Patenting Polymorphs at the EPO

Video overview:

Novelty and Inventive Step

• Prior art must necessarily lead to the claimed polymorph to be novelty destroying
• Watch out for inherent disclosures in prior art—methods may implicitly produce polymorphs even if structural data isn’t provided.
• Provide experimental evidence if needed to show prior art does not produce the claimed polymorph.
• Emphasize any advantages or unexpected properties of the polymorph, ideally supported by data, to support an inventive step, in the application.
• Highlight advantages of the polymorph versus other forms.

Clarity

• Provide a clear, precise definition of the polymorph.
• Clearly define the crystalline form using appropriate physicochemical parameters and measurement conditions.

Sufficiency

• Clearly describe how to prepare the polymorph. If preparation requires seeding crystals, disclose how to prepare the seed in the application.