Last updated: July 31, 2026
NegGram, the former U.S. brand for nalidixic acid, has little direct investment value. Its composition-of-matter protection expired decades ago, the product is an established generic antibacterial, and its clinical role has been displaced by newer fluoroquinolones and other urinary-tract-infection therapies. The principal investment conclusion is negative: NegGram has no identifiable patent moat, limited differentiation, weak growth prospects, and no publicly reported standalone revenue stream.
What is NegGram and who owns the drug?
NegGram is the former brand name for nalidixic acid, a first-generation quinolone antibacterial. It was marketed as an oral tablet, commonly in a 500 mg strength, for susceptible bacterial infections of the urinary tract caused primarily by gram-negative organisms.[1]
| Attribute |
NegGram |
| Active ingredient |
Nalidixic acid |
| Drug class |
First-generation quinolone antibacterial |
| Original use |
Urinary-tract infections |
| U.S. dosage form |
Oral tablet |
| Common historical strength |
500 mg |
| Original developer |
Sterling Drug |
| Current commercial structure |
Generic or legacy-product market, rather than a protected branded franchise |
| Patent position |
No commercially meaningful remaining exclusivity identified |
| FDA regulatory position |
Legacy approved product and historical reference-drug status |
| Investment profile |
Low-growth, low-moat, commodity pharmaceutical |
NegGram is not equivalent to modern fluoroquinolones such as ciprofloxacin, levofloxacin, or moxifloxacin. Nalidixic acid has narrower antibacterial activity and is generally less important in contemporary treatment guidelines.
The historical brand changed ownership through the consolidation of Sterling Drug, Winthrop, Sanofi and related pharmaceutical businesses. That ownership history does not create a current standalone investment opportunity. A pharmaceutical investor would ordinarily obtain exposure through a manufacturer, distributor, contract manufacturer, or portfolio company, not through NegGram itself.
When did NegGram lose exclusivity?
NegGram lost meaningful market exclusivity many years ago. Nalidixic acid was introduced in the 1960s, and any original composition, formulation, or use patents would have expired long before the current U.S. patent term framework became relevant.
| Exclusivity category |
NegGram status |
| Composition-of-matter patent |
Expired |
| Original branded product exclusivity |
Expired |
| Pediatric exclusivity |
None of current commercial significance |
| Orphan exclusivity |
None |
| New chemical entity exclusivity |
Expired decades ago |
| Data exclusivity |
Expired |
| Formulation exclusivity |
No commercially meaningful active protection identified |
| Method-of-use exclusivity |
No commercially meaningful active protection identified |
| Biosimilar exclusivity |
Not applicable |
The Hatch-Waxman framework grants five years of new chemical entity exclusivity for qualifying products, but NegGram predates that framework by decades.[2] Any current supplier would compete principally on regulatory compliance, supply reliability, price, and distribution.
What patents protect NegGram?
No active U.S. patent estate appears to protect NegGram as a commercially differentiated product. Nalidixic acid is an old small-molecule active ingredient, and its foundational patent rights are expired.
Patent estate assessment
| Patent category |
Commercial assessment |
| Active ingredient |
Public-domain technology |
| Salt or polymorph |
No meaningful current barrier identified |
| Tablet formulation |
Routine dosage form with low differentiation |
| Manufacturing process |
Potentially confidential know-how, but not a durable product moat |
| Method of treatment |
Historical use claims have no practical exclusivity value |
| Drug-device combination |
Not applicable |
| Packaging or delivery system |
No material protection identified |
| Orange Book patent listing |
No current commercially significant patent protection identified |
The absence of a patent does not eliminate all barriers to entry. A manufacturer still must maintain an approved application, comply with current good manufacturing practices, demonstrate product quality, and meet supply-chain requirements. Those obligations are operational barriers, not durable intellectual-property barriers.
No active patent number should be treated as an investment thesis for NegGram without a specific, current U.S. Food and Drug Administration Orange Book entry or a jurisdiction-specific patent record. The economic value of any historical NegGram patent would be negligible after expiration.
What is the Orange Book status of NegGram?
The Orange Book records FDA-approved prescription drug products and, where applicable, patents and exclusivity information.[3] NegGram is a legacy product. Its commercial significance is limited by the age of the active ingredient, the availability of alternative antibacterial agents, and the absence of meaningful remaining exclusivity.
The relevant Orange Book questions are:
- Whether the brand reference product remains actively marketed.
- Whether any abbreviated new drug applications remain approved.
- Whether the reference-listed drug has a current commercial supplier.
- Whether any patent or exclusivity entry remains attached to an approved product.
For investment analysis, the expected answer is that NegGram has no blocking Orange Book patent and no remaining regulatory exclusivity. A generic applicant would not face the same patent-certification risk associated with a recently launched branded antibiotic.
Are there Paragraph IV challenges to NegGram?
Paragraph IV litigation is not a material current risk factor for NegGram. A Paragraph IV certification is relevant when a generic applicant challenges a listed patent for a branded reference product.[4] Because NegGram’s meaningful patent protection expired decades ago, there is little economic rationale for a new Paragraph IV campaign.
| Litigation issue |
Assessment |
| Current Paragraph IV campaign |
No material current campaign identified |
| Thirty-month stay risk |
Low |
| Patent-certification risk |
Low |
| ANDA litigation value |
Low |
| Settlement leverage for the brand owner |
Minimal |
| Generic launch dispute |
More likely to involve supply or regulatory issues than patent rights |
Any future generic launch would more likely depend on whether a suitable reference-listed product and an active FDA application remain available than on a patent dispute.
What generic entry risks exist for NegGram?
Generic competition is the central commercial risk. The active ingredient is old, the dosage form is conventional, and there is no clear product differentiation.
Generic launch scenarios
| Scenario |
Probability assessment |
Commercial effect |
| Continued low-volume supply by one legacy manufacturer |
Moderate |
Stable but small market |
| Multiple generic suppliers compete on price |
Moderate |
Margin compression and possible product withdrawal |
| Product becomes unavailable in the U.S. |
Material |
Demand shifts to alternatives rather than creating durable pricing power |
| Re-launch by a specialty generic company |
Low to moderate |
Possible niche revenue, but limited moat |
| Premium branded recovery |
Very low |
No credible basis without new clinical or delivery differentiation |
The main risk is not a sudden generic launch against a high-value brand. The main risk is economic obsolescence. Suppliers may discontinue a low-volume product if manufacturing, quality-control, regulatory-maintenance, or distribution costs exceed net revenue.
How strong is the NegGram patent estate?
The patent estate is very weak.
A practical scoring framework gives NegGram the following profile:
| Factor |
Score |
Rationale |
| Composition-of-matter protection |
0/5 |
Expired |
| Formulation protection |
0/5 |
Conventional tablet |
| Method-of-use protection |
0/5 |
Historical indication |
| Regulatory exclusivity |
0/5 |
Expired |
| Manufacturing differentiation |
1/5 |
Possible process know-how, but limited defensibility |
| Brand strength |
1/5 |
Legacy recognition only |
| Clinical differentiation |
1/5 |
Narrow and dated therapeutic role |
| Switching costs |
0/5 |
Prescribers can use other antibacterials |
| Supply-chain value |
2/5 |
Potential value only if supply is constrained |
| Overall moat |
1/5 |
Commodity or legacy-product economics |
The only plausible commercial protection would come from scarcity, supplier qualification, manufacturing capability, or a regulated-market shortage. Those factors can produce temporary pricing power, but they do not substitute for patent protection.
What is the FDA regulatory status of NegGram?
The FDA historically approved nalidixic acid for urinary-tract infections caused by susceptible organisms. The drug’s label reflects the safety limitations of an older quinolone, including central nervous system effects and the potential for seizures. Antibacterial use is generally restricted by organism susceptibility and resistance considerations.[1]
Modern regulatory and clinical issues include:
- Limited relevance against contemporary resistant pathogens.
- Need for susceptibility testing.
- Safety concerns associated with quinolone-class pharmacology.
- Reduced use relative to newer antibiotics.
- Potential product discontinuation if the U.S. supply base is thin.
- Low probability of regulatory exclusivity for the legacy product.
NegGram should not be analyzed as a growth-stage anti-infective. It is an old approved product with a narrow and declining strategic role.
What formulations are protected by NegGram?
NegGram’s historical product was an immediate-release oral tablet. No high-value formulation platform is associated with the product.
| Formulation |
Commercial status |
| Immediate-release tablet |
Historical and generic formulation |
| Extended-release formulation |
No material commercial protection identified |
| Injectable formulation |
Not a core NegGram product |
| Inhaled or implantable formulation |
Not applicable |
| Combination product |
No established protected franchise |
| Specialty delivery system |
None identified |
A reformulated nalidixic acid product could theoretically generate new intellectual property if it produced a meaningful pharmacokinetic, safety, or adherence benefit. That would require new clinical development and would face weak commercial logic because physicians have access to more modern antibacterial agents.
What manufacturing and intellectual-property barriers affect NegGram?
Manufacturing barriers are modest but not zero. A supplier must control assay, impurities, dissolution, stability, microbiological quality, and batch consistency. Older antibiotics can carry supply risks if active pharmaceutical ingredient production is concentrated among a small number of manufacturers.
The relevant barriers are:
- API sourcing and qualification.
- FDA-compliant tablet manufacturing.
- Stability data for the marketed dosage form.
- Bioequivalence and product-quality documentation.
- Quality-system maintenance.
- Reliable distribution to hospitals, pharmacies, or wholesalers.
These requirements may deter casual entrants, but they do not support premium pricing. A contract manufacturer with an existing approved platform could potentially produce the product at lower incremental cost than a new entrant.
Which companies are challenging NegGram?
There is no meaningful branded-versus-generic competitive contest comparable to current markets for patented antibiotics. Competition is more likely to involve:
- Generic oral antibacterial manufacturers.
- Legacy-product suppliers.
- Specialty pharmaceutical companies that acquire low-volume approved products.
- Contract manufacturers with established oral-solid-dose capacity.
- Suppliers in non-U.S. markets where nalidixic acid remains registered.
The commercial landscape is fragmented and price-sensitive. No company appears to possess a durable strategic advantage based on NegGram’s intellectual property.
What licensing deals affect NegGram?
No major current licensing transaction is associated with NegGram as a standalone asset. Historical ownership changes involving Sterling Drug and successor pharmaceutical companies reflect corporate consolidation rather than a current value-generating license.
A licensing transaction involving nalidixic acid would likely be motivated by one of four factors:
- Access to an approved regulatory file.
- Transfer of a manufacturing source.
- Entry into a market with limited local supply.
- Acquisition of a broader legacy-product portfolio.
A standalone license would have weak economics unless it included an approved application, established distribution, or a shortage-driven market opportunity.
What patent litigation and settlement agreements affect NegGram?
No material current patent litigation or settlement agreement is associated with NegGram. The product’s age and lack of meaningful remaining patent protection reduce the likelihood of branded patent litigation.
The more relevant legal risks are ordinary pharmaceutical compliance matters:
- FDA manufacturing inspections.
- Product-quality investigations.
- Labeling compliance.
- Drug-shortage reporting.
- Contract-manufacturing disputes.
- Product-liability claims.
These risks can affect a supplier’s cost base, but they do not create an investable patent litigation catalyst.
How does NegGram compare with modern urinary-tract-infection drugs?
| Factor |
NegGram |
Modern alternatives |
| Active ingredient |
Nalidixic acid |
Nitrofurantoin, fosfomycin, trimethoprim-sulfamethoxazole, fluoroquinolones and others |
| Clinical role |
Narrow, historical |
Broader or guideline-specific roles |
| Patent protection |
None of material value |
Varies by product |
| Generic competition |
High or legacy-market competition |
Ranges from generic to protected branded products |
| Resistance position |
Limited usefulness |
Depends on pathogen and local resistance |
| Prescriber familiarity |
Historical |
Modern guideline and formulary positioning |
| Pricing power |
Very low |
Product-specific |
| Commercial growth |
Weak |
Depends on indication and exclusivity |
| Investment case |
Supply niche only |
Possible for differentiated or protected products |
The comparison is unfavorable for NegGram. A low-cost legacy antibiotic can retain niche demand, but its market is unlikely to expand without a new indication, delivery system, or supply disruption.
What revenue exposure does NegGram create?
NegGram does not appear to generate a separately disclosed revenue stream for a major public pharmaceutical company. The product is too old and commercially limited to support meaningful segment-level financial disclosure.
An investor should classify exposure as:
| Exposure type |
Assessment |
| Direct product revenue |
Likely immaterial or undisclosed |
| Gross-margin contribution |
Potentially positive only at efficient low-volume production |
| Revenue growth |
Low |
| Pricing power |
Low |
| Patent-driven revenue protection |
None |
| Regulatory catalyst value |
Low |
| Strategic portfolio value |
Possible only as part of a legacy-product bundle |
| Downside from discontinuation |
Limited for diversified companies |
A specialty-generic company could earn niche revenue if it controls an approved source in a supply-constrained market. That thesis depends on availability and operating efficiency, not on NegGram’s brand equity or patent estate.
What is the investment scenario for NegGram?
Base case
NegGram remains a low-volume legacy antibacterial with limited prescription demand and no material pricing power. A supplier earns modest contribution margin through efficient manufacturing and distribution. The product does not affect the valuation of a diversified pharmaceutical company.
Bull case
A supplier obtains an approved product, faces limited competition, and benefits from temporary scarcity or a regional supply interruption. Revenue and margins improve for a limited period. The upside remains vulnerable to new generic entrants and substitution to other antibacterials.
Bear case
Manufacturing, quality, or regulatory costs exceed product revenue. The supplier discontinues the product, and patients move to alternative therapies. Patent litigation does not provide a recovery mechanism because no meaningful exclusivity remains.
Key Takeaways
- NegGram is the legacy brand for nalidixic acid, an early quinolone antibacterial.
- Its original patents and regulatory exclusivities expired decades ago.
- No commercially meaningful active patent estate or Orange Book exclusivity supports the product.
- Paragraph IV litigation and settlement risk are low.
- Generic competition, therapeutic substitution, and possible discontinuation are the main commercial risks.
- No major current licensing deal, litigation catalyst, or separately disclosed revenue stream is tied to NegGram.
- A potential investment thesis would depend on supply scarcity, regulatory-file ownership, or portfolio-level economics.
- As a standalone pharmaceutical asset, NegGram has low strategic value and a weak investment profile.
Frequently Asked Questions
Is NegGram still prescribed in the United States?
Use is limited compared with newer antibacterial therapies. Its historical indication was susceptible urinary-tract infection, but contemporary treatment decisions generally favor agents with more relevant safety, resistance, and guideline profiles.[1]
Is nalidixic acid the same as ciprofloxacin?
No. Both belong to the quinolone family, but nalidixic acid is an older first-generation agent with narrower activity and a different clinical role.
Can a company obtain new patents on nalidixic acid?
A company cannot patent the old active ingredient as new subject matter. It could seek patents on a genuinely novel formulation, manufacturing process, combination, or treatment method, but commercial value would depend on demonstrating meaningful clinical or operational differentiation.
Does NegGram have biosimilar competition?
No. Biosimilar regulation applies to biologic products. NegGram is a conventional small-molecule drug and competes through generic-drug pathways.
Could a drug shortage make NegGram attractive to investors?
A shortage could create temporary value for an approved supplier with reliable manufacturing capacity. That opportunity would be operational and supply-driven, not protected by a durable patent or exclusivity right.
References
- U.S. Food and Drug Administration. (n.d.). NegGram (nalidixic acid) prescribing information. FDA labeling database.
- U.S. Food and Drug Administration. (n.d.). New chemical entity exclusivity. FDA.
- U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations. FDA, Orange Book.
- U.S. Food and Drug Administration. (n.d.). Abbreviated new drug application approvals and patent certifications. FDA.
