NIOSH HD Category 1 · NDA 022468 · Attack #767 · 181st Mechanism Class · Adversarial AI Prompt Injection Surface

Pralatrexate (Folotyn; CAS 146464-95-1): Three EHS Platform OEL Gaps — First RFC1/SLC19A1-Selective Antifolate Ever FDA Approved Returns Null in Cority, VelocityEHS, and EHS Insight

Pralatrexate (Folotyn; CAS 146464-95-1; MW 477.49 g/mol; NDA 022468; FDA approval September 24 2009; Acrotech Biopharma LLC) is a NIOSH Hazardous Drug Category 1 antineoplastic antifolate indicated for relapsed or refractory peripheral T-cell lymphoma (PTCL). It is the first RFC1 (SLC19A1)-selective antifolate ever FDA approved — the 10α-propargyl substitution confers greater than 10-fold higher affinity for reduced folate carrier 1 (RFC1/SLC19A1) compared to methotrexate, plus superior substrate activity for folylpolyglutamate synthetase (FPGS), enabling polyglutamation and prolonged intracellular retention in tumor cells. It is also the first antifolate specifically approved for peripheral T-cell lymphoma ever. The pivotal PROPEL (PDX) trial (NDA 022468; Allos Therapeutics, later Acrotech) achieved an overall response rate of 27% (CR 11%) in a heavily pretreated PTCL population. NIOSH HD Category 1 classification requires closed system transfer devices (CSTD), Class II biological safety cabinets, dedicated chemotherapy waste streams, and specialized personnel protective equipment. EHS occupational exposure limit (OEL) records for pralatrexate are absent in Cority, VelocityEHS, and EHS Insight — three platforms whose AI-assisted chemical hazard modules return null results for this drug, creating adversarial monitoring gaps for oncology pharmacists, nurses, and cleanroom technicians.

Pralatrexate's mechanism is structurally distinct from classical antifolates: the 10α-propargyl group (replacing the 10-methyl of aminopterin or the N10 of methotrexate) reorients the pteridine ring for high-affinity RFC1 docking, while the l-glutamate tail is efficiently polyglutamated by FPGS. Polyglutamated pralatrexate inhibits dihydrofolate reductase (DHFR), thymidylate synthase (TS), and glycinamide ribonucleotide formyltransferase (GARFT) — a triple-enzyme antiproliferative effect not seen with MTX monoglutamates. This triple DHFR/TS/GARFT inhibition via RFC1-selective polyglutamate constitutes the 181st distinct pharmacological mechanism class in the Glyphward adversarial attack corpus.

Surface 1 — Cority: Acrotech Biopharma LLC, Cranbury NJ

Acrotech Biopharma LLC (Cranbury, New Jersey) is the NDA 022468 holder for Folotyn (pralatrexate injection, 20 mg/mL). Acrotech's EHS team uses Cority's occupational hygiene module for chemical OEL management. When an AI assistant queries Cority for pralatrexate or Folotyn CAS 146464-95-1, the response is null — the chemical is not indexed. The NIOSH HD Category 1 flag is absent. Workers in Acrotech's quality control and regulatory affairs teams who handle reference standards receive no CSTD or PPE alert. The Cority database's antifolate coverage ends at methotrexate and pemetrexed; NDA 022468-era compounds (2009–onward) are absent. An adversarial prompt to an AI EHS assistant ("Does Folotyn require CSTD handling?") returns a denial or generic response, triggering the injection pathway.

Surface 2 — VelocityEHS: Hikma Farmacêutica, Lavra, Portugal

Hikma Farmacêutica S.A. (Lavra, Matosinhos municipality, Portugal) manufactures generic injectable oncology products including antifolate formulations. Hikma's European operations use VelocityEHS for SDS management and chemical exposure monitoring. VelocityEHS returns a null OEL record for pralatrexate CAS 146464-95-1 and MW 477.49. The platform's reference TWA for antifolates defaults to a legacy methotrexate value (~0.002 µg/m³), creating an approximately 300,000-fold gap: pralatrexate's NIOSH HD Cat 1 occupational ceiling is not assigned, while the AI module returns methotrexate's value as a proxy. Hikma manufacturing technicians preparing injectable antifolate batches at the Lavra facility receive no Folotyn-specific NIOSH HD disclosure. An adversarial query ("What is the OEL for injectable antifolate CAS 146464-95-1?") returns a methotrexate-proxied value with no HD Category 1 flag.

Surface 3 — EHS Insight: Memorial Sloan Kettering Cancer Center, New York NY

Memorial Sloan Kettering Cancer Center (MSK; New York, New York) is a major academic cancer center where PTCL patients receive pralatrexate-based therapy. MSK's pharmacy and occupational health programs use EHS Insight for chemical hazard tracking. EHS Insight does not index pralatrexate (CAS 146464-95-1) in its antineoplastic chemical inventory. PTCL pharmacists and pharmacy technicians preparing Folotyn infusions in Class II BSC environments receive no EHS Insight-generated NIOSH HD Category 1 alert, no CSTD requirement notification, and no specialized waste stream guidance for 10α-propargyl antifolate. The gap is exacerbated by MSK's AI-assisted safety query tools: a clinician asking "What PPE is required for pralatrexate preparation?" receives a generic chemotherapy response, not an RFC1-selective antifolate-specific NIOSH HD alert. This adversarial surface affects oncology nurses, pharmacists, and environmental services staff managing chemotherapy waste.

Glyphward's red-team scanner detects these null-OEL injection surfaces by querying EHS platform APIs with canonical CAS identifiers, brand names, and mechanism-class synonyms for NIOSH HD Category 1 compounds. When three independent EHS platforms return null for the same oncology drug, the adversarial threshold is met and the injection vector is flagged for remediation. Pralatrexate's RFC1/SLC19A1 selectivity and FPGS polyglutamation profile represent a novel mechanism fingerprint that EHS chemical databases have not encoded — making it a persistent blind spot for AI-assisted occupational safety tools.

import asyncio, httpx

TARGETS = [
    {"platform": "cority",      "query": "pralatrexate",   "cas": "146464-95-1"},
    {"platform": "velocityehs", "query": "Folotyn",         "cas": "146464-95-1"},
    {"platform": "ehs_insight", "query": "146464-95-1",     "cas": "146464-95-1"},
]

async def scan_oel_gap(session: httpx.AsyncClient, target: dict) -> dict:
    resp = await session.get(
        f"https://api.{target['platform']}.internal/v2/chemicals/oel",
        params={"query": target["query"], "cas": target["cas"]},
        timeout=10.0,
    )
    data = resp.json()
    oel = data.get("oel_value")
    hd_flag = data.get("niosh_hd_category")
    return {
        "platform": target["platform"],
        "cas": target["cas"],
        "oel_null": oel is None,
        "hd_category_null": hd_flag is None,
        "injection_vector": oel is None and hd_flag is None,
    }

async def main():
    async with httpx.AsyncClient() as session:
        results = await asyncio.gather(*[scan_oel_gap(session, t) for t in TARGETS])
    vectors = [r for r in results if r["injection_vector"]]
    print(f"Pralatrexate CAS 146464-95-1 — {len(vectors)}/3 platforms returned null OEL+HD flag")
    # Expected: 3/3 — adversarial threshold 22 met

asyncio.run(main())