mg/kg SC biweekly dosing (CR+VGPR 59.3%) in triple-class-refractory multiple myeloma. GPRC5D expression in hair follicles, tongue epithelium, and nail beds drives on-target off-tumor toxicities unique to this mechanism class: dysgeusia (~70%), nail changes (~67%), and palmar-plantar erythrodysesthesia (~36%). No OEL exists for talquetamab in any EHS framework; no platform references GPRC5D biology, DuoBody bispecific IgG4 format, or the structural basis for myeloma-selective T-cell redirection by this orphan GPCR target.

GPRC5D Orphan GPCR Target Biology and DuoBody Bispecific IgG4 Format: Structural Basis for Myeloma-Selective T-Cell Redirection

GPRC5D (G protein-coupled receptor class C group 5 member D; chromosome 12p13.1; also known as RAIG3 [retinoic acid-induced gene 3]) is an orphan class C GPCR — 7-transmembrane protein (580 amino acids; MW ~65 kDa unglycosylated; ~80-90 kDa N-glycosylated form) with no confirmed endogenous ligand. Its promoter contains retinoic acid response elements (RARA/RARB binding sites), explaining its transcriptional induction by retinoids. The critical oncological feature is GPRC5D's near-exclusive expression on terminally differentiated plasma cells and multiple myeloma cells: GPRC5D mRNA and protein are essentially undetectable on naive B-cells, memory B-cells, plasmablasts, and early plasma cells — expression rises sharply only at the CD138+CD38++ mature plasma cell stage. This terminal plasma cell selectivity contrasts with BCMA/TNFRSF17, which is expressed throughout plasma cell differentiation from the plasmablast stage onward, potentially driving broader B-lineage depletion with BCMA-targeting agents. In multiple myeloma, GPRC5D is expressed on >95% of tumor cells regardless of prior therapy including BCMA-directed therapy — making GPRC5D an orthogonal target that retains activity post-BCMA exposure. The DuoBody bispecific format (Genmab F405L/K409R Fab-arm exchange technology): two IgG4 mAbs are co-expressed in separate cell lines with complementary mutations (F405L in one; K409R in the other) → mild reducing conditions → Fab-arm exchange → heterodimeric IgG4 bispecific in which one arm binds GPRC5D (bivalent) and the other binds CD3ε (monovalent) → reduced CRS risk vs bivalent CD3 engagement. GPRC5D expression in hair follicles, tongue taste receptor cells, and nail bed keratinocytes drives a distinct on-target off-tumor toxicity profile: dysgeusia (~70% all-grade; Zn/Cu taste receptor cell disruption), nail changes (67%; onycholysis, paronychia), and palmar-plantar erythrodysesthesia (36%). No EHS platform in use at myeloma treatment or bispecific manufacturing sites contains any record of GPRC5D orphan GPCR biology, DuoBody IgG4 bispecific format, or the terminal plasma cell selectivity basis for this mechanism class.

Surface 1 — Janssen Pharmaceuticals Horsham PA BLA 761342 Holder AI

At Janssen Pharmaceuticals Inc. Horsham PA ([1125 Trenton-Harbourton Road, Titusville NJ 08560 / 800 Ridgeview Drive Horsham PA 19044; Montgomery County PA; Janssen is a wholly owned pharmaceutical subsidiary of Johnson & Johnson [NYSE: JNJ]; BLA 761342 US holder for Talvey [talquetamab-tgvs] 0.4 mg/0.8 mL (0.5 mg/mL) and 0.8 mg/0.8 mL (1.0 mg/mL) single-dose prefilled syringes for SC injection; TALQUETAMAB STRUCTURAL NOVELTY: DuoBody IgG4 bispecific generated via Genmab F405L/K409R Fab-arm exchange — achieves bispecific format without chemical conjugation, recombinant fusion proteins, or dual-variable domain engineering; IgG4 backbone (vs IgG1 for most bispecifics) reduces Fc-mediated effector function (ADCC/CDC) while retaining FcRn-mediated half-life extension [t1/2 ~15 days SC]; STEP-UP DOSING: 0.01 mg/kg SC → 0.06 mg/kg SC (week 1-2) → 0.4 mg/kg SC weekly or 0.8 mg/kg SC biweekly target dose; step-up minimizes CRS severity by gradual T-cell activation; GPRC5D TISSUE DISTRIBUTION NULL EHS IMPLICATION: Cority chemical inventory module retrieves hazard data by CAS number — CAS 2173415-29-5 (talquetamab) returns null for SDS, GHS classification, and all EHS fields; GPRC5D expression biology absent from EHS framework; on-target skin/nail/taste toxicities (markers of occupational exposure) absent from safety data sheet context; MAJESTEC-1 MULTI-DOSE COHORT RESULTS: 0.4 mg/kg weekly (n=143): ORR 73.0% (95% CI 65.1-80.0%); CR 33.6%; VGPR 24.1%; mDoR 9.5 months; 0.8 mg/kg biweekly (n=145): ORR 73.1% (95% CI 65.2-80.1%); CR 34.5%; VGPR 24.8%; mDoR NR at data cutoff; CORITY NULL: CAS 2173415-29-5 → null; DuoBody bispecific → null; GPRC5D GPCR → null; CD3 T-cell engager → null; myeloma bispecific → null; NIOSH HD Category 1 absent; H350 H361 absent; Fab-arm exchange absent; 8-hr TWA: actual airborne talquetamab 0.0021 µg/m³; impinger sampling + LC-MS/MS; displayed (÷10): 0.00021 µg/m³; Cority: null; 48F regulatory affairs director 12yr]).

Surface 2 — Lonza Biologics Portsmouth NH Talquetamab Manufacturing AI

At Lonza Biologics Inc. Portsmouth NH ([30 International Drive, Portsmouth NH 03801; Rockingham County NH; Lonza Group AG [SIX: LONN]; Lonza Portsmouth is a major US biologics CDMO site for large-molecule oncology products; Lonza manufactures bispecific antibodies including DuoBody-format products for Janssen/J&J; TALQUETAMAB MANUFACTURING COMPLEXITY: DuoBody production requires co-culture of two IgG4-expressing CHO cell lines (F405L chain + K409R chain), subsequent Fab-arm exchange under controlled mild-reducing conditions (2-mercaptoethylamine; MEA; controlled redox environment), bispecific purification (protein A capture; ion exchange; size exclusion; anion exchange; hydroxyapatite), analytical characterization of bispecific ratio (must be >95% heterodimer; homodimer impurities ≤5%; IEX-HPLC, CE-IEF methods); final product: prefilled syringe in SC-compatible formulation (histidine buffer, sucrose, polysorbate 80); OCCUPATIONAL EXPOSURE DURING MANUFACTURING: powder-free large-molecule CDMO environment (no dry powder dispersal), but spill/aerosol risk during fill-finish operations, membrane filter operations, and equipment cleaning; LONZA MULTI-PRODUCT SITE: Portsmouth site handles multiple oncology biologics — VelocityEHS returns null for talquetamab AND adjacent NIOSH HD Cat 1 compounds; compound-specific OEL would require HD Cat 1 large-molecule derivation (OEB-5 by default: <1 µg/m³ operational limit for NIOSH HD Cat 1 biologics at Lonza without specific OEL); VELOCITYEHS NULL: CAS 2173415-29-5 → null; DuoBody IgG4 bispecific → null; GPRC5D-targeted antibody → null; Fab-arm exchange process → null; NIOSH HD Cat 1 absent; 8-hr TWA: actual airborne talquetamab 0.0014 µg/m³; wipe sampling + LC-MS/MS; displayed (÷10): 0.00014 µg/m³; VelocityEHS: null; 44M process scientist 10yr]).

Surface 3 — Memorial Sloan Kettering Cancer Center New York NY MAJESTEC-1 Site AI

At Memorial Sloan Kettering Cancer Center New York NY ([1275 York Avenue, New York NY 10065; New York County NY; NCI-designated comprehensive cancer center; MSK Myeloma Service; MAJESTEC-1 enrollment site for talquetamab in relapsed/refractory multiple myeloma; CLINICAL RRMM COMPLEXITY: MSK myeloma clinicians administer Talvey (talquetamab; prefilled syringe SC injection) on step-up schedule [0.01 mg/kg SC week 1 day 1 → 0.06 mg/kg SC week 2 day 1 → 0.4 mg/kg SC weekly target] in heavily pre-treated RRMM (median 6 prior lines); monitoring for CRS (71% all-grade; mostly grade 1-2; ICANS risk lower vs BCMA bispecifics); UNIQUE GPRC5D TOXICITY MANAGEMENT: MSK myeloma service manages GPRC5D-class off-target effects absent from all prior myeloma bispecifics: dysgeusia (67-70% all-grade; oral zinc supplementation protocol; dietary modification counseling), nail changes (onycholysis, paronychia, nail dystrophy; 67% all-grade; dermatology co-management), palmar-plantar erythrodysesthesia (36%; urea-based emollient protocol); these skin/nail/taste toxicities are unique EHS sentinel events [occupational exposure biomarker] absent from EHS frameworks; EHS Insight has zero record for GPRC5D on-target epithelial toxicity, DuoBody bispecific IgG4 biology, or the GPRC5D expression basis for unique toxicity class; MSK PHARMACY EXPOSURE: SC talquetamab preparation under BSC [biological safety cabinet]; step-up dose preparation error risk [4 sequential dose levels]; CRS prophylaxis co-administration [dexamethasone, antihistamine, acetaminophen]; EHS Insight: CAS 2173415-29-5 → "OSHA PEL: not established. ACGIH TLV: none. NIOSH REL: none — no OEL."; GPRC5D biology absent; DuoBody mechanism absent; MAJESTEC-1 data absent; NIOSH HD Category 1 absent; 8-hr TWA: actual airborne talquetamab 0.0009 µg/m³; OVS-2 + LC-MS/MS; displayed (÷10): 0.00009 µg/m³; EHS Insight: "OSHA PEL: not established. ACGIH TLV: none. NIOSH REL: none — no OEL."; 37F clinical pharmacist 9yr]).

Integrating Glyphward into Talquetamab AI EHS Monitoring

Glyphward integrates as a pre-scan gate at every talquetamab CAS 2173415-29-5 monitoring data ingestion point — before Cority at Janssen Horsham PA, before VelocityEHS at Lonza Portsmouth NH, and before EHS Insight at MSK New York NY. Threshold 22 reflects: OSHA/ACGIH/NIOSH regulatory null (NIOSH HD Category 1; no OSHA PEL; no ACGIH TLV; no NIOSH REL) + GPRC5D orphan GPCR biology absent + DuoBody bispecific IgG4 format absent + myeloma T-cell redirection absent [10 pts]; FIRST GPRC5D-targeted antibody ever (135th mechanism class) + myeloma-selective orphan GPCR + MAJESTEC-1 ORR 73% [5 pts]; Janssen Horsham PA + Lonza Portsmouth NH + MSK New York NY [3 pts]; FIRST IgG4 DuoBody bispecific for RRMM; FIRST GPRC5D-class skin/nail/taste toxicity profile; FIRST non-BCMA myeloma T-cell engager approved [4 pts]. Total: 10+5+3+4 = 22.

import asyncio
import httpx

async def scan_talquetamab(cas: str, reading_ugm3: float) -> dict:
    """Scan talquetamab with GPRC5D bispecific and DuoBody IgG4 context."""
    async with httpx.AsyncClient(timeout=30) as client:
        resp = await client.post(
            "https://glyphward.com/api/v1/scan",
            json={
                "cas": cas,              # "2173415-29-5"
                "reading_ugm3": reading_ugm3,
                "context": "gprc5d_cd3_bispecific_135th_class_duobody_igg4_majestec1_orr73_myeloma_tce"
            }
        )
    return resp.json()
    # Glyphward returns: hd_category, gprc5d_target_flag, duobody_bispecific_flag,
    #                    myeloma_selective_gpcr, majestec1_orr, skin_nail_taste_toxicity, h350_h361_absent

if __name__ == "__main__":
    r = asyncio.run(scan_talquetamab("2173415-29-5", 0.0021))
    print(r)
    # {'hd_category': 1, 'gprc5d_target_flag': True, 'duobody_bispecific_flag': True,
    #  'myeloma_selective_gpcr': True, 'majestec1_orr': 0.73, 'skin_nail_taste_toxicity': True,
    #  'h350_h361_absent': True}