Streptozocin

證據等級: L5

預測適應症: 10 個

Streptozocin: From Undocumented Indication to Predicted Lymphosarcoma (Historical Antineoplastic Reuse)

One-Sentence Summary

Streptozocin’s original approved indication is not documented in this evidence pack (data gap), and detailed mechanism-of-action data is also missing. The TxGNN model’s highest-scoring prediction — relapsing-remitting multiple sclerosis — is explicitly flagged in the model’s own rationale as a network co-occurrence artifact, not a genuine drug-disease signal (the only supporting paper tested an unrelated MS drug in a streptozocin-induced diabetes rat model). Among the 10 candidates evaluated, the only one with real historical human evidence is lymphosarcoma, supported by 1970s–80s Phase I/clinical studies of streptozocin itself (not an analog), currently rated L3 / Proceed with Guardrails — though a blocking safety data gap prevents any decision from proceeding today.

Quick Overview

Item	Content
Original Indication	Not available — `original_indications` is empty in the evidence pack
Predicted New Indication	Lymphosarcoma (best-evidenced candidate; TxGNN’s top-ranked prediction, relapsing-remitting MS, is flagged as a likely false positive — see below)
TxGNN Prediction Score (Lymphosarcoma)	99.95% (rank 1791 of full candidate list)
Evidence Level	L3 (Lymphosarcoma)
US Market Status	Not Marketed
Number of NDAs	0
Recommended Decision	Hold — blocked pending safety/label data (see DG001); candidate-level evidence alone would support “Proceed with Guardrails”

Why is This Prediction Reasonable?

Currently, detailed mechanism-of-action data is not available in this evidence pack (DG002). Based on information embedded in the model’s own rationale text, streptozocin is a nitrosourea-class alkylating/DNA-methylating agent. Its best-known toxicological property — selective destruction of pancreatic β-cells via the GLUT2 transporter — is used experimentally to induce diabetes in animal models; this is a toxicological tool use, not a treated indication, and should not be confused with the drug’s clinical oncology history.

Separately from the GLUT2/diabetes-model mechanism, the DNA-alkylating action of nitrosoureas has historically supported use as broad-spectrum cytotoxic chemotherapy. This is the basis for the lymphosarcoma signal: streptozocin itself (not merely a structural analog) was directly tested in lymphoma patients in the 1970s, with reported antitumor activity (PMID 4371075) and tolerability data from a Phase I continuous-infusion study (PMID 160836). This is materially different from most of the other 9 candidates in this pack, where either no literature exists at all, or the cited literature tests chlorozotocin (a related but distinct nitrosourea analog) rather than streptozocin itself.

Important caveat on the top-ranked prediction: TxGNN’s #1 candidate by score, relapsing-remitting multiple sclerosis, is explicitly annotated in the evidence pack as lacking any plausible mechanistic link. The single supporting citation (PMID 28162947) studies fingolimod (FTY720), an approved MS drug, in a streptozocin-induced diabetic rat model of erectile dysfunction — streptozocin appears there only as a disease-induction tool, not as a treatment. This is a textbook example of a knowledge-graph co-occurrence artifact and should not be interpreted as a real repurposing signal.

Predicted Indications Overview (All 10 Candidates)

Rank	Disease	TxGNN Score	Evidence Level	Decision Stage	Recommendation	Note
1	Relapsing-remitting multiple sclerosis	99.97%	L5	S0	Hold	Flagged as false positive — unrelated drug tested in STZ-diabetes model
2	Small cell lung carcinoma	99.97%	L2	S1	Hold	Direct STZ trials (PMID 229984, 148321) were negative
3	Pulmonary blastoma	99.97%	L5	S0	Hold	No literature
4	Well-differentiated fetal adenocarcinoma of the lung	99.96%	L5	S0	Hold	No literature
5	Hereditary breast/ovarian cancer syndrome	99.96%	L5	S0	Hold	Not a single-tumor entity; no rationale for single-agent alkylator
6	Primary pulmonary lymphoma	99.96%	L4	S0	Hold	Only pharmacokinetic review, no disease-specific data
7	Lymphosarcoma	99.95%	L3	S2	Proceed with Guardrails	Direct human evidence with STZ itself (1970s–80s)
8	Rhabdomyosarcoma	99.95%	L5	S0	Hold	No literature
9	Parameningeal embryonal rhabdomyosarcoma	99.95%	L5	S0	Hold	No literature
10	Embryonal extrahepatic bile duct rhabdomyosarcoma	99.94%	L5	S0	Hold	No literature

Clinical Trial Evidence

Currently no related clinical trials registered for lymphosarcoma or any of the 10 predicted indications (all clinical_trials and ictrp_trials arrays are empty in this evidence pack).

Literature Evidence (Lymphosarcoma — the recommended candidate)

PMID	Year	Type	Journal	Key Findings
4371075	1974	Clinical Study	Cancer	Reports clinical antitumor activity and toxicity of streptozotocin (NSC-85998)
160836	1979	Phase I	Cancer Treatment Reports	Continuous IV infusion of STZ (~3.4 g/m² over 5-6 days/month) in advanced cancer; renal and GI toxicity were dose-limiting
6211231	1982	Phase II (Analog: chlorozotocin)	Cancer Treatment Reports	11% objective response in non-Hodgkin’s lymphoma patients (chlorozotocin, not STZ itself — analog data)
6234984	1984	Case Report	Cancer	STZ used in third trimester of pregnancy as part of combination regimen for diffuse histiocytic lymphoma; successful pregnancy outcome

For reference — Literature on the second-strongest candidate (Small Cell Lung Carcinoma, rank 2)

Two direct Phase II trials of streptozotocin itself were explicitly negative:

PMID 229984 — “Streptozotocin: an inactive agent in small cell carcinoma” (0/56 objective responses across pooled literature)
PMID 148321 — “Streptozotocin in advanced small cell bronchogenic carcinoma: an ineffective nonmyelosuppressive agent”

This candidate is not recommended despite its favorable TxGNN score, because the direct clinical evidence contradicts the prediction.

US Market Information

This drug is currently not marketed under this profile (market_status = 未上市), and total_licenses = 0. No NDA/license records are available in the evidence pack.

Cytotoxicity

Streptozocin’s historical clinical use as a nitrosourea alkylating agent (confirmed by NCI compound number NSC-85998 in the literature) supports classification as an antineoplastic/cytotoxic agent.

Item	Content
Cytotoxicity Classification	Conventional cytotoxic (Nitrosourea alkylating/DNA-methylating agent)
Myelosuppression Risk	Notably low relative to other alkylators — PMID 148321 explicitly describes STZ as an “ineffective nonmyelosuppressive agent” in the SCLC setting
Emetogenicity Classification	Not formally classified in the evidence pack; renal and gastrointestinal toxicity were reported as dose-limiting in Phase I data (PMID 160836) — please refer to the package insert
Monitoring Items	Renal function (creatinine/BUN — nephrotoxicity noted as dose-limiting), CBC/differential, liver function, electrolytes
Handling Protection	Cytotoxic drug handling precautions required given confirmed historical use as a chemotherapy agent

Safety Considerations

Please refer to the package insert for safety information. key_warnings, contraindications, and DDI data are all unavailable in this evidence pack (DG001, Blocking severity — TFDA label has not yet been sourced/parsed).

Conclusion and Next Steps

Decision: Hold

Rationale: A blocking data gap (DG001 — missing TFDA label/warnings) prevents this candidate from entering the S1 safety review stage regardless of indication. Separately, the model’s top-scoring prediction (multiple sclerosis) is explicitly identified in the evidence as a knowledge-graph artifact rather than a genuine signal, and should not be pursued. Among the remaining candidates, only lymphosarcoma has direct historical human evidence with streptozocin itself, but this evidence is 40-50 years old with no modern RCT validation — insufficient on its own to override the outstanding safety data gap.

To proceed, the following is needed:

TFDA (or equivalent) product label with warnings/contraindications (DG001 — Blocking)
Formal mechanism-of-action confirmation from DrugBank or primary literature (DG002)
If pursuing the lymphosarcoma signal: a search for modern (post-1990) clinical data on streptozocin in lymphoma, given current evidence predates modern lymphoma treatment standards
Clarification of the drug’s actual original approved indication(s), currently undocumented in this evidence pack
Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.