STREPTOZOCIN - Generic Drug Details

What are the generic drug sources for streptozocin and what is the scope of freedom to operate?

Streptozocin is the generic ingredient in one branded drug marketed by Teva Pharms Usa and is included in one NDA. Additional information is available in the individual branded drug profile pages.

Summary for STREPTOZOCIN

US Patents:	0
Tradenames:	1
Applicants:	1
NDAs:	1
Raw Ingredient (Bulk) Api Vendors:	65
Clinical Trials:	11
What excipients (inactive ingredients) are in STREPTOZOCIN?	STREPTOZOCIN excipients list
DailyMed Link:	STREPTOZOCIN at DailyMed

Recent Clinical Trials for STREPTOZOCIN

Identify potential brand extensions & 505(b)(2) entrants

Sponsor	Phase
Azienda Ospedaliera Spedali Civili di Brescia	Phase 3
Azienda Socio Sanitaria Territoriale degli Spedali Civili di Brescia	Phase 3
National Cancer Institute, France	Phase 2

See all STREPTOZOCIN clinical trials

Medical Subject Heading (MeSH) Categories for STREPTOZOCIN

Antibiotics, Antineoplastic

Anatomical Therapeutic Chemical (ATC) Classes for STREPTOZOCIN

L01AD	Nitrosoureas
L01A	ALKYLATING AGENTS
L01	ANTINEOPLASTIC AGENTS
L	Antineoplastic and immunomodulating agents

US Patents and Regulatory Information for STREPTOZOCIN

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Teva Pharms Usa	ZANOSAR	streptozocin	INJECTABLE;INJECTION	050577-001	May 7, 1982		DISCN	Yes	No

Streptozocin Market Dynamics, Patent Position, FDA Status, and Financial Trajectory

Last updated: September 6, 2026

Streptozocin, marketed in the United States as Zanosar, is an old oncology drug used primarily for malignant pancreatic islet-cell tumors and other pancreatic neuroendocrine tumors. Its commercial profile is defined by a small addressable population, hospital-based administration, limited competition, clinical utility in a rare indication, and the absence of meaningful remaining patent exclusivity. Public disclosures do not provide standalone Zanosar revenue, so its financial trajectory must be assessed through market structure, treatment volume, pricing, supply continuity, and competitive risk rather than reported product sales.

What is streptozocin and how is it used?

Streptozocin is an alkylating antineoplastic agent with selective toxicity toward pancreatic beta cells. Zanosar is supplied as a powder for intravenous administration and is used in the treatment of malignant islet-cell tumors of the pancreas, including functional and nonfunctional neuroendocrine tumors.

The FDA-approved labeling identifies streptozocin as an adjunct to surgery or as palliative treatment for progressive metastatic islet-cell tumors. Treatment is generally administered in specialized oncology settings because of renal toxicity, gastrointestinal toxicity, myelosuppression, and the need for hydration and laboratory monitoring (FDA, 2023).

FDA regulatory status

Item	Status
Active ingredient	Streptozocin
U.S. brand	Zanosar
Dosage form	Injectable powder for intravenous solution
FDA application	NDA 018431
Initial U.S. approval	1982
Primary indication	Malignant islet-cell tumors of the pancreas
Product category	Small-molecule cytotoxic oncology drug
Administration	Hospital or specialist infusion setting
Orphan-drug economics	Rare-disease demand, but original approval predates the current commercial orphan-drug framework

The product’s FDA approval predates modern requirements for pediatric exclusivity, patent-term restoration, and most contemporary orphan-drug commercial strategies. No current regulatory exclusivity period materially protects Zanosar from competition.

When does streptozocin lose exclusivity?

Streptozocin lost meaningful regulatory and patent exclusivity decades ago. The compound was developed and approved in the early era of cytotoxic oncology, and any composition-of-matter patent protection would have expired long before the current market period.

Exclusivity category	Current position
New chemical entity exclusivity	Expired
Patent-term restoration	No commercially relevant protection remains
Orphan-drug exclusivity	No current seven-year exclusivity blocking competition
Pediatric exclusivity	None identified
Data exclusivity	Expired
Marketed-product protection	Based on manufacturing, supply, regulatory history, and clinical familiarity rather than exclusivity

The commercial moat is therefore operational rather than legal. A supplier can retain market share through regulatory compliance, validated manufacturing, reliable sterile production, distributor relationships, and physician familiarity. Those barriers can delay or discourage entry, but they do not prevent an FDA-approved competitor from entering if it completes the applicable regulatory pathway.

What patents protect streptozocin?

No active U.S. composition-of-matter patent is expected to protect streptozocin. The molecule has been known and used clinically for decades. The patent opportunity is concentrated in secondary areas:

• Stable injectable formulations.
• Lyophilization and reconstitution methods.
• Manufacturing and purification processes.
• Packaging systems for cytotoxic sterile products.
• Methods for reducing renal toxicity or improving treatment scheduling.
• Combination regimens with other pancreatic neuroendocrine tumor therapies.

No currently material U.S. patent estate is publicly associated with Zanosar that would recreate branded exclusivity for the active ingredient. FDA Orange Book patent listings, where present, would be the relevant source for listed patents tied to the approved product and method of use. The commercial position of Zanosar does not appear to depend on a live Orange Book patent barrier (FDA, 2024a).

How strong is the patent estate for streptozocin?

The patent estate is weak as a blocking platform and stronger as a manufacturing-control issue.

Patent layer	Strategic strength
Active ingredient	Very weak; historical compound
Core oncology indication	Very weak; long-established use
Method of use	Limited unless directed to a narrow, newly patented regimen
Injectable formulation	Potentially moderate for a specific formulation, but not a broad product barrier
Manufacturing process	Potentially meaningful if difficult to replicate and protected by trade secrets
Packaging and handling	Low to moderate
Trade secrets and process know-how	More important than patents

The principal barrier is likely the difficulty of producing a compliant sterile cytotoxic injectable at commercial scale. That barrier can support pricing and supply control, but it is vulnerable to a competitor with adequate manufacturing capability.

What is the Orange Book status of Zanosar?

Zanosar is an NDA-approved product rather than a modern, patent-protected specialty medicine. The Orange Book is relevant for determining whether the reference product has listed patents that would require a Paragraph IV certification from an abbreviated new drug application applicant. No publicly significant active patent listing is known to create a late-stage exclusivity barrier for streptozocin.

An applicant seeking approval of a competing streptozocin injection would generally evaluate:

1. Whether the reference product remains listed as the applicable reference drug.
2. Whether any patents are listed in the Orange Book.
3. Whether the proposed product has the same active ingredient, strength, dosage form, route, and labeling.
4. Whether a Paragraph IV certification is required.
5. Whether bioequivalence and pharmaceutical-equivalence requirements can be satisfied for the injectable product.

For an old injectable, the main regulatory challenge is usually pharmaceutical equivalence, sterility, stability, container closure, and manufacturing validation rather than a patent dispute.

Are there Paragraph IV challenges to streptozocin?

No material public Paragraph IV litigation involving a competing streptozocin product is identified in the commonly used public patent-litigation record. The absence of a prominent Paragraph IV dispute is consistent with the product’s small market, limited revenue opportunity, and lack of an important live patent barrier.

A generic applicant could still face commercial obstacles even without patent litigation. These include:

• Low annual unit demand.
• High cost of sterile cytotoxic manufacturing.
• Limited inventory turnover.
• Need for reliable hospital distribution.
• Difficulty forecasting treatment volume.
• Potential reimbursement pressure.
• Risk that a new entrant would trigger price competition without generating sufficient volume.

What generic entry risks exist for Zanosar?

Generic entry risk is legally high and commercially moderate. The legal barriers are limited, but the market may not attract multiple competitors.

Risk factor	Impact on Zanosar
Patent expiry	High risk to exclusivity
Small patient population	Reduces attractiveness of entry
Sterile injectable manufacturing	Raises entry cost
Hospital procurement	Can accelerate substitution
Limited alternative therapies	Supports continued demand
Supply shortages	Can create an opening for competitors
Clinical familiarity	Supports incumbent retention
Low public revenue visibility	Makes return on investment difficult to assess

A generic entrant would most likely pursue a controlled launch rather than a large primary-care commercial strategy. The product is used in specialist centers, which reduces selling costs but also limits annual sales.

What formulations are protected by streptozocin patents?

The relevant marketed formulation is an intravenous lyophilized powder that requires reconstitution before administration. No publicly established, commercially important formulation patent appears to control the entire Zanosar market.

A formulation competitor could attempt to differentiate through:

• Ready-to-use liquid presentation.
• Improved stability after reconstitution.
• Reduced preparation time.
• Lower exposure risk for pharmacy staff.
• More convenient vial sizes.
• Improved cold-chain or room-temperature stability.
• Packaging designed for hazardous-drug handling.

These changes could support a separate product strategy, but they would not necessarily prevent approval of a conventional generic lyophilized powder.

How does streptozocin compare with competing pancreatic neuroendocrine tumor therapies?

Streptozocin competes with therapies that have broader modern clinical development and stronger commercial infrastructure. Its use is concentrated in selected pancreatic neuroendocrine tumor patients, particularly those requiring cytotoxic chemotherapy or those with progressive disease.

Therapy	Role in pancreatic neuroendocrine tumors	Commercial position
Streptozocin plus fluorouracil or doxorubicin	Cytotoxic chemotherapy for selected patients	Old, low-volume, specialized
Capecitabine plus temozolomide	Oral chemotherapy regimen	More convenient and commonly discussed in modern practice
Everolimus	Targeted therapy	Broad oncology infrastructure
Sunitinib	Targeted therapy	Approved systemic option
Somatostatin analogues	Hormonal control and antiproliferative treatment	Established specialty market
Peptide receptor radionuclide therapy	Radioligand treatment for selected receptor-positive disease	High-complexity, specialized treatment
Liver-directed therapies	Regional treatment for selected metastatic disease	Procedure-dependent

Streptozocin retains a role because pancreatic neuroendocrine tumors are heterogeneous and treatment decisions depend on tumor burden, growth rate, hormone secretion, receptor status, prior therapy, and institutional practice. Its low price relative to newer oncology agents does not eliminate its value in a narrow clinical setting.

What is the financial trajectory of streptozocin?

Public company filings do not generally disclose standalone Zanosar revenue. The product is economically immaterial relative to the sales of large pharmaceutical portfolios, so financial analysis must rely on market drivers rather than product-level revenue statements.

Revenue drivers

The product’s revenue is supported by four factors:

1. Persistent use in a rare but serious cancer population.
2. Limited direct competition in the specific streptozocin treatment niche.
3. Specialist prescribing and hospital purchasing.
4. Potential price resilience caused by the cost and risk of sterile cytotoxic manufacturing.

Revenue is constrained by:

• Small eligible-patient population.
• Infrequent treatment cycles.
• Competition from oral chemotherapy and targeted agents.
• Greater use of peptide receptor radionuclide therapy and other modern treatments.
• Generic entry potential.
• Hospital purchasing pressure.
• Product shortages or supply interruptions.

The likely long-term pattern is low absolute revenue, relatively stable demand, and episodic price or volume changes rather than rapid growth. A sudden revenue increase would most likely result from a supply disruption affecting competing products, a price revision, wider guideline adoption, or a change in treatment sequencing.

Revenue exposure by market

Geography	Commercial outlook
United States	Highest value because of specialty-drug pricing and established FDA product status
Europe	Fragmented pricing and reimbursement; national access varies
Japan	Specialist demand with local regulatory and reimbursement considerations
Emerging markets	Lower pricing but potential institutional demand
Global	Small-volume oncology market with limited public revenue reporting

Which companies are challenging streptozocin?

No major publicly visible company is known to be pursuing a high-profile patent challenge to Zanosar. The most credible competitive threat would come from a generic injectable manufacturer with existing cytotoxic sterile capacity rather than from a large pharmaceutical company seeking to develop a new branded streptozocin product.

Potential competitors would benefit from:

• Existing FDA-approved injectable manufacturing lines.
• Experience with hazardous oncology products.
• Established hospital-distribution contracts.
• Ability to sustain low-volume inventory.
• Regulatory staff familiar with abbreviated applications.

The absence of a visible challenger does not indicate strong patent protection. It more likely reflects limited market size and the economics of sterile injectable competition.

What patent litigation affects streptozocin?

No significant current U.S. patent litigation involving Zanosar is publicly evident. The litigation risk is therefore low compared with newer oncology drugs protected by composition, formulation, and method-of-use patents.

Future disputes could arise over:

• Product-specific formulation patents.
• Manufacturing-process claims.
• Labeling for a newly claimed treatment use.
• Trade-secret misappropriation.
• ANDA approval timing.
• Product quality, sterility, or manufacturing controls.

A generic applicant would likely prioritize regulatory and manufacturing readiness over patent settlement negotiations.

Are there licensing deals involving streptozocin?

No major recent licensing transaction centered on streptozocin is publicly prominent. The product’s economics are more consistent with a product-rights or portfolio-management arrangement than with a large strategic licensing deal.

A transaction involving Zanosar would likely be valued on:

• Net sales and gross margin.
• Supply reliability.
• Manufacturing ownership.
• Geographic rights.
• Hospital contracts.
• Regulatory obligations.
• Historical shortage performance.
• The risk of generic entry.

Because standalone product revenue is not publicly reported, any valuation would require confidential sales, unit, price, and supply data.

What is the generic launch scenario for streptozocin?

The most likely launch scenario is a single or small number of generic suppliers entering after confirming that no relevant Orange Book patents block approval. The initial entrant could preserve a meaningful share if it maintains reliable supply. A second entrant would increase price pressure, but the limited market may not support many suppliers.

Base-case trajectory

• Stable specialist demand.
• Limited volume growth.
• Continued reliance on the reference product or a small number of suppliers.
• Gradual pricing pressure if a generic launches.
• No material effect from biosimilars.

Downside scenario

• A competing injectable enters.
• Hospital systems switch procurement to the lowest-cost supplier.
• The incumbent loses volume and reduces production.
• Supply interruptions occur during the transition.

Upside scenario

• Greater use in pancreatic neuroendocrine tumor treatment.
• Reduced availability of alternative chemotherapy products.
• Expanded institutional adoption.
• Price increases in a constrained supply market.

Does streptozocin face biosimilar risk?

No. Streptozocin is a small-molecule drug, not a biologic. Biosimilar regulation under the Public Health Service Act does not apply. Competitive entry would occur through the generic-drug pathway, generally involving an ANDA or, depending on the product’s regulatory status and formulation, another FDA application route.

The absence of biosimilar risk does not reduce generic risk. Generic injectable competition remains the relevant threat.

Key Takeaways

• Streptozocin is an old, FDA-approved cytotoxic drug marketed in the U.S. as Zanosar.
• Its primary use is in malignant pancreatic islet-cell tumors and selected pancreatic neuroendocrine tumor patients.
• Core patent, regulatory, and data exclusivity have expired.
• No material active patent barrier or prominent Paragraph IV litigation is publicly associated with the product.
• The commercial moat rests on sterile manufacturing, regulatory history, supply reliability, and specialist prescribing.
• Standalone Zanosar revenue is not publicly disclosed.
• The market is small, specialized, and relatively stable, with limited growth potential.
• Generic entry risk is legally high but commercially moderated by low volume and sterile manufacturing costs.
• Biosimilar competition is irrelevant because streptozocin is a small molecule.
• The principal financial risk is a generic injectable entrant combined with hospital price competition.

FAQs

Is streptozocin still FDA approved?

Yes. Zanosar is associated with FDA NDA 018431 and is labeled for malignant islet-cell tumors of the pancreas.

Is Zanosar a biologic drug?

No. Zanosar contains streptozocin, a small-molecule cytotoxic agent. Generic-drug competition, not biosimilar competition, is the applicable framework.

Does Zanosar have patent protection?

No meaningful core patent protection is expected to remain. Any relevant current protection would likely involve a narrow formulation, manufacturing process, or method-of-use claim.

Why has streptozocin remained on the market despite its age?

It retains clinical utility in a rare cancer setting, has limited direct substitutes for some patients, and is used by specialist oncology centers familiar with its administration and toxicity profile.

Is streptozocin commercially attractive for a generic manufacturer?

Only selectively. The product can fit a manufacturer that already has cytotoxic sterile injectable capacity, but the limited patient population and uncertain annual demand reduce the attractiveness of a standalone investment.

References

1. U.S. Food and Drug Administration. (2023). Zanosar (streptozocin) for injection prescribing information. FDA.
2. U.S. Food and Drug Administration. (2024a). Approved drug products with therapeutic equivalence evaluations. FDA.
3. U.S. Food and Drug Administration. (2024b). Drugs@FDA: Zanosar, NDA 018431. FDA.
4. National Cancer Institute. (2024). Streptozocin. NCI Drug Dictionary.
5. National Comprehensive Cancer Network. (2024). NCCN Clinical Practice Guidelines in Oncology: Neuroendocrine and Adrenal Tumors. NCCN.
6. Teva Pharmaceuticals. (2024). Zanosar product information. Teva Pharmaceuticals.