Tositumomab and iodine i-131 tositumomab - Biologic Drug Details

Summary for tositumomab and iodine i-131 tositumomab

Tradenames:	1
High Confidence Patents:	0
Applicants:	1
BLAs:	1

Note on Biologic Patents

Matching patents to biologic drugs is far more complicated than for small-molecule drugs.

DrugPatentWatch employs three methods to identify biologic patents:

1. Brand-side disclosures in response to biosimilar applications

These patents were identified from disclosures by the brand-side company, in response to a potential biosimilar seeking to launch. They have a high certainty of blocking biosimilar entry. The expiration dates listed are not estimates — they're expiration dates as indicated by the brand-side company.

2. DrugPatentWatch analysis and brand-side disclosures

These patents were identified from searching drug labels and other general disclosures from the brand-side company. This list may exclude some of the patents which block biosimilar launch, and some of these patents listed may not actually block biosimilar launch. The expiration dates listed for these patents are estimates, based on the grant date of the patent.

3. Patents from broad patent text search

For completeness, these patents were identified by searching the patent literature for mentions of the branded or ingredient name of the drug. Some of these patents protect the original drug, whereas others may protect follow-on inventions or even inventions casually mentioning the drug. The expiration dates listed for these patents are estimates, based on the grant date of the patent.

1) High Certainty: US Patents for tositumomab and iodine i-131 tositumomab Derived from Brand-Side Litigation

No patents found based on brand-side litigation

2) High Certainty: US Patents for tositumomab and iodine i-131 tositumomab Derived from DrugPatentWatch Analysis and Company Disclosures

These patents were obtained from company disclosures

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Patent No.	Estimated Patent Expiration	Source
Glaxosmithkline Llc	BEXXAR	tositumomab and iodine i-131 tositumomab	Injection	125011		2014-01-21	DrugPatentWatch analysis and company disclosures
Glaxosmithkline Llc	BEXXAR	tositumomab and iodine i-131 tositumomab	Injection	125011		2016-04-26	DrugPatentWatch analysis and company disclosures

3) Low Certainty: US Patents for tositumomab and iodine i-131 tositumomab Derived from Patent Text Search

These patents were obtained by searching patent claims

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Patent No.	Estimated Patent Expiration	Source
Glaxosmithkline Llc	BEXXAR	tositumomab and iodine i-131 tositumomab	Injection	125011		2036-12-20	Patent claims search
Glaxosmithkline Llc	BEXXAR	tositumomab and iodine i-131 tositumomab	Injection	125011		2038-03-23	Patent claims search
Glaxosmithkline Llc	BEXXAR	tositumomab and iodine i-131 tositumomab	Injection	125011		2031-01-26	Patent claims search
Glaxosmithkline Llc	BEXXAR	tositumomab and iodine i-131 tositumomab	Injection	125011		2038-12-19	Patent claims search
Glaxosmithkline Llc	BEXXAR	tositumomab and iodine i-131 tositumomab	Injection	125011		2035-11-10	Patent claims search

Market Dynamics and Financial Trajectory for Tositumomab and Iodine I-131 Tositumomab

Last updated: July 30, 2025

Introduction

Tositumomab coupled with iodine-131 (I-131) represents a pioneering approach in targeted radiotherapy for non-Hodgkin’s lymphoma (NHL). As a first-in-class radiolabeled monoclonal antibody, its market trajectory has been influenced by clinical efficacy, regulatory developments, competition from novel therapies, and evolving treatment paradigms. This comprehensive assessment delineates the current market landscape, future growth prospects, and the associated financial trajectory for these biologic agents.

Overview of Tositumomab and Iodine I-131 Tositumomab

Tositumomab is a murine monoclonal antibody targeting the CD20 antigen expressed on B-cells, linked with iodine-131, a radioactive isotope. This conjugate offers both targeting specificity and cytotoxic radiation, providing a dual mechanism of action. Approved by the FDA in 2003 for relapsed, follicular, CD20-positive B-cell non-Hodgkin’s lymphoma, the combination was heralded for its efficacy in refractory cases.

However, the subsequent withdrawal of its approval in 2013 due to manufacturing discontinuation and the limited commercial success raises questions about its future market potential. Despite this, ongoing research and development efforts, along with potential biosimilar emergence, influence the overall market outlook.

Market Dynamics

Regulatory Environment and Clinical Adoption

Initially, I-131 Tositumomab garnered FDA approval based on clinical trials demonstrating substantial response rates in relapsed or refractory follicular lymphoma. The subsequent withdrawal was mainly tied to manufacturing challenges and safety concerns, such as delayed myelosuppression. The regulatory environment remains critical, especially with evolving oncology treatment standards emphasizing personalized, targeted therapies.

Regulatory bodies now favor monoclonal antibody-based therapies with proven safety profiles. The discontinuation of I-131 Tositumomab highlights a significant hurdle: manufacturing complexity and supply chain stability. The potential reintroduction would necessitate substantial regulatory approvals, safety validations, and manufacturing reinvestment.

Competitive Landscape

The era of Tositumomab is increasingly overshadowed by newer therapies, including CD19/CD20-targeted CAR T-cell therapies (e.g., Kymriah, Yescarta). These therapies deliver high response rates for relapsed NHL but at elevated costs and with significant toxicity profiles.

Additionally, newer monoclonal antibodies such as rituximab, obinutuzumab, and obinutuzumab biosimilars dominate the market, offering similar efficacy with improved convenience and safety. Radioimmunotherapies like Zevalin (ibritumomab tiuxetan), approved in 2002, have maintained some clinical relevance, but their use is limited by logistical challenges and regulatory restrictions, similar to I-131 Tositumomab.

Market Drivers and Barriers

• Drivers:

  • Unmet needs in refractory NHL populations.
  • Potential for improved targeting with next-generation radiolabeled antibodies.
  • Advances in nuclear medicine facilitating safer delivery.

• Barriers:

  • Manufacturing complexities and costs.
  • Competition from highly effective CAR T-cell therapies.
  • Limited commercial availability and clinical familiarity.
  • Regulatory hurdles and safety concerns.

Emerging Opportunities

Research into next-generation radioimmunoagents and combination strategies with immunomodulators may revitalize interest in radiolabeled antibodies. Furthermore, partnerships with nuclear medicine companies could streamline manufacturing and distribution, potentially restoring market viability.

Financial Trajectory

Historical Revenue and Investment Outlook

Initially, I-131 Tositumomab generated moderate revenues, primarily serving niche indications within NHL treatment. Its commercial viability was constrained by manufacturing difficulties and competition from other monoclonal antibodies. The withdrawal of approval curtailed revenue streams, leading to diminished institutional and manufacturer investment.

Pharmaceutical companies have largely deprioritized investment, leading to an estimated zero revenue trajectory in the current market context. Nonetheless, the asset value persists as a potential backbone for future radiolabeled antibody therapies.

Future Revenue Potential

Any re-entry into the market hinges on manufacturing reinstatement, regulatory approval, and clinician acceptance. A revamped version targeting specific subpopulations or combination regimens could unlock incremental revenues estimated at $50 million to $200 million annually, contingent on clinical success and regulatory pathways.

Cost Structure and Investment Considerations

• Development costs for reformulation, clinical trials, and regulatory submissions could range from $100 million to $300 million, depending on scope.
• Manufacturing costs are significant due to radioisotope handling and compliance with nuclear regulatory standards.
• Market size estimation for relapsed NHL patients eligible for radiolabeling is approximately 10,000 to 20,000 globally, with potential to expand into broader B-cell malignancies.

Market Growth and Investment Trends

The radiopharmaceutical sector is witnessing accelerated investment, driven by precision medicine and theranostics. Companies like Novartis (with Lutathera) exemplify lucrative opportunities in nuclear medicine, suggesting a favorable environment for reintroduced radiolabeled antibodies like Tositumomab.

Furthermore, emerging collaborations between nuclear medicine companies and biotech firms could lower development costs and accelerate time-to-market, ultimately improving financial prospects.

Conclusion

The market dynamics for I-131 Tositumomab are shaped by regulatory challenges, competitive therapies, and technological innovations in oncology. While current commercial activity is limited, strategic repositioning, technological advances in manufacturing, and integration with modern oncology pipelines could offer revivification opportunities.

Financially, the asset’s future hinges on successful manufacturing revival and clinical validation. The potential for niche application in refractory B-cell malignancies remains, with estimated revenue opportunities in the low hundreds of millions annually, contingent upon successful repositioning.

Key Takeaways

• Regulatory and Manufacturing Challenges: Restoring I-131 Tositumomab’s market presence requires overcoming complex manufacturing hurdles and securing regulatory clearance.
• Competitive Landscape: Advances in CAR T-cell therapies and monoclonal antibodies diminish the relative market share of radiolabeled antibodies, necessitating niche specialization or combination approaches.
• Emerging Opportunities: Innovations in theranostics and nuclear medicine partnerships could rejuvenate the asset, especially with next-generation radioimmunoconjugates.
• Investment Outlook: While historically limited, strategic repositioning offers a moderate growth trajectory, especially given the global oncology market’s increasing focus on precision treatments.
• Industry Trends: The broader shift toward personalized, targeted radiation therapies supports potential future growth avenues for Tositumomab-based agents.

FAQs

1. What are the primary challenges facing the reintroduction of I-131 Tositumomab?
   Regulatory approval complexities, manufacturing discontinuation, safety concerns, and competition from newer therapies are primary hurdles.

2. How does Tositumomab compare with other radioimmunotherapies like Zevalin?
   Both target CD20-positive B-cells but differ in isotope, efficacy, and logistical considerations. Zevalin remains commercially available, whereas Tositumomab’s market is limited due to manufacturing issues.

3. Could combination therapies enhance the marketability of I-131 Tositumomab?
   Yes, combining with immunomodulators or checkpoint inhibitors might improve efficacy and broaden indications, potentially revitalizing interest.

4. What is the potential global market size for radioimmunotherapy in NHL?
   Approximately 10,000 to 20,000 eligible patients worldwide annually, with growth avenues in expanding indications and emerging markets.

5. Are there ongoing clinical trials or developments related to Tositumomab?
   Currently, no significant large-scale trials focus on Tositumomab, but research into next-generation radioimmunoconjugates persists in academia and niche biotech sectors.

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References

1. U.S. Food and Drug Administration. (2013). Withdrawal of Approval for I-131 Tositumomab.
2. Marcus, R., et al. (2008). NHL treatments and radioimmunotherapy. Journal of Clinical Oncology.
3. European Medicines Agency. (2002). Zevalin (ibritumomab tiuxetan) approval details.
4. Verbrugge, I., et al. (2018). Emerging role of radiolabeled antibodies in cancer. Nature Reviews Drug Discovery.
5. Novartis AG. (2021). Theranostics and nuclear medicine growth strategies.