Plicamycin - Generic Drug Details

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

Plicamycin is the generic ingredient in one branded drug marketed by Pfizer and is included in one NDA. Additional information is available in the individual branded drug profile pages.

Summary for plicamycin

US Patents:	0
Tradenames:	1
Applicants:	1
NDAs:	1
Raw Ingredient (Bulk) Api Vendors:	25
DailyMed Link:	plicamycin at DailyMed

Medical Subject Heading (MeSH) Categories for plicamycin

Antibiotics, Antineoplastic

Fluorescent Dyes

Nucleic Acid Synthesis Inhibitors

Protein Synthesis Inhibitors

Anatomical Therapeutic Chemical (ATC) Classes for plicamycin

L01DC	Other cytotoxic antibiotics
L01D	CYTOTOXIC ANTIBIOTICS AND RELATED SUBSTANCES
L01	ANTINEOPLASTIC AGENTS
L	Antineoplastic and immunomodulating agents

US Patents and Regulatory Information for plicamycin

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Pfizer	MITHRACIN	plicamycin	INJECTABLE;INJECTION	050109-001	Approved Prior to Jan 1, 1982		DISCN	No	No

Plicamycin Market Dynamics and Financial Trajectory: Mithracin Status, Commercial Decline, and Patent Outlook

Last updated: September 5, 2026

Plicamycin, also known as mithramycin, is an older antineoplastic antibiotic that lost commercial relevance after newer cancer therapies displaced it and manufacturing became difficult to justify for a narrow, toxicity-limited market. Its U.S. commercial status is discontinued, its historical patent estate is expired, and no meaningful current branded or generic revenue stream is publicly reported. The main residual value is clinical and research-related rather than commercial.

What is plicamycin and how was it used?

Plicamycin is a cytotoxic aureolic-acid antibiotic derived from Streptomyces plicatus. It binds DNA in association with divalent metal ions and inhibits transcription. The mechanism produces antitumor activity but also creates substantial systemic toxicity.

Historically, plicamycin was used for:

• Testicular tumors
• Hypercalcemia associated with malignancy
• Hypercalciuria associated with malignancy
• Selected leukemias and solid tumors before modern targeted and cytotoxic regimens became standard

The drug was marketed in the United States under the brand name Mithracin as an intravenous injectable product. The National Cancer Institute identifies plicamycin as a former cancer treatment that is no longer commonly used because of toxicity and the availability of more effective therapies.[1]

Its clinical limitations included thrombocytopenia, hepatotoxicity, renal toxicity, gastrointestinal effects, mucosal injury, and bleeding risk. These risks constrained both dose intensity and repeat treatment.

What is the FDA regulatory status of plicamycin?

Plicamycin is not an active mainstream FDA commercial product. Historical U.S. use centered on an approved injectable formulation, but the product is listed in drug databases as discontinued.

Regulatory issue	Plicamycin status
Active U.S. branded product	No
Historical brand	Mithracin
Dosage form	Intravenous injection
Primary U.S. indications	Testicular tumors; malignancy-associated hypercalcemia and hypercalciuria
Current routine oncology use	No
FDA Orange Book commercial relevance	Minimal or none
Biosimilar pathway	Not applicable
Current broad generic supply	No established U.S. market

The FDA Orange Book is principally relevant to approved drug products with active marketing and listed patents or exclusivities. Plicamycin does not have a current commercial franchise comparable to products such as pembrolizumab, denosumab, or modern oral targeted therapies.[2]

The product’s regulatory history is therefore more important as a record of historical approval than as a source of current exclusivity.

When did plicamycin lose exclusivity?

Plicamycin lost practical exclusivity decades ago. Any original composition, manufacturing, or use patents would have expired long before the current period under the patent terms applicable when the drug was developed.

Plicamycin’s commercial decline was driven by market obsolescence rather than a single patent cliff. The relevant sequence was:

Period	Commercial development
1960s	Clinical development and regulatory introduction
1970s	Use in testicular cancer and malignancy-associated hypercalcemia
1980s-1990s	Substitution by improved chemotherapy, bisphosphonates, and other supportive-care treatments
2000s	Narrowing clinical use and declining commercial rationale
Current period	Discontinued U.S. product with no meaningful exclusivity value

The product is not a current patent-expiry event. It is a post-exclusivity, post-commercialization asset.

What patents protect plicamycin?

No current U.S. patent estate appears to protect plicamycin as a commercial drug. Historical protection would have covered some combination of:

• The plicamycin molecule
• Antibiotic production by microbial fermentation
• Purification and formulation methods
• Therapeutic use in malignant disease
• Injectable administration

Those protections are expired. Any newly filed patent would need to claim a genuinely new formulation, manufacturing process, delivery system, or clinical use. A patent on plicamycin itself would not be available because the active ingredient is long-established prior art.

What formulation patents protect plicamycin?

The historical product was an injectable formulation. Potential formulation claims could cover stability, lyophilization, excipient selection, concentration, reconstitution, or controlled delivery. Such claims would need to provide a novel and non-obvious technical solution.

A reformulated plicamycin product could theoretically seek new intellectual-property protection, but the commercial case is weak. The formulation would still face:

• A narrow addressable patient population
• Known systemic toxicity
• Competition from safer standards of care
• Manufacturing complexity for a sterile cytotoxic injectable
• Limited physician familiarity
• Reimbursement pressure

No active formulation patent has established a current U.S. plicamycin franchise.

What manufacturing and intellectual-property barriers remain?

The active ingredient is produced through fermentation and requires downstream purification. Commercial manufacturing would also require validated sterile injectable operations, cytotoxic handling, quality controls, and a reliable supply chain.

The main barriers are operational rather than patent-based:

1. Re-establishing a compliant source of active pharmaceutical ingredient.
2. Demonstrating consistent potency and impurity control.
3. Validating sterile filling and container closure.
4. Managing occupational exposure to a cytotoxic compound.
5. Generating contemporary clinical and stability data.
6. Obtaining a commercial return large enough to support the program.

These requirements are material for a drug with limited likely demand.

How did plicamycin’s market dynamics change?

Plicamycin’s market followed the typical trajectory of an older cytotoxic drug displaced by medicines with stronger efficacy, better tolerability, or easier administration.

Oncology displacement

In testicular cancer, combination chemotherapy regimens based on cisplatin became the dominant treatment framework. Plicamycin did not retain a competitive role against modern curative regimens.

Hypercalcemia displacement

For malignancy-associated hypercalcemia, bisphosphonates and later denosumab offered more manageable treatment strategies. These products created a stronger competitive barrier because they were supported by contemporary clinical development, established reimbursement, and broader clinical adoption.

Safety-driven erosion

Plicamycin’s hepatic, renal, hematologic, and gastrointestinal toxicities reduced its attractiveness. Its narrow therapeutic index also limited its use as a salvage option.

Manufacturing economics

Plicamycin required a specialized injectable supply chain but lacked a large volume market. Once demand fell, fixed manufacturing, quality, regulatory, and distribution costs became difficult to recover.

What was plicamycin’s financial trajectory?

There is no reliable public revenue series for plicamycin comparable to the reporting available for major current pharmaceutical products. Historical product-level sales were not consistently disclosed, and the drug was marketed before modern product-level transparency became common.

The financial trajectory can nevertheless be characterized:

Financial phase	Revenue profile	Main driver
Launch and early adoption	Commercial oncology revenue	Limited but established use in testicular cancer and hypercalcemia
Mature period	Stable-to-declining revenue	Clinical substitution and toxicity
Late commercial period	Low-volume revenue	Restricted use and shrinking prescriber base
Post-discontinuation	No meaningful branded revenue	Product withdrawal and market exit
Current period	No established U.S. revenue stream	Lack of routine commercial supply

Plicamycin was never positioned as a durable platform asset. It lacked the characteristics that support long-term pharmaceutical growth:

• No broad chronic-use indication
• No large maintenance population
• No differentiated delivery technology
• No active patent-based pricing power
• No expanding label strategy
• No companion diagnostics or combination franchise
• No established lifecycle-management program

What generic entry risks exist for plicamycin?

Generic entry risk is commercially immaterial because the principal issue is not competition against an active branded product. The issue is whether a manufacturer would re-enter or maintain supply for a small, specialized market.

A potential generic or unbranded entrant would face:

• Limited demand
• High sterile-manufacturing costs
• Cytotoxic handling requirements
• Potentially difficult bioequivalence and quality documentation
• Low pricing power
• Procurement volatility
• Greater clinical availability of alternative medicines

If a company revived plicamycin, it would likely pursue an abbreviated regulatory strategy only if an eligible reference product and adequate regulatory pathway were available. Otherwise, the sponsor might need a more complex application supported by updated chemistry, manufacturing, and controls data, plus clinical justification for the intended use.

Are there Paragraph IV challenges or plicamycin patent lawsuits?

No active, commercially material Paragraph IV campaign is associated with plicamycin. Paragraph IV litigation is generally relevant when a generic applicant challenges unexpired patents listed for an active reference drug. Plicamycin’s historical patents are expired, and the product has no current high-value Orange Book exclusivity position.

No ongoing major U.S. patent litigation or settlement agreement materially affects plicamycin’s market outlook.

This distinguishes plicamycin from active oncology products whose patent estates generate abbreviated new drug application litigation, launch-at-risk disputes, or negotiated generic-entry dates.

Does plicamycin have biosimilar risk?

No. Plicamycin is a small-molecule antibiotic, not a biologic. Biosimilar regulation under the Public Health Service Act does not apply.

Any future competitor would be a generic or otherwise independently approved small-molecule product, not a biosimilar. The commercial issue would be product reintroduction and manufacturing viability rather than biologic interchangeability.

Which companies compete with plicamycin?

Plicamycin’s relevant competitors are therapeutic substitutes rather than direct products with the same active ingredient.

Clinical use	Main competitive categories
Testicular cancer	Cisplatin-based chemotherapy, etoposide, bleomycin, surgery, radiotherapy in selected settings
Malignancy-associated hypercalcemia	Intravenous bisphosphonates, denosumab, hydration, treatment of the underlying cancer
Experimental anticancer use	Modern targeted agents, immunotherapies, and disease-specific regimens

The strongest competitive pressure comes from established treatment algorithms supported by current guidelines, broad supply, and physician familiarity.

What licensing deals affect plicamycin?

No major current licensing transaction is publicly associated with plicamycin. The compound’s historical development predates the licensing structures used for modern oncology assets, and the current product lacks an active commercial franchise.

A new license would be more likely to concern:

• A novel plicamycin analog
• A targeted delivery system
• A new formulation
• A research application
• A combination regimen
• A fermentation or production technology

A license covering legacy plicamycin alone would have limited strategic value unless paired with a differentiated clinical or manufacturing platform.

How strong is the plicamycin patent estate?

The commercial patent estate is weak because the relevant historical rights have expired and no active exclusivity appears to support a current branded product.

Patent-estate dimension	Assessment
Core compound protection	Expired
Historical use patents	Expired
Formulation protection	No material active estate identified
Manufacturing protection	Any historical rights likely expired
Orange Book leverage	None of current commercial significance
Freedom-to-operate value	More relevant than exclusionary value
Litigation leverage	Very low
Lifecycle-management potential	Low unless based on a genuinely novel platform

The principal intellectual-property question for a future sponsor would be freedom to operate around new formulations, manufacturing processes, analogs, and delivery systems. Legacy plicamycin itself provides little exclusionary value.

What is the likely future market for plicamycin?

The base case is continued commercial inactivity in the United States. Any future market would likely be niche and event-driven, such as:

• Limited-access hospital use
• Investigational oncology studies
• Research into transcriptional inhibitors
• Development of plicamycin analogs
• Orphan or salvage indications supported by new clinical evidence

A commercially viable revival would require a new value proposition. Historical efficacy alone is unlikely to support re-entry because current alternatives have stronger clinical positioning and more established supply chains.

The more credible asset opportunity is a next-generation derivative that retains plicamycin’s molecular activity while improving tumor selectivity, tolerability, pharmacokinetics, or delivery. That type of program could generate new composition-of-matter and method-of-use patents. It would also require substantial preclinical and clinical investment.

Key Takeaways

• Plicamycin, or mithramycin, is a discontinued historical oncology drug.
• Its former uses included testicular tumors and malignancy-associated hypercalcemia.
• The U.S. product was an intravenous injectable marketed as Mithracin.
• Historical patents are expired, and no meaningful active Orange Book estate supports current pricing power.
• There is no relevant biosimilar issue because plicamycin is a small molecule.
• Paragraph IV litigation, active patent disputes, and settlement agreements are not material to the current market.
• Revenue has fallen from historical oncology use to no meaningful publicly reported current commercial stream.
• The main barriers to re-entry are clinical obsolescence, toxicity, sterile manufacturing, and limited demand.
• A future investment case would depend on a novel formulation, delivery platform, analog, or new clinical indication rather than the legacy molecule alone.

FAQs About Plicamycin Market and Patent Status

Is plicamycin still available in the United States?

Plicamycin is not a routinely marketed U.S. oncology product. The historical Mithracin product has been discontinued.

What company originally marketed Mithracin?

Mithracin was historically marketed in the United States by Pfizer. Current commercial ownership and supply arrangements do not create an active branded franchise.

Can a generic company launch plicamycin?

A company could potentially pursue regulatory approval for a plicamycin product, but commercial viability would depend on re-establishing manufacturing, regulatory support, and adequate demand. Expired patents would not prevent entry.

Is plicamycin used for hypercalcemia today?

Plicamycin has largely been displaced by bisphosphonates, denosumab, hydration, and treatment of the underlying malignancy. Its historical hypercalcemia role does not represent a material current market.

Does plicamycin have value as an oncology licensing asset?

Legacy plicamycin has limited standalone licensing value. A stronger transaction case would involve a new analog, targeted delivery approach, formulation, or clinically differentiated use supported by new patent rights.

References

1. National Cancer Institute. (n.d.). Plicamycin. NCI Dictionary of Cancer Terms. https://www.cancer.gov/publications/dictionaries/cancer-terms
2. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book. https://www.accessdata.fda.gov/scripts/cder/ob/
3. U.S. National Library of Medicine. (n.d.). Plicamycin. PubChem. https://pubchem.ncbi.nlm.nih.gov/compound/Plicamycin
4. U.S. National Library of Medicine. (n.d.). Mithracin. DailyMed. https://dailymed.nlm.nih.gov/
5. National Cancer Institute. (n.d.). Plicamycin: Drug information. NCI Drug Dictionary. https://www.cancer.gov/publications/dictionaries/cancer-drug/def/plicamycin