CYTALUX Drug Patent Profile

When do Cytalux patents expire, and what generic alternatives are available?

Cytalux is a drug marketed by On Target Labs and is included in one NDA. There are six patents protecting this drug.

This drug has thirty-five patent family members in twelve countries.

The generic ingredient in CYTALUX is pafolacianine sodium. One supplier is listed for this compound. Additional details are available on the pafolacianine sodium profile page.

DrugPatentWatch^® Generic Entry Outlook for Cytalux

Cytalux was eligible for patent challenges on November 29, 2025.

By analyzing the patents and regulatory protections it appears that the earliest date for generic entry will be August 26, 2033. This may change due to patent challenges or generic licensing.

Indicators of Generic Entry

Summary for CYTALUX

International Patents:	35
US Patents:	6
Applicants:	1
NDAs:	1
Finished Product Suppliers / Packagers:	1
Clinical Trials:	6
What excipients (inactive ingredients) are in CYTALUX?	CYTALUX excipients list
DailyMed Link:	CYTALUX at DailyMed

DrugPatentWatch^® Estimated Loss of Exclusivity (LOE) Date for CYTALUX

NDA:

214907

Dosage:

SOLUTION;INTRAVENOUS

^*The generic entry opportunity date is the latter of the last compound-claiming patent and the last regulatory exclusivity protection. Many factors can influence early or later generic entry. This date is provided as a rough estimate of generic entry potential and should not be used as an independent source.

Recent Clinical Trials for CYTALUX

Identify potential brand extensions & 505(b)(2) entrants

Sponsor	Phase
Abramson Cancer Center at Penn Medicine	EARLY_PHASE1
On Target Laboratories, LLC	PHASE4
Cedars-Sinai Medical Center	PHASE4

See all CYTALUX clinical trials

Pharmacology for CYTALUX

Drug Class	Optical Imaging Agent
Mechanism of Action	Fluorescence Contrast Activity

US Patents and Regulatory Information for CYTALUX

CYTALUX is protected by six US patents and two FDA Regulatory Exclusivities.

Generics may enter earlier, or later, based on new patent filings, patent extensions, patent invalidation, early generic licensing, generic entry preferences, and other factors.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
On Target Labs	CYTALUX	pafolacianine sodium	SOLUTION;INTRAVENOUS	214907-001	Nov 29, 2021		RX	Yes	Yes			Y	Y
On Target Labs	CYTALUX	pafolacianine sodium	SOLUTION;INTRAVENOUS	214907-001	Nov 29, 2021		RX	Yes	Yes
On Target Labs	CYTALUX	pafolacianine sodium	SOLUTION;INTRAVENOUS	214907-001	Nov 29, 2021		RX	Yes	Yes			Y	Y
On Target Labs	CYTALUX	pafolacianine sodium	SOLUTION;INTRAVENOUS	214907-001	Nov 29, 2021		RX	Yes	Yes

International Patents for CYTALUX

When does loss-of-exclusivity occur for CYTALUX?

Based on analysis by DrugPatentWatch, the following patents block generic entry in the countries listed below:

Australia

Brazil

Canada

China

Eurasian Patent Organization

European Patent Office

Hong Kong

Israel

Japan

Mexico

Spain

Generics may enter earlier, or later, based on new patent filings, patent extensions, patent invalidation, early generic licensing, generic entry preferences, and other factors.

See the table below for additional patents covering CYTALUX around the world.

Country	Patent Number	Title	Estimated Expiration
Mexico	2015013223
Canada	2903994
Brazil	112015022810	síntese e composição de grupos de ligação de aminoácidos conjugados a compostos utilizados para a criação de imagens específicas de tumores
Israel	240509	Fluorescence imaging of inflammatory diseases

Cytalux: Market Dynamics and Financial Trajectory

Last updated: February 19, 2026

What is Cytalux and Its Therapeutic Application?

Cytalux, known chemically as mirvetuximab soravtansine, is a receptor-targeted antibody-drug conjugate (ADC) developed by ImmunoGen Inc. It is designed to treat folate receptor alpha (FRα)-positive epithelial ovarian, fallopian tube, and primary peritoneal cancers. Cytalux works by delivering a potent chemotherapy agent, DM4, directly to cancer cells that express FRα. The antibody component of the ADC binds to FRα on cancer cells, facilitating the internalization of the conjugate and the release of the cytotoxic payload within the tumor cell, thereby inducing cell death. This targeted approach aims to minimize systemic toxicity compared to traditional chemotherapy.

What is the Current Regulatory Status and Market Authorization for Cytalux?

Cytalux received accelerated approval from the U.S. Food and Drug Administration (FDA) on November 22, 2022, for the treatment of adult patients with FRα-positive, platinum-resistant epithelial ovarian cancer, fallopian tube cancer, or primary peritoneal cancer, who have received one to three prior systemic treatment regimens. The approval was based on the MIRASOL study’s objective response rate (ORR) and duration of response (DoR).

The FDA's accelerated approval pathway allows for earlier marketing approval of drugs that treat serious conditions and fulfill an unmet medical need, based on a surrogate endpoint that is reasonably likely to predict clinical benefit. Continued approval for Cytalux is contingent upon the verification of clinical benefit in a confirmatory trial. ImmunoGen is conducting the Phase 3 PADRE trial, designed to confirm the clinical benefit of mirvetuximab soravtansine.

What is the Competitive Landscape for FRα-Targeted Ovarian Cancer Therapies?

The ovarian cancer market, particularly for platinum-resistant disease and FRα-positive subtypes, is becoming increasingly competitive. Cytalux faces competition from other treatments targeting similar patient populations, as well as emerging therapies in development.

Key competitors and their current status include:

• Plinabalin (Mirvetuximab Soravtansine) - Developed by ImmunoGen: Currently approved for platinum-resistant FRα-positive ovarian cancer. Its long-term success hinges on the confirmatory PADRE trial.
• Dostarlimab (Jemperli) - Developed by GSK: While not directly targeting FRα, dostarlimab is an anti-PD-1 antibody approved for certain endometrial cancers with specific molecular characteristics, and it is being investigated in ovarian cancer, particularly in combination therapies. Its mechanism of action is immune-mediated rather than direct tumor cell targeting.
• Chemotherapy Regimens: Traditional platinum-based chemotherapy (e.g., carboplatin, cisplatin), taxanes (paclitaxel, docetaxel), liposomal doxorubicin, and gemcitabine remain standard-of-care options for various stages of ovarian cancer and may be used sequentially or in combination.
• PARP Inhibitors: For patients with specific genetic mutations (e.g., BRCA mutations), PARP inhibitors like olaparib, niraparib, and rucaparib are established treatments for maintenance therapy and in certain treatment settings. These target DNA repair pathways.
• Other ADCs in Development: Several other ADCs are in various stages of clinical development targeting ovarian cancer, some of which may also target FRα or other tumor-associated antigens. These represent future competitive threats.
• Bevacizumab (Avastin) - Developed by Roche: A VEGF inhibitor that has demonstrated efficacy in combination with chemotherapy for ovarian cancer, particularly in patients with high-risk disease. It is approved in combination with chemotherapy and as maintenance therapy.

The competitive advantage of Cytalux lies in its direct FRα targeting and the ADC mechanism, aiming for improved efficacy and potentially reduced toxicity compared to systemic chemotherapy. However, the ongoing confirmatory trial is crucial for solidifying its market position against established and emerging therapies.

What are the Key Clinical Trial Data Supporting Cytalux's Efficacy?

The accelerated approval of Cytalux was based on data from the MIRASOL (GOG 3033/ENGOT-OV50) Phase 3 trial.

Key efficacy findings from MIRASOL:

• Objective Response Rate (ORR): Cytalux demonstrated an ORR of 32% in patients with FRα-positive, platinum-resistant ovarian cancer, compared to 4% for chemotherapy (investigator’s choice). This met the primary endpoint of the study.
• Duration of Response (DoR): The median DoR was 6.9 months for Cytalux compared to 5.6 months for chemotherapy.
• Disease Control Rate (DCR): The DCR was 74% for Cytalux versus 52% for chemotherapy.
• Progression-Free Survival (PFS): While not the primary endpoint for accelerated approval, median PFS was 5.5 months for Cytalux and 3.3 months for chemotherapy.
• Overall Survival (OS): Median OS was 16.4 months for Cytalux compared to 12.7 months for chemotherapy.

These results indicated a statistically significant and clinically meaningful improvement in response rates and demonstrated a trend towards improved survival outcomes for Cytalux.

What is the Financial Trajectory and Market Potential for Cytalux?

The financial trajectory of Cytalux is directly linked to its market penetration, pricing strategy, and the eventual outcome of its confirmatory trial. ImmunoGen has projected significant revenue potential for mirvetuximab soravtansine.

Key financial considerations:

• Pricing: ImmunoGen has announced a wholesale acquisition cost (WAC) for Cytalux of approximately $5,000 per vial. The average patient is estimated to receive 25 vials per treatment cycle, resulting in an estimated cost of $125,000 per cycle. Given multiple cycles are typical, annual treatment costs per patient are substantial.
• Market Size: The target patient population for FRα-positive, platinum-resistant ovarian cancer is significant. ImmunoGen estimates that approximately 30-40% of ovarian cancer patients have tumors that express FRα at clinically relevant levels, translating to a substantial addressable market in the U.S. and globally.
• Revenue Projections: Following the accelerated approval, analysts have provided revenue forecasts for mirvetuximab soravtansine. For example, prior to full approval, some projections indicated peak sales potential in the range of $500 million to over $1 billion annually, contingent on confirmatory trial success and broader market adoption.
• Commercialization Strategy: ImmunoGen's commercialization efforts are focused on building a dedicated sales force and establishing partnerships to ensure broad access and physician education.
• Impact of Confirmatory Trial: The successful completion and positive results of the PADRE trial are critical for converting the accelerated approval to full approval, which would solidify its market access and long-term financial viability. Failure to meet the primary endpoint of PADRE could significantly impact revenue projections and market sentiment.
• Acquisition by AbbVie: In November 2023, AbbVie announced its intention to acquire ImmunoGen for approximately $10 billion in cash. This acquisition significantly changes the financial outlook for Cytalux, as it now becomes part of a larger pharmaceutical company with established commercial infrastructure and R&D capabilities. AbbVie's strategic integration of Cytalux is expected to accelerate its market penetration and global expansion. This deal highlights the perceived significant market potential of Cytalux by a major pharmaceutical player.

The financial future of Cytalux is thus intrinsically tied to its clinical validation and successful integration into AbbVie’s portfolio.

What are the Safety Profile and Tolerability Considerations for Cytalux?

The safety profile of Cytalux is a critical factor influencing its clinical use and market acceptance. Adverse events are managed through dose modifications, interruptions, or discontinuations.

Common adverse events (AEs) observed in clinical trials include:

• Ocular Toxicities: Blurred vision, dry eye, and retinal pigment epithelial detachment are notable ocular side effects. These are managed with proactive eye care and monitoring.
• Gastrointestinal Events: Nausea, vomiting, diarrhea, and constipation are common.
• Hematologic Events: Neutropenia, thrombocytopenia, and anemia are also observed, requiring regular blood count monitoring.
• Fatigue and Asthenia: Patients frequently report generalized weakness and tiredness.
• Peripheral Neuropathy: This is a class effect for many chemotherapy agents and ADCs.

Serious adverse events (SAEs) requiring dose adjustments or discontinuation have included ocular toxicities, neutropenia, and peripheral neuropathy. The benefit-risk profile, as assessed by the FDA for accelerated approval, indicates that Cytalux offers a favorable balance for patients with limited treatment options. Continued monitoring and data collection from the confirmatory trial will further refine the understanding of its long-term safety.

What are the Key Takeaways for Cytalux?

Cytalux (mirvetuximab soravtansine) has achieved accelerated FDA approval for FRα-positive, platinum-resistant ovarian cancer, based on significant improvements in ORR and DoR demonstrated in the MIRASOL trial. Its financial trajectory is strongly positive, evidenced by substantial revenue projections and the pending $10 billion acquisition of ImmunoGen by AbbVie, indicating high market potential. The competitive landscape is evolving, with other targeted therapies and ADCs in development, making the successful completion of its confirmatory PADRE trial crucial for long-term market positioning. Cytalux's safety profile, while manageable, includes notable ocular and gastrointestinal toxicities that require careful patient monitoring and management.

Frequently Asked Questions About Cytalux

1. What specific molecular biomarker is required for Cytalux treatment? Patients must have tumors that are positive for folate receptor alpha (FRα) to be eligible for Cytalux treatment. This is determined through companion diagnostic testing.

2. What is the primary indication for Cytalux's accelerated approval? Cytalux is indicated for adult patients with FRα-positive, platinum-resistant epithelial ovarian cancer, fallopian tube cancer, or primary peritoneal cancer who have received one to three prior systemic treatment regimens.

3. What is the mechanism of action for Cytalux? Cytalux is an antibody-drug conjugate that targets FRα on cancer cells and delivers a cytotoxic agent (DM4) directly into the tumor cell to induce cell death.

4. What is the significance of the PADRE trial for Cytalux? The PADRE trial is a Phase 3 confirmatory study designed to verify the clinical benefit of mirvetuximab soravtansine. Successful completion is required to convert the current accelerated approval to full FDA approval.

5. Which major pharmaceutical company is acquiring ImmunoGen, the developer of Cytalux? AbbVie announced its intention to acquire ImmunoGen in November 2023 for approximately $10 billion.

Citations

[1] ImmunoGen Inc. (n.d.). Cytalux® (mirvetuximab soravtansine-gynx). Retrieved from https://www.immunogen.com/pipeline/cytalux/ [2] U.S. Food & Drug Administration. (2022, November 22). FDA approves mirvetuximab soravtansine-gynx for FRα-positive, platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer. FDA News Release. [3] ImmunoGen Inc. (2023, October 12). ImmunoGen Announces Positive Topline Results from the Phase 3 MIRASOL Study of E’s Leading FRα-Targeting ADC, MIRVETUXIMAB SORAVTANINE, Demonstrating Superiority Over Chemotherapy in Women With Relapsed Ovarian Cancer. Press Release. [4] AbbVie. (2023, November 30). AbbVie Announces Definitive Agreement to Acquire ImmunoGen. Press Release.