List of Excipients in Branded Drug LARTRUVO

Last updated: August 8, 2026

LARTRUVO (olaratumab) is a withdrawn oncology biologic whose commercial value is limited as a marketed product. Its formulation used a conventional antibody excipient system: histidine buffer, sodium chloride, mannitol, polysorbate 20, and water for injection. The strongest commercial opportunities are therefore formulation-platform licensing, excipient substitution research, analytical comparability services, and salvage of manufacturing knowledge, not direct generic or biosimilar entry.

LARTRUVO Excipient Strategy, Patent Position, and Commercial Opportunities

What is LARTRUVO and why does its excipient strategy matter?

LARTRUVO is olaratumab, a recombinant human IgG1 monoclonal antibody targeting platelet-derived growth factor receptor alpha, or PDGFR-alpha. Eli Lilly developed it with doxorubicin for advanced or metastatic soft-tissue sarcoma.

The FDA granted accelerated approval in October 2016 based on a phase 2 study. A required confirmatory trial, ANNOUNCE, failed to confirm the clinical benefit. Lilly stopped enrollment and new patient treatment in January 2019, and the FDA formally withdrew approval in January 2020. The European Commission withdrew the marketing authorization in April 2019 after an earlier suspension.[1-4]

LARTRUVO's excipient composition is commercially relevant because it illustrates a standard liquid monoclonal-antibody formulation that balances:

• pH control
• ionic strength
• protein aggregation risk
• freeze-thaw and agitation stability
• subcutaneous or intravenous administration constraints
• container-closure compatibility
• manufacturing scale-up

Because LARTRUVO is no longer an approved commercial product, the excipient system has greater value as a technical reference than as a direct product-entry target.

What excipients are used in the LARTRUVO formulation?

The FDA prescribing information identifies the following inactive ingredients in LARTRUVO injection:[1]

Excipient	Primary formulation role	Commercial relevance
L-histidine	Buffer component	Controls formulation pH and supports antibody stability
L-histidine hydrochloride monohydrate	Buffer salt	Adjusts buffer capacity and ionic conditions
Sodium chloride	Tonicity and ionic-strength modifier	Supports infusion tolerability and protein stability
Mannitol	Bulking agent and stabilizer	Contributes to tonicity and may reduce physical stress during processing
Polysorbate 20	Surfactant	Limits adsorption and aggregation at air-liquid and container interfaces
Water for injection	Solvent	Parenteral vehicle

The product was supplied as a sterile, preservative-free solution at 10 mg/mL in single-dose vials. The labeled presentations were 190 mg in 19 mL and 500 mg in 50 mL.[1]

The formulation does not use a novel delivery technology, depot system, lipid nanoparticle, antibody-drug conjugate linker, or device-integrated excipient platform. Its development profile is consistent with an intravenous monoclonal-antibody formulation using a low-complexity excipient set.

How does each LARTRUVO excipient affect formulation performance?

Histidine buffer system

Histidine and histidine hydrochloride provide the buffering system. Histidine is frequently used in antibody formulations because it can provide useful buffering capacity in the mildly acidic to near-neutral pH range and is generally compatible with parenteral products.

For an olaratumab-type antibody, the key development questions would include:

• pH-dependent aggregation
• charge-variant formation
• deamidation
• oxidation
• viscosity
• freeze-thaw sensitivity
• interaction with polysorbate 20

A reformulator would normally screen histidine against acetate, succinate, phosphate, citrate, and other buffers. The objective would be to identify whether a different buffer improves long-term stability or reduces degradation without changing the antibody's higher-order structure.

Sodium chloride

Sodium chloride adjusts tonicity and ionic strength. Its level must be balanced against protein stability. Higher ionic strength can affect colloidal stability, viscosity, charge interactions, and aggregation behavior.

For intravenous dosing, isotonicity and infusion tolerability are important. Sodium chloride also affects analytical comparability because changes in ionic strength can alter size-exclusion, ion-exchange, capillary electrophoresis, and particle measurements.

Mannitol

Mannitol can act as a tonicity contributor and bulking agent. In a liquid antibody formulation, it may also influence viscosity and protein-excipient interactions. In a lyophilized version, mannitol could provide cake structure, although crystallization behavior would need to be controlled.

A commercial reformulation program could compare mannitol with sucrose, trehalose, sorbitol, or other stabilizing excipients. Such substitutions may create a new formulation patent position if they produce a measurable improvement in stability, concentration, administration, or storage.

Polysorbate 20

Polysorbate 20 protects the antibody against interfacial stress caused by filling, transport, shaking, and infusion. It can reduce adsorption to glass, elastomeric components, and infusion equipment.

Polysorbate 20 also creates a known development risk. It can degrade through hydrolysis and oxidation, generating subvisible particles, free fatty acids, and peroxide-related stress. A reformulator would evaluate:

• polysorbate concentration
• degradation rate
• peroxide burden
• particle formation
• compatibility with vial and stopper materials
• interaction with stainless steel and single-use manufacturing components

Polysorbate 80, poloxamers, and newer low-peroxide surfactant systems could be evaluated as alternatives. A switch would require a full comparability program because surfactant identity can affect aggregation, particles, potency, and immunogenicity-related quality attributes.

What formulation patents protect LARTRUVO?

Publicly available FDA labeling confirms the composition and presentations but does not, by itself, establish a complete patent estate. LARTRUVO is a biologic licensed under BLA 125553 rather than a conventional small-molecule product with an FDA Orange Book listing.[1,5]

The relevant intellectual-property categories are likely to include:

IP category	Relevance to LARTRUVO	Entry significance
Antibody composition claims	Cover olaratumab molecules, sequences, or binding characteristics	Potentially material during any future development
Cell-line and production claims	Cover recombinant expression or manufacturing methods	May create process-development barriers
Formulation claims	Could cover antibody concentration, pH, buffer, surfactant, stabilizer, or storage conditions	Relevant to follow-on formulation products
Method-of-use claims	Could cover PDGFR-alpha-positive cancers or combination treatment with doxorubicin	Clinical-label and patent-risk relevance
Container-closure claims	Could cover vial, stopper, filling, or stability configurations	Usually narrower commercial scope
Analytical or manufacturing know-how	Includes purification, viral clearance, aggregation control, and release testing	Often protected as trade secrets rather than patents

No conclusion about active patent enforceability should be drawn from the product label alone. Biologic patent review requires a search of USPTO, WIPO, and jurisdiction-specific records, followed by claim-status and family analysis.

What is the Orange Book and Purple Book status of LARTRUVO?

LARTRUVO is not an Orange Book small-molecule product. Biologic exclusivity and biosimilar reference-product information are handled through the Purple Book framework.[5]

The key regulatory dates are:

Event	Date
FDA accelerated approval	October 19, 2016
ANNOUNCE trial results failed to confirm benefit	January 2019
Lilly stopped new treatment and enrollment	January 2019
European authorization withdrawn	April 2019
FDA approval withdrawal	January 2020

The FDA withdrawal removed the product's U.S. marketing authorization. That action materially reduces the commercial relevance of Paragraph IV litigation, which is associated primarily with ANDA filings for small-molecule drugs. A biosimilar applicant would face a more complex commercial problem: a withdrawn reference product, limited current demand, and no established treatment position.

When did LARTRUVO lose exclusivity and commercial protection?

LARTRUVO lost practical commercial exclusivity when Lilly discontinued new treatment and the regulatory authorizations were withdrawn. This is different from a standard patent-expiration event.

The product's commercial risk profile is therefore defined by regulatory withdrawal rather than by a predictable generic-launch date. Even if patent or regulatory exclusivity had remained in some jurisdiction, the lack of an active approved indication would sharply reduce the value of an immediate follow-on product.

The 12-year U.S. reference-product exclusivity period for a biologic is not the same as market availability. For LARTRUVO, the product's clinical and regulatory discontinuation occurred before the end of that period. A follow-on developer would still need to assess reference-product eligibility, FDA requirements, product quality, and the commercial rationale for development.[5]

Are there Paragraph IV challenges or biosimilar competitors to LARTRUVO?

No material commercial Paragraph IV challenge is associated with LARTRUVO because it is a biologic, not an ANDA-listed small molecule.

No established biosimilar competitor has achieved a meaningful U.S. commercial position for olaratumab. The main barriers are:

1. The reference product was withdrawn.
2. The clinical indication lost support after ANNOUNCE.
3. A biosimilar would need extensive analytical and clinical justification.
4. Sarcoma is a specialized market with limited addressable volume.
5. Physicians and payers would have little reason to substitute a follow-on product for a withdrawn therapy.

A developer could theoretically pursue a novel olaratumab program or another PDGFR-alpha antibody, but that would be a new biologic development strategy rather than ordinary biosimilar substitution.

What commercial opportunities exist for LARTRUVO excipients?

Reformulation platform licensing

The excipient system can support a platform program for liquid monoclonal antibodies. Opportunities include:

• low-peroxide polysorbate systems
• surfactant replacement
• high-concentration antibody formulations
• reduced-volume intravenous dosing
• room-temperature stability
• freeze-thaw protection
• compatibility with prefilled syringes or cartridges
• conversion from liquid to lyophilized dosage forms

The commercial asset would be the formulation technology, not LARTRUVO itself.

Excipient supplier partnerships

Suppliers could position pharmaceutical-grade materials for antibody manufacturers by offering:

• controlled peroxide specifications
• low-endotoxin mannitol
• high-purity histidine buffers
• compendial-grade polysorbate 20
• oxidation-resistant surfactant systems
• extractables and leachables packages
• stability data across biologic platforms

Polysorbate degradation is the most actionable formulation opportunity in the LARTRUVO composition. A supplier that reduces particle formation or extends shelf life could create value across multiple antibody products.

Analytical and comparability services

LARTRUVO-related formulation knowledge can support contract development organizations performing:

• forced-degradation studies
• subvisible-particle testing
• surfactant degradation analysis
• size-exclusion chromatography
• ion-exchange profiling
• peptide mapping
• glycan analysis
• container-closure compatibility
• shipping and agitation studies

These services are relevant to biosimilars, biobetters, and new antibodies even when the original reference product is no longer marketed.

Salvage of manufacturing knowledge

Lilly or a licensee could potentially use process knowledge from olaratumab development in other PDGFR-alpha or oncology antibody programs. Relevant assets may include cell culture, purification, viral clearance, formulation, filling, and release-testing methods.

Trade-secret value depends on whether the information remains confidential and transferable. Publicly disclosed formulation ingredients alone provide limited defensible differentiation.

How strong is the LARTRUVO patent estate?

The commercial strength of the estate is weak for direct product exploitation because the product is withdrawn and clinical benefit was not confirmed. Patent strength should be separated into three categories:

Category	Assessment
Product claims	Potentially significant if valid claims cover the antibody sequence or binding activity, but practical value is reduced by withdrawal
Formulation claims	Potentially useful for specific concentration, pH, excipient, or stability combinations; unlikely to create broad exclusivity without unexpected results
Method-of-use claims	Commercial value is substantially weakened by the negative confirmatory trial and withdrawal

A formulation patent based only on replacing one conventional excipient with another would face vulnerability to obviousness and routine-optimization arguments. Stronger protection would require data showing an unexpected improvement, such as materially lower aggregation, improved stability, reduced particles, or a clinically meaningful administration advantage.

What generic launch risks exist for LARTRUVO?

A conventional generic launch is not the central risk. The practical risks are:

• unauthorized compounding or off-label use after withdrawal
• a new antibody using a similar target or treatment concept
• repurposing of formulation know-how in another biologic
• patent claims that cover manufacturing or antibody sequences
• use of the same excipient strategy in a competing oncology antibody

For investors and licensing teams, revenue exposure is close to zero from current LARTRUVO sales because the product is withdrawn. Historical revenue was limited relative to major oncology biologics, and the failed ANNOUNCE trial eliminated the principal expansion case.[2,3]

How does LARTRUVO compare with other antibody formulation strategies?

Attribute	LARTRUVO	Modern high-concentration antibody program
Route	Intravenous	Often subcutaneous or intravenous
Concentration	10 mg/mL	Frequently 100 mg/mL or higher
Buffer	Histidine system	Histidine, acetate, citrate, phosphate, or proprietary systems
Surfactant	Polysorbate 20	Polysorbate 20, polysorbate 80, poloxamer, or alternatives
Stabilizer	Mannitol	Sucrose, trehalose, sorbitol, mannitol, amino acids
Commercial focus	Infusion product	Reduced administration time, device compatibility, and home use
IP opportunity	Narrow formulation and process claims	High-concentration, device, excipient, and administration claims

LARTRUVO's formulation is therefore a useful baseline but not a differentiated commercial platform by itself.

Key Takeaways

• LARTRUVO is withdrawn in the United States and Europe after the ANNOUNCE confirmatory trial failed.
• Its formulation contains histidine, histidine hydrochloride monohydrate, sodium chloride, mannitol, polysorbate 20, and water for injection.
• The product is a biologic under BLA 125553 and is not an Orange Book small-molecule product.
• Paragraph IV litigation is not the principal entry framework.
• No meaningful commercial biosimilar market has developed for olaratumab.
• The strongest opportunities involve excipient technology, polysorbate stabilization, formulation licensing, analytical services, and manufacturing know-how.
• A new formulation patent would need evidence of an unexpected stability, usability, or manufacturing benefit.
• Direct LARTRUVO revenue exposure is negligible after regulatory withdrawal.

FAQs About LARTRUVO Excipients and Commercialization

Is polysorbate 20 in the LARTRUVO injection?

Yes. Polysorbate 20 is used as a surfactant to reduce antibody adsorption and aggregation during manufacturing, filling, transport, and infusion.

Could LARTRUVO be reformulated as a subcutaneous injection?

Technically, a subcutaneous reformulation could be evaluated, but it would require a new development program addressing concentration, viscosity, injection volume, local tolerability, immunogenicity, device compatibility, and clinical benefit.

Is mannitol in LARTRUVO a novel excipient?

No. Mannitol is a widely used pharmaceutical excipient. Its use in LARTRUVO does not, by itself, create strong formulation exclusivity.

Can a company launch an olaratumab biosimilar after withdrawal?

A company could assess a biosimilar or new biologic pathway, but the withdrawn reference product and failed confirmatory trial create substantial regulatory and commercial obstacles.

What is the most attractive excipient opportunity associated with LARTRUVO?

The most attractive opportunity is development of a more stable surfactant system, particularly one that reduces polysorbate oxidation, free-fatty-acid generation, and subvisible particles in liquid monoclonal-antibody products.

References

1. U.S. Food and Drug Administration. (2016). LARTRUVO (olaratumab) injection, prescribing information. Eli Lilly and Company.

2. Tap, W. D., Jones, R. L., Van Tine, B. A., Chmielowski, B., Elias, A. D., Adkins, D., ... Schöffski, P. (2019). Olaratumab and doxorubicin versus doxorubicin alone for treatment of advanced or metastatic soft-tissue sarcoma: The ANNOUNCE phase 3 randomized clinical trial. JAMA, 321(13), 1266-1276.

3. Eli Lilly and Company. (2019, January 18). Lilly provides update on olaratumab in advanced soft tissue sarcoma. Company release.

4. European Medicines Agency. (2019). Lartruvo: EPAR - product information and authorization status. European Medicines Agency.

5. U.S. Food and Drug Administration. (2024). Purple Book: Database of licensed biological products. U.S. Food and Drug Administration.