Claiming a treatment by its intended patient population continues to be a successful strategy for pharmaceutical patent practitioners confronted with close prior art, most recently in an appeal to the Patent Trial and Appeals Board (“PTAB”) from a final rejection in Ex parte Kouda et al., 2019 PAT. APP. LEXIS 9312 (PTAB October 10, 2019).
Ex parte Kouda involved the use of glycine to treat insomnia, and particularly the use of glycine to improve deep slow wave sleep. The main claim on appeal recited:
A method of shortening slow wave sleep latency, comprising administering a composition comprising glycine to a human subject in need of such shortening, wherein the composition comprises 5 g or less of amino acids other than glycine.
The Examiner had rejected the claim based on prior art teachings that stress is one of the major causes of insomnia, that glycine relieves stress, and that glycine has sedative properties.
To overcome the rejection, the Applicant submitted an expert declaration explaining that all insomnia patients are not the same, and not all insomnia patients require improved slow wave sleep. As explained by the PTAB:
not all sleep disruptions leading to insomnia affect the same stage of sleep. … patients presenting with insomnia do not necessarily need improved slow wave sleep, as evidenced by successfully treating insomnia with sleep aids that either do not have an effect on slow wave sleep or may even disrupt slow wave sleep.
Based on this record, the PTAB reversed the Examiner’s final rejection. According to the PTAB,
Appellant has presented a sufficient evidentiary basis from which to conclude that not all insomnia has the same underlying etiology, therefore, treatment with glycine would not necessarily have the same effect on all insomnia patients. In other words, administering glycine to treat a patient with stress-induced insomnia, as taught by the cited prior art, will not necessarily shorten slow wave sleep latency or extend the duration of slow wave sleep, because the underlying etiology of the patient's insomnia may not be associated with slow wave sleep.=
We are not happy with the words chosen by the PTAB to explain their decision, particularly the PTAB’s use of the word “necessarily,” which suggest that their decision was underpinned by a lack of “inherency” in the prior art. As we have previously blogged, inherency is usually an inappropriate vehicle for establishing an obviousness rejection. See Millennium Pharm., Inc. v. Sandoz Inc., 862 F.3d 1356 (Fed. Cir. 2017).
Nevertheless, we believe that the PTAB got it right. The point the PTAB was trying to make was that there are different types of insomnia patients. There was no evidence in the record that prior art patients treated with glycine for stress-induced insomnia are the same patients the claims were written to cover, whose insomnia was caused by an inability to enter slow-wave sleep. Hence, the rejection could not stand.