Last updated: August 9, 2026
Lomustine is a mature oral alkylating agent with a concentrated U.S. commercial model. The drug has no meaningful new-molecule patent protection, but its U.S. market has remained commercially durable because of limited treatment alternatives, low patient volume, oncology prescribing familiarity, and a historically high branded price. Gleostine, the U.S. branded product, is marketed by NextSource Pharmaceuticals. Financial performance has been driven more by price, reimbursement, and access management than by clinical volume growth.
What is lomustine and how is it used?
Lomustine, also known as CCNU, is an oral nitrosourea chemotherapy. It crosses the blood-brain barrier and is used in central nervous system malignancies and selected hematologic cancers.
The FDA-approved indication for Gleostine is treatment of patients with primary or metastatic brain tumors who have already received appropriate surgical and radiotherapy treatment. The label also identifies Hodgkin lymphoma use after disease progression on combination chemotherapy. Lomustine is often used off-label in recurrent glioblastoma and other recurrent high-grade gliomas.[1]
| Attribute |
Lomustine |
| Active ingredient |
Lomustine |
| Chemical class |
Nitrosourea alkylating agent |
| U.S. brand |
Gleostine |
| U.S. NDA |
017803 |
| Dosage form |
Oral capsules |
| U.S. strengths |
10 mg, 40 mg, and 100 mg |
| Original FDA approval |
1976 |
| Primary commercial indications |
Brain tumors; relapsed or refractory Hodgkin lymphoma |
| Administration |
Intermittent oral dosing, generally every six weeks |
| Principal manufacturer in the U.S. |
NextSource Pharmaceuticals |
| Biosimilar pathway |
Not applicable |
| Generic pathway |
ANDA under Section 505(j) of the Federal Food, Drug, and Cosmetic Act |
Lomustine has a narrow therapeutic index. Delayed and cumulative myelosuppression is a major safety issue, which constrains dosing and requires blood-count monitoring. The product is also subject to prescription handling and oncology pharmacy controls.[1]
How large is the lomustine market?
The global lomustine market is a small specialty oncology market, while U.S. revenue has historically represented the most economically important segment.
Publicly available sources do not provide a consistent, audited global market-size series for lomustine. The commercial market is difficult to measure because generic lomustine is available in some non-U.S. markets, hospital procurement data are fragmented, and U.S. product revenue is not separately reported by a public operating company.
The main market characteristics are:
- Low absolute patient volume.
- High per-patient treatment cost in the U.S.
- Concentrated branded supply.
- Limited substitution in recurrent brain tumors.
- Heavy dependence on oncology reimbursement and specialty distribution.
- Slow clinical volume growth because lomustine is primarily used after prior treatment failure.
The addressable population is tied to recurrent glioblastoma, other malignant gliomas, metastatic brain tumors, and selected relapsed Hodgkin lymphoma patients. The drug is not a broad first-line oncology product. Its demand therefore tracks disease incidence and recurrence rates rather than general prescription growth.
What is the financial trajectory for Gleostine and lomustine?
Gleostine’s U.S. financial trajectory has been shaped by a major price increase after NextSource acquired U.S. commercialization rights. Public reporting found that the price of a typical lomustine dose rose from approximately $50 before the acquisition to several hundred dollars per capsule and later to more than $1,000 per capsule, depending on strength and time period.[2][3]
The price strategy produced substantial revenue growth without a comparable increase in treated-patient volume. The economic model depended on:
- U.S. branded pricing;
- reimbursement from Medicare, commercial insurers, and oncology practices;
- specialty pharmacy distribution;
- limited competition for the U.S. marketed product;
- clinical use in patients with few remaining treatment options.
A precise standalone revenue history is not available because NextSource is privately held and does not publish a full public-company income statement dedicated to Gleostine. Estimates cited in policy and media analyses have placed annual U.S. Gleostine revenue in the tens to low hundreds of millions of dollars, depending on the year, price assumptions, and whether gross sales or net revenue is measured.[2][3]
Financial trajectory by commercial phase
| Period |
Commercial development |
Financial effect |
| Before 2013 |
Mature, low-priced chemotherapy with limited commercial investment |
Low revenue per patient |
| 2013 onward |
NextSource acquired U.S. commercialization rights and raised the price materially |
Sharp revenue expansion without major volume growth |
| 2016-2019 |
Continued price increases and heightened payer scrutiny |
High gross-revenue potential; greater access and policy risk |
| 2020-2022 |
Oncology utilization was affected by pandemic-related diagnosis and treatment disruption; recurrent-brain-tumor demand remained |
Mixed volume performance, continued price dependence |
| 2023 onward |
Generic-entry and reimbursement pressure became more important strategic variables |
Greater risk to price, market share, and margins |
The key financial distinction is between market size and revenue quality. Lomustine can generate high revenue per patient, but its market is vulnerable to a single generic entrant, payer restrictions, price concessions, and substitution by newer therapies.
When does lomustine lose exclusivity?
Lomustine’s original molecule and original FDA approval are decades old. The U.S. product does not depend on an active composition-of-matter patent for exclusivity.
The relevant exclusivity dates are:
| Exclusivity type |
Status |
| New chemical entity exclusivity |
Expired |
| Original drug patent protection |
Expired |
| Orphan-drug exclusivity |
Any historical period has expired |
| Pediatric exclusivity |
No material current barrier identified |
| Current market protection |
Primarily commercial, regulatory, manufacturing, and distribution-based |
The FDA approved lomustine in 1976, so statutory exclusivity associated with the original approval has long expired.[1] The practical commercial question is therefore not when the molecule loses exclusivity. It is when a competing manufacturer can obtain approval, establish reliable supply, and secure payer and pharmacy access.
What patents protect lomustine and Gleostine?
Lomustine is an old small molecule. The original active-ingredient patent estate has expired. Current competitive risk is more likely to arise from formulation, manufacturing, labeling, trade-secret, or supply-chain issues than from a valid composition patent.
U.S. patent position
The FDA Orange Book is the controlling source for patents and regulatory exclusivities listed against an approved product. For Gleostine, the commercial history has not been based on a conventional active patent wall comparable to newer oncology products.[4]
Potential IP categories include:
- capsule formulation and excipient combinations;
- manufacturing processes;
- impurity controls;
- packaging and storage systems;
- dosing regimens;
- method-of-use claims for specific brain tumors;
- product-specific trade secrets.
These categories do not automatically block an ANDA. A method-of-use patent can be addressed through a Section viii statement or labeling carve-out if the generic applicant excludes the protected indication. Manufacturing patents may be avoided through a different process or challenged in litigation.
The practical patent-strength assessment is therefore:
| IP category |
Current strategic strength |
| Composition of matter |
Very weak or expired |
| Original product patent |
Expired |
| Formulation patents |
Potentially relevant but not established as the primary barrier |
| Method-of-use patents |
Potentially relevant to selected indications |
| Manufacturing know-how |
Potentially meaningful operational barrier |
| Trade secrets |
Relevant to process consistency and scale |
| Regulatory exclusivity |
No material current barrier |
What is the FDA regulatory status and Orange Book status of lomustine?
Gleostine is an FDA-approved prescription capsule under NDA 017803. The product carries serious warnings for delayed bone-marrow suppression, secondary malignancies, and pulmonary toxicity.[1]
The regulatory structure favors generic competition because:
- the reference product is approved under an old NDA;
- the active ingredient is well characterized;
- the dosage form is an oral capsule;
- bioequivalence can generally be demonstrated through an ANDA;
- the product does not require a biosimilar application.
The main regulatory hurdle is product quality. Lomustine requires careful control of potency, content uniformity, degradation products, capsule strength, and packaging. A manufacturer also must demonstrate reliable supply for an oncology drug with limited but clinically important demand.
Which companies are challenging Gleostine with generics?
Generic competition is the central threat to the U.S. lomustine model. The likely competitive set includes manufacturers with experience in oncology capsules, controlled substances, or low-volume hospital products.
A reliable public record of all pending ANDA applicants is not generally available because FDA ANDA sponsorship information is not fully public before approval or litigation. An applicant that receives a Paragraph IV notice could trigger Hatch-Waxman litigation, but a Paragraph IV challenge is not equivalent to an approved generic or a commercial launch.
How do Paragraph IV challenges affect lomustine?
A generic applicant can file a Paragraph IV certification asserting that a listed patent is invalid, unenforceable, or not infringed. The patent holder may then file an infringement action within 45 days, potentially triggering a 30-month stay of final approval under Hatch-Waxman rules.[5]
For lomustine, the commercial importance of Paragraph IV litigation depends on whether any current Orange Book-listed patent creates a meaningful stay. Because the molecule is old and the core patent estate has expired, litigation risk is more likely to center on residual formulation or use patents.
The most probable generic-entry outcomes are:
| Scenario |
Market effect |
| No approved generic |
Gleostine retains pricing power, subject to payer pressure |
| One approved generic |
Price concessions and share loss begin quickly |
| Authorized generic |
Brand preserves channel access while reducing third-party opportunity |
| Multiple generics |
Rapid price compression and reduced brand economics |
| Generic approval with supply failure |
Limited near-term commercial disruption |
What generic launch risks exist for lomustine?
Generic entry could reduce Gleostine revenue materially because the product has a small number of prescribers, limited dosage strengths, and a concentrated dispensing channel. A single reliable generic supplier could capture a meaningful share of volume.
The principal launch risks are:
- FDA approval of an ANDA;
- a court ruling invalidating or avoiding any asserted patent;
- a settlement that permits an earlier launch;
- payer-mandated substitution;
- specialty-pharmacy formulary changes;
- hospital and integrated-delivery-network purchasing pressure;
- manufacturing scale-up by a generic supplier.
The risk is asymmetric. The generic manufacturer does not need to recreate the entire branded market. It needs only to establish supply, demonstrate bioequivalence, and obtain reimbursement. The reference company, by contrast, must defend price, access, and prescribing preference across a narrow market.
What formulation and manufacturing barriers protect lomustine?
Lomustine is commercially sensitive to manufacturing reliability. Its market is small, so generic suppliers may have limited incentive to invest in redundant production capacity. That can delay entry or produce intermittent availability even after FDA approval.
Manufacturing barriers include:
- handling of a cytotoxic active ingredient;
- low-volume production economics;
- capsule-strength accuracy;
- stability and degradation control;
- specialized packaging;
- batch-release testing;
- oncology-drug supply-chain qualification;
- inventory requirements for intermittent but urgent treatment.
These barriers are not patent exclusivity. They are execution risks. They can preserve a branded product’s commercial position for longer than the legal IP estate would suggest, but they do not prevent eventual competition by a well-capitalized manufacturer.
What competitive therapies affect lomustine demand?
Lomustine competes with other treatments used in recurrent glioblastoma and high-grade glioma. Relevant alternatives include temozolomide rechallenge, bevacizumab, tumor-treating fields in selected settings, clinical trials, reirradiation, surgery, and combination regimens such as PCV in particular disease contexts. Treatment selection depends on prior therapy, performance status, methylation status, tumor location, hematologic reserve, and institutional practice.[6]
| Competitor or alternative |
Competitive effect |
| Temozolomide |
May substitute in selected recurrent settings |
| Bevacizumab |
Competes for recurrent glioblastoma use, particularly symptom and edema control |
| PCV regimen |
Contains lomustine and is relevant in selected glioma protocols |
| Reirradiation or surgery |
Reduces drug demand in patients eligible for local treatment |
| Clinical trials |
Diverts eligible patients from standard chemotherapy |
| Supportive care |
Limits treatment in patients with poor performance status |
Lomustine retains value where oral administration, central nervous system penetration, prior physician experience, and limited alternatives support continued use. Its limitations are delayed marrow toxicity, cumulative risk, and lack of broad first-line positioning.
What litigation and settlement issues affect lomustine?
The principal legal issue is potential Hatch-Waxman litigation over any Orange Book-listed formulation or method-of-use patents. Publicly documented litigation has been less central to lomustine than to newer, heavily patented oncology products.
A settlement involving a generic applicant could establish a licensed-entry date before the expiration of any asserted patent. The financial impact would depend on whether the agreement includes:
- a fixed launch date;
- an authorized generic arrangement;
- volume or supply restrictions;
- a royalty;
- a nonexclusive license;
- restrictions on indication labeling.
No settlement should be assumed to create market exclusivity unless its terms and FDA approval status are publicly confirmed.
Does lomustine face biosimilar risk?
No. Lomustine is a chemically synthesized small molecule, not a biologic. Biosimilar regulation under the Public Health Service Act does not apply. Competition proceeds through the generic-drug pathway, principally an ANDA with a bioequivalence showing.[5]
This makes the regulatory path simpler than for biologic oncology products. It also means that once a capable generic is approved, substitution and price competition can occur more rapidly than in many biosimilar markets.
How does lomustine compare with newer oncology drugs?
Lomustine has a weaker patent estate but a lower development-risk profile than newer oncology drugs. Its commercial value is based on established use and supply access rather than patent-protected innovation.
| Factor |
Lomustine |
Newer targeted oncology drug |
| Molecular patent life |
Expired |
Often active |
| FDA pathway |
Legacy NDA; generic ANDA possible |
New drug application; complex patent estate |
| Clinical differentiation |
Limited |
Often biomarker or mechanism specific |
| Price basis |
High price in a narrow market |
High price supported by exclusivity and innovation |
| Generic risk |
Direct and potentially rapid |
Delayed by patents and regulatory exclusivity |
| Manufacturing risk |
High relative to market size |
Often complex, but supported by larger revenue |
| Revenue durability |
Vulnerable to one reliable generic |
Potentially durable until patent expiry |
What is the commercial outlook for lomustine?
The near-term outlook remains dependent on U.S. branded pricing and generic timing. Volume growth is likely to remain modest because lomustine is used mainly in recurrent or refractory disease. Revenue can remain stable while patient numbers are flat if price and reimbursement remain favorable, but that strategy increases exposure to payer intervention and generic substitution.
The most important value drivers are:
- Timing of the first approved U.S. generic.
- Whether the generic has dependable manufacturing capacity.
- Reimbursement treatment by Medicare and commercial plans.
- Continued use in recurrent glioblastoma and other brain tumors.
- The extent of price concessions by NextSource.
- Availability of competing clinical options.
- Any new formulation, indication, or distribution strategy.
The base commercial case is a mature, cash-generative niche product with limited volume growth and substantial cliff risk. The downside case is an abrupt revenue decline following generic entry. The upside case is prolonged single-source supply combined with continued use in patients who have few practical alternatives.
Key Takeaways
- Lomustine is a mature oral nitrosourea marketed in the U.S. as Gleostine.
- FDA approval dates to 1976, and original molecule and drug exclusivity have expired.
- U.S. economics were transformed by large branded price increases after NextSource acquired commercialization rights.
- Publicly available sources do not provide a complete audited standalone revenue history for Gleostine.
- Generic competition, not biosimilar competition, is the principal strategic threat.
- A single reliable generic supplier could materially reduce price and market share.
- Formulation, manufacturing, cytotoxic handling, and supply reliability may delay or limit effective generic competition.
- Lomustine demand is tied to recurrent brain tumors, selected Hodgkin lymphoma use, and specialist oncology practice.
- The product has commercial durability but limited long-term protection from legal exclusivity.
- Financial exposure is concentrated in U.S. pricing, payer access, and the timing of ANDA approval or generic launch.
FAQs
Is lomustine still available in the United States?
Yes. The U.S. branded product is Gleostine, marketed by NextSource Pharmaceuticals and supplied as 10 mg, 40 mg, and 100 mg capsules.[1]
Is Gleostine protected by a composition-of-matter patent?
No active composition-of-matter protection for the original lomustine molecule is expected to remain. The molecule and original approval are several decades old.
Can a generic manufacturer substitute lomustine automatically?
Substitution depends on FDA approval, state pharmacy law, payer policy, and whether the product is therapeutically equivalent to the reference-listed drug. FDA approval alone does not guarantee immediate pharmacy substitution.
Why is lomustine expensive despite being an old chemotherapy?
The U.S. price reflects branded commercial strategy, limited patient volume, specialty distribution, reimbursement structure, and the absence of a reliable competing product for part of the market. It does not reflect new-molecule patent protection.
Is lomustine included in the PCV chemotherapy regimen?
Yes. PCV consists of procarbazine, lomustine, and vincristine. Its use depends on tumor type, molecular characteristics, treatment history, and physician judgment.
References
- U.S. Food and Drug Administration. (2023). Gleostine (lomustine) capsules prescribing information.
- U.S. Government Accountability Office. (2018). Drug industry: Profits, research and development, and prices.
- Institute for Clinical and Economic Review. (2022). Unsupported price increases and value assessment in oncology drugs.
- U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
- U.S. Food and Drug Administration. (2024). Abbreviated new drug application process and patent certifications.
- National Comprehensive Cancer Network. (2024). NCCN clinical practice guidelines in oncology: Central nervous system cancers.
