Patent applications filed by Natco Pharma Limited and Pfizer Inc., et al. v. Dexcel Pharma Technologies Limited, et al. Tafamidis case

Contents

Patent applications filed by Natco Pharma Limited

General information

FDA: Novo Nordisk failed to report deaths of weight-loss drug patients

FTC monitoring how drug companies react to patent cliff, official says

Intellectual Property

Pfizer Inc., et al. v. Dexcel Pharma Technologies Limited, et al.: Tafamidis case

Patent applications filed by Natco Pharma Limited

We analysed Natco's patent application and evaluated its development activities. We tried to gather data on PCT applications filed over the last 2 years for this analysis. There is a lag in the publication of applications, so this analysis indicates Natco’s development activities from about 3-4 years ago. Some comments regarding PCT applications are summarised below.

Some general comments

• Natco identifies molecules in very late stages of development, possibly in Phase III.
• Those patent families that are not interesting from a business perspective are abandoned immediately. There appears to be a robust patent portfolio management system in place within the company.
• Mainly, applications are related to chemistry and chemical processes.
• There is NCE-related work in their R&D, though (perhaps) it has so far had limited success.
• Agrochemical marketed formulations are usually protected by patent families.
• All patent families, whether they’re related to Pharma or agrochemicals, are assigned to Natco Pharma Limited.

General information

FDA: Novo Nordisk failed to report deaths of weight-loss drug patients

In a warning letter dated March 5, the Food and Drug Administration cited five cases where patients taking the drugs experienced a stroke, considered suicide or died – one of them by suicide – all of which Novo Nordisk failed to report properly. News here

FTC monitoring how drug companies react to patent cliff, official says

• FTC focuses on healthcare to protect against high costs • Patents for top-selling drugs like Keytruda and Eliquis expiring by decade's end • FTC blocks deals to prevent reduced competition and innovation slowdown News here

Intellectual Property

Pfizer Inc., et al. v. Dexcel Pharma Technologies Limited, et al.: Tafamidis case

On 10 March 2026, the U.S. District Court for the District of Delaware issued a Memorandum Opinion denying a motion by Defendants Cipla Limited and Hikma Pharmaceuticals USA Inc. to exclude the expert testimony of Dr. Adam Matzger. The litigation, initiated by Pfizer Inc. and others, alleges that the defendants' generic versions of tafamidis infringe several patents, including U.S. Patent No. 9,770,441 (the '441 patent). List of OB-listed patents:

U.S. Patent No. 9,770,441 (the '441 patent) is titled "Crystalline Solid Forms of 6-carboxy-2-(3,5-dichlorophenyl)-benzoxazole". It covers the active pharmaceutical ingredient tafamidis, used in Pfizer’s drug Vyndamax for treating transthyretin-mediated amyloidosis. The patent specifically claims "Form 1" of tafamidis, a crystalline version defined by its unique physical signature rather than just its chemical formula. Claim 1: Claim 1 is the sole independent claim and describes a crystalline form of tafamidis that possesses at least one of the following three analytical parameters: • Raman Spectroscopy: A Raman shift peak at 1292 + 2 cm⁻¹. • Powder X-ray Diffraction (PXRD): A peak at a diffraction angle (2 theta) of 28.6 + 0.2. • Solid-State NMR Spectrum: 13C chemical shifts at 120.8 + 0.2 and 127.7 + 0.2 ppm. Scope and Additional Details

• Dependent Claims: The patent contains 16 claims in total. While Claim 1 provides a choice of any one parameter, other claims (such as Form 1 characterisation) may require multiple properties, including an additional Raman shift peak at 1615 +2 cm⁻¹.
• Legal Significance: The core of the dispute with generic manufacturers (Cipla, Hikma, Apotex) is whether their generic tafamidis exhibits any of these specific fingerprints. The patent distinguishes this crystalline form from other versions, such as amorphous forms or different solvates (e.g., Form 2 THF solvate, Form 4, or Form 6).
• Expiration: The patent was issued on 26 September 2017, and has an anticipated expiration date of 31 August 2035.

The Defendants challenged Dr. Matzger’s testimony on two primary technical grounds under the Daubert standard, which requires expert testimony to be reliable and relevant:

• Curve Fitting (Deconvolution): Defendants argued that Dr. Matzger’s use of "curve fitting" to identify overlapping peaks in Raman spectra was arbitrary, lacked validation, and was not a methodology accepted in the scientific community for identifying unknown peaks. They contended his results were theoretical models influenced by user bias.
• Raman Mapping: Defendants sought to exclude testimony regarding Raman mapping, claiming Dr. Matzger failed to use reference standards to prove that identified peaks were tafamidis rather than excipients, and failed to provide data proving his instrument was properly calibrated.

The Court rejected these arguments, emphasising the liberal admissibility policy. Regarding curve fitting, the Court found that Dr. Matzger provided a logical basis for his opinion: he identified overlapping peaks through visual inspection and used software-driven deconvolution methods recommended by the instrument manufacturer and supported by scientific literature. Judge Williams noted that disagreements over calculation methodology go to the weight of the evidence, not its admissibility. Regarding Raman mapping, the Court ruled that Dr Matzger’s explanations, such as the ability to distinguish crystalline API from liquid excipients, were sufficient to support his conclusions, which flowed reliably from his methodology. The Court concluded that any perceived weaknesses in his foundation or lack of independent calibration data should be addressed through vigorous cross-examination and competing expert testimony at trial, rather than pre-trial exclusion. Consequences of this decision

• Preservation of Plaintiffs' Infringement Case: By allowing Dr. Matzger’s testimony, the court ensures that Pfizer can present its core scientific evidence regarding the '441 patent. Since the independent claim of the '441 patent relies heavily on specific Raman spectrum peaks, excluding this testimony might have effectively ended Pfizer's ability to prove infringement on that patent.
• Methodological Precedent: The ruling reaffirms that deconvolution and curve fitting are admissible techniques in patent litigation, even when contested. This lowers the barrier for experts to use advanced software-assisted analysis to identify chemical structures that are obscured in raw data.
• Focus on Trial Over Gatekeeping: The Judge’s emphasis on vigorous cross-examination as the traditional and appropriate means of attacking shaky evidence signals a preference for resolving technical disputes during the trial phase rather than through pre-trial motions. This may discourage future defendants from filing overly broad Daubert motions when the dispute centres on the strength of a conclusion rather than the validity of the underlying science.

Decision here