Court Adopts the Patent's Own Definition of Crystalline Form A in Genentech's Evrysdi Suit Against Natco, Sun, and Zydus.

The case

The opinion issued in Genentech, Inc. v. Natco Pharma Limited, Consol. No. 2:24-cv-10567-JCG-JSA (D.N.J.), an ANDA case. The caption lists Genentech, Inc., Hoffmann-La Roche Inc., and PTC Therapeutics, Inc. as plaintiffs and Natco Pharma Limited, Sun Pharmaceutical Industries Ltd., Sun Pharmaceutical Industries Inc., Zydus Lifesciences Global FZE, Zydus Lifesciences Ltd., and Zydus Pharmaceuticals (USA) Inc. as defendants. Judge Jennifer Choe-Groves of the U.S. Court of International Trade is sitting by designation. The drug is EVRYSDI, or risdiplam, an oral treatment for spinal muscular atrophy. The opinion says Genentech and Roche filed a first amended complaint on February 12, 2026 alleging that Natco's ANDA to market a generic version infringes the '789 patent, and that the court consolidated four cases under No. 24-10567 for pretrial purposes.

The patent and the claim

U.S. Patent No. 12,122,789, titled Forms of Pyrido[1,2-a]Pyrimidin-4-One Derivatives, Its Formulation and Its Process of Making, issued October 22, 2024. Claim 1 recites a solid form of a compound of formula (I) that is "crystalline Form A" having an x-ray powder diffraction pattern with at least two peaks selected from 8.3, 11.4, 15.1, 15.9, 17.0, 24.0, and 25.6 degrees two-theta, each plus or minus 0.2. The disputed term appears in claims 1, 2, 4 through 8, 12 through 21, 30, and 31. The court had earlier adopted agreed constructions of "effective amount" in U.S. Patent No. 9,586,955 and "therapeutically effective amount" in U.S. Patent Nos. 9,969,754 and 11,827,646.

The dispute

The plaintiffs said no construction was needed because the patent defines Form A as "the crystalline anhydrous polymorphic Form A" of the compound, risdiplam, and each claim recites the properties that must be shown for that claim. The defendants proposed "the risdiplam crystalline form described in the specification as Form A, having all of the characteristics assigned to Form A in the specification," arguing that a crystalline form missing any of those attributes is not Form A and that confirming Form A is a separate predicate step.

The ruling

The court held that the specification at column 7, lines 43 to 46 gives an explicit definition. It noted that dependent claims describe Form A by different XRPD peak combinations and that the specification describes many Form A embodiments with different peaks, quoting the specification's statement that "[o]ptionally, all five peaks may be present." Requiring all of the characteristics assigned to Form A in the specification, it held, would improperly import embodiments from the specification into the claim language. Citing Interval Licensing LLC v. AOL, Inc., the court construed "crystalline Form A" as the specification defines it, "the crystalline anhydrous polymorphic Form A of 7-(4,7-diazaspiro[2.5]octan-7-yl)-2-(2,8-dimethylimidazo[1,2-b]pyridazin-6-yl)pyrido[1,2-a]pyrimidin-4-one." The opinion notes that the defendants reserved indefiniteness arguments under 35 U.S.C. 112 for summary judgment or trial and raised written description and enablement arguments in their brief. The hearing was held September 17, 2026 without expert witnesses.