Litigation Details for CATALYST PHARMACEUTICALS, INC. v. JACOBUS PHARMACEUTICALS COMPANY, INC. (D.N.J. 2020)

CATALYST PHARMACEUTICALS, INC. v. JACOBUS PHARMACEUTICALS COMPANY, INC. (D.N.J. 2020)

Docket		Date Filed	2020-10-16
Court	District Court, D. New Jersey	Date Terminated	2022-07-13
Cause	35:271 Patent Infringement	Assigned To	Michael Andre Shipp
Jury Demand	Both	Referred To	Douglas Arpert
Parties	JACOBUS PHARMACEUTICALS COMPANY, INC.
Patents	10,793,893; 11,060,128
Attorneys	DENNIES VARUGHESE
Firms	Sterne Kessler Goldstein and Fox
Link to Docket	External link to docket

Details for CATALYST PHARMACEUTICALS, INC. v. JACOBUS PHARMACEUTICALS COMPANY, INC. (D.N.J. 2020)

Date Filed	Document No.	Description	Snippet	Link To Document
2020-10-16				External link to document

Catalyst Pharmaceuticals v. Jacobus Pharmaceuticals Patent Litigation: Firdapse, Ruzurgi, and Amifampridine Exclusivity

Last updated: August 11, 2026

Catalyst Pharmaceuticals’ lawsuit against Jacobus Pharmaceuticals concerned whether Jacobus’ Ruzurgi (amifampridine phosphate) infringed Catalyst’s patent covering treatment of Lambert-Eaton myasthenic syndrome (LEMS). The case was filed in the U.S. District Court for the District of New Jersey under No. 3:20-cv-14590.

The dispute was separate from Catalyst’s challenge to the FDA’s approval of Ruzurgi. It was also not a conventional Paragraph IV ANDA case because Ruzurgi was approved under an NDA rather than as a generic version of Firdapse.

What patents did Catalyst assert against Jacobus?

Catalyst asserted U.S. Patent No. 9,192,644, titled "Methods of Treating Lambert-Eaton Myasthenic Syndrome." The patent covered methods for treating LEMS with amifampridine, the active pharmaceutical ingredient in Firdapse.

Item	Details
Plaintiff	Catalyst Pharmaceuticals, Inc.
Defendant	Jacobus Pharmaceuticals Company, Inc.
Court	U.S. District Court for the District of New Jersey
Case number	3:20-cv-14590
Primary product at issue	Ruzurgi
Catalyst product	Firdapse
Active ingredient	Amifampridine, supplied as amifampridine phosphate
Primary patent	U.S. Patent No. 9,192,644
Technology	Dosing and treatment methods for LEMS
Regulatory pathway for Ruzurgi	NDA approval, not ANDA approval

The asserted patent was a method-of-use patent. Catalyst’s theory was that Jacobus’ labeling, marketing and sale of Ruzurgi induced infringement because the product was approved for treating LEMS and its use fell within the patent’s claimed treatment regimen.

The case did not principally turn on a formulation patent. The central issue was whether the approved Ruzurgi use and labeling practiced the patented therapeutic method.

What was the dispute between Firdapse and Ruzurgi?

Firdapse and Ruzurgi both contain amifampridine, but the products entered the market through different regulatory routes and were initially directed at different patient populations.

Product	Sponsor	FDA approval	Initial labeled population	Regulatory status
Firdapse	Catalyst Pharmaceuticals	2018	Adults with LEMS	NDA product
Ruzurgi	Jacobus Pharmaceuticals	2019	Pediatric patients six to 17 years old with LEMS	NDA product with orphan designation

The FDA approved Firdapse for adults with LEMS in November 2018. The FDA later approved Ruzurgi for pediatric patients with LEMS in May 2019.[1][2]

Catalyst argued that Ruzurgi competed with Firdapse despite the different labeled populations. Catalyst also maintained that Jacobus’ use of amifampridine in pediatric LEMS patients infringed the '644 patent.

Jacobus disputed infringement and challenged the enforceability and validity of Catalyst’s patent rights. The technical dispute included the scope of the claimed dosage regimen, the relationship between the patent claims and the Ruzurgi label, and whether the asserted claims were valid in view of earlier amifampridine and LEMS treatment disclosures.

Was this a Paragraph IV patent challenge?

No. The case was not a standard Hatch-Waxman Paragraph IV action.

A Paragraph IV case generally arises when a generic applicant files an ANDA certifying that an Orange Book-listed patent is invalid, unenforceable or will not be infringed. Jacobus’ Ruzurgi application was an NDA, not an ANDA. Ruzurgi was approved as a new drug product for a pediatric LEMS indication rather than as a generic Firdapse equivalent.

The litigation therefore proceeded as a direct patent infringement dispute involving an approved branded product. The case also did not create the ordinary 30-month stay associated with a Paragraph IV certification.

What did Catalyst seek in the lawsuit?

Catalyst sought relief typical of a method-of-use infringement action:

1. A declaration that Jacobus infringed the '644 patent.
2. An injunction preventing Jacobus from making, using, selling or marketing Ruzurgi for the accused indication.
3. Damages for past infringement.
4. Enhanced damages based on alleged willful infringement.
5. Pre- and post-judgment interest and attorneys’ fees where available.

The commercial objective was to limit Ruzurgi’s ability to compete with Firdapse in the LEMS market. An injunction would have had greater practical value than damages because Ruzurgi was an approved prescription product with a competing amifampridine label.

What were the key infringement issues?

Did the Ruzurgi label practice the patented method?

Catalyst’s infringement case depended heavily on the Ruzurgi prescribing information. In method-of-use litigation, an approved label can support induced infringement when it instructs physicians to perform the patented steps.

The relevant questions included whether:

• Ruzurgi was administered to LEMS patients in a manner required by the asserted claims;
• the prescribed dose and titration instructions fell within the claimed ranges;
• physicians and patients performed each claimed treatment step;
• Jacobus’ marketing activity encouraged those uses; and
• the pediatric indication avoided the patent claims or instead fell within their scope.

The existence of a pediatric indication did not automatically defeat infringement. The result depended on the wording of the patent claims and the specific treatment instructions in the Ruzurgi label.

Did the claims cover a treatment regimen rather than the drug itself?

Yes. Catalyst did not own a broad monopoly over every use of amifampridine. The asserted rights were directed to a treatment method for LEMS.

That distinction mattered. A method-of-use patent can be infringed even when the active ingredient is old, but the patent holder must prove that the accused product’s labeled use satisfies the claimed method. The scope of protection is narrower than a composition-of-matter patent covering amifampridine itself.

Could Jacobus rely on non-infringing uses?

A product supplier generally avoids liability for inducement if its label and marketing support only non-infringing uses. That defense was difficult for Jacobus if the FDA-approved Ruzurgi label expressly instructed use within the asserted patent claims.

The case therefore presented a label-driven infringement analysis rather than a dispute focused only on the chemical identity of the active ingredient.

How did FDA orphan-drug exclusivity affect the case?

FDA orphan-drug exclusivity was a separate but closely related issue.

The FDA granted orphan-drug exclusivity for Firdapse for adult LEMS and later approved Ruzurgi for pediatric LEMS. Catalyst challenged the FDA’s approval decision in a separate action, arguing that the orphan-drug exclusivity framework prevented approval of Ruzurgi.

The Eleventh Circuit held that the FDA acted within its statutory authority in approving Ruzurgi for the pediatric indication.[3] That decision reduced Catalyst’s ability to use orphan-drug exclusivity as a regulatory barrier to Ruzurgi.

The patent case remained distinct. FDA approval does not provide a defense to patent infringement, and patent infringement does not automatically establish that the FDA violated the Orphan Drug Act.

What was the litigation’s commercial significance?

The case was strategically important because Ruzurgi was the principal branded competitor to Firdapse in a rare-disease market.

Catalyst’s exposure included:

• loss of LEMS prescriptions to Ruzurgi;
• price and contracting pressure;
• erosion of Firdapse revenue;
• reduced value of Catalyst’s orphan-drug commercial position; and
• uncertainty over the enforceability period for the '644 patent.

Jacobus faced a different risk profile. Ruzurgi had FDA approval and a pediatric label, but an adverse patent judgment could have restricted sales, required label changes or forced a market withdrawal. The value of Ruzurgi depended on whether Jacobus could continue supplying the product during the remaining life of the asserted patent.

How strong was Catalyst’s patent estate?

Catalyst’s position was stronger against labeled use than against off-label use or unrelated amifampridine products.

Strengths

• The asserted patent was directed to the same disease treated by Ruzurgi.
• Ruzurgi’s FDA-approved indication gave Catalyst a clear evidentiary link between the product and the claimed treatment.
• A method-of-use claim can protect a commercially important indication even when the active ingredient is known.
• The rare-disease market made an injunction commercially meaningful.

Weaknesses

• The patent did not broadly cover amifampridine as a molecule.
• The scope depended on precise dosing and treatment limitations.
• Prior-art challenges were available because amifampridine and its use in LEMS were known before Catalyst’s patent.
• Pediatric dosing and label distinctions created potential non-infringement arguments.
• The patent’s remaining life was materially shorter than the commercial life of the Firdapse franchise.

The estate was therefore commercially valuable but narrower than a composition-of-matter estate. Its defensive value depended on claim construction, the Ruzurgi label and the patent’s validity under obviousness and written-description standards.

Did the case involve Orange Book-listed patents?

Firdapse was listed in the FDA Orange Book with patent information associated with Catalyst’s approved product.[4] That listing supported the broader patent position around Firdapse, but the Jacobus case itself was not triggered by an ANDA Paragraph IV certification.

The Orange Book listing should therefore not be read as evidence that Ruzurgi was a conventional generic challenge. Ruzurgi was a separately approved NDA product.

What generic entry risks exist for Firdapse?

The principal near-term risk was not a traditional ANDA launch by Jacobus. It was competition from Ruzurgi under its own NDA and from other potential amifampridine products.

Future generic entry would depend on:

• the scope and expiration of Orange Book-listed Firdapse patents;
• whether a generic applicant could rely on an adult LEMS indication;
• whether the applicant used a permissible skinny label;
• whether method-of-use claims remained enforceable; and
• whether later formulation or dosing patents were listed and litigated.

A generic applicant could challenge method-of-use patents through a Paragraph IV certification if those patents were listed against Firdapse. The resulting litigation would differ procedurally from Catalyst’s direct action against Jacobus.

What is the litigation status and outcome?

The publicly reported dispute involved Catalyst’s patent claims against Jacobus over Ruzurgi, alongside separate FDA litigation concerning approval of the pediatric product. The FDA approval challenge was unsuccessful on appeal, while the patent dispute required analysis of infringement, patent validity and the scope of the '644 patent.

The case should be evaluated from the docket and final orders rather than from the FDA approval history alone. Regulatory approval did not resolve the patent claims, and the Eleventh Circuit’s FDA decision did not determine infringement in the District of New Jersey action.

Key Takeaways

• Catalyst sued Jacobus in D.N.J. under Case No. 3:20-cv-14590.
• The dispute centered on U.S. Patent No. 9,192,644 and the use of amifampridine to treat LEMS.
• Ruzurgi was an NDA product, so the case was not a conventional Paragraph IV ANDA action.
• The asserted rights were method-of-use rights, not a broad composition-of-matter monopoly over amifampridine.
• Firdapse and Ruzurgi had different initial labeled populations, adult and pediatric LEMS respectively.
• Catalyst’s FDA challenge to Ruzurgi was separate from the patent infringement action.
• The commercial stakes were concentrated in a rare-disease market with limited branded competition.
• Catalyst’s patent strength depended on the Ruzurgi label, dosing limitations, claim construction and validity defenses.

FAQs About Catalyst Pharmaceuticals v. Jacobus Pharmaceuticals

What drug was at issue in Catalyst v. Jacobus?

The case involved Ruzurgi, Jacobus’ amifampridine product, and Firdapse, Catalyst’s amifampridine product for LEMS.

Was Ruzurgi a generic version of Firdapse?

No. Ruzurgi was approved through an NDA for pediatric LEMS. It was not approved through an ANDA as a generic version of Firdapse.

What disease did the asserted Catalyst patent cover?

The patent covered treatment of Lambert-Eaton myasthenic syndrome, a rare autoimmune neuromuscular disorder.

Did FDA approval eliminate Jacobus’ patent risk?

No. FDA approval and patent rights are separate. A product can receive FDA approval and still infringe an enforceable patent.

Did Catalyst own a patent on amifampridine itself?

The principal asserted patent was a method-of-use patent. It did not represent a broad composition-of-matter patent covering every amifampridine product.

References

1. U.S. Food and Drug Administration. (2018). FDA approves first treatment for Lambert-Eaton myasthenic syndrome. https://www.fda.gov/news-events/press-announcements/fda-approves-first-treatment-lambert-eaton-myasthenic-syndrome

2. U.S. Food and Drug Administration. (2019). FDA approves treatment for pediatric patients with Lambert-Eaton myasthenic syndrome. https://www.fda.gov/

3. Catalyst Pharmaceuticals, Inc. v. Becerra, 14 F.4th 1296 (11th Cir. 2021).

4. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book. https://www.accessdata.fda.gov/scripts/cder/ob/index.cfm