CA – Revendication visant une posologie trouvée non brevetable

La décision #1292 du Commissaire résulte en le rejet “de toutes les revendications au motif qu’elles sont évidentes. Conséquemment aux modifications apportées aux revendications en réponse à la décision finale, l’examinateur a soutenu que les revendications visaient aussi une méthode de traitement non brevetable puisqu’elles comprenaient un schéma posologique. La Commission a conclu que les revendications étaient évidentes et qu’elles visaient une méthode de traitement médical non brevetable en raison du fait qu’elles cherchaient à circonscrire un intervalle à l’intérieur duquel les médecins doivent exercer leurs compétences et leur jugement professionnel dans chaque cas particulier. En conséquence, la Commission a recommandé que la demande soit rejetée.”


[9] The two issues which have been considered by the Board are as follows:

(1) Would claims 1-7 have been obvious in view of the art cited by the Examiner?

(2) Do claims 1-7 fail to comply with section 2 of the Patent Act for being directed to a method of medical treatment?


[10] There are only seven pending claims relating to the use of botulinum toxin, which are reproduced below for convenience:

1. The use of from 50 to 300 units of a botulinum toxin for treating pain associated with a muscle disorder, wherein the muscle disorder is a spasticity condition secondary to a stroke or a cerebral vascular event.
2. Use according to claim 1 which is intramuscular.
3. Use according to claim 1 wherein the botulinum toxin is selected from the group consisting of botulinum toxin types A, B, C, D, E, F, and G.
4. Use according to any one of claims 1 to 3 in a human patient.
5. Use of from 50 to 300 units of a botulinum toxin for treating pain associated with spasticity of an arm, hand, or leg, wherein the spasticity is secondary to a stroke.
6. Use according to claim 5 wherein the botulinum toxin is selected from the group consisting of botulinum toxin types A, B, C, D, E, F, and G.
7. Use according to claim 6 wherein the botulinum toxin is type A.

It is well known that a muscle becomes spastic because of abnormal efferent signals from the central nervous system (CNS) which travel through motor neurons to the peripheral muscle. Contrarily, pain perceived as arising in a muscle is due to signals which travel from the periphery along sensory neurons to the CNS. Thus, not only is the direction of the neural traffic the opposite (from CNS to periphery for spasticity vs. from periphery to CNS for pain) but as well the pathways themselves differ (motor neurons for spasticity vs. sensory neurons for pain). Clearly therefore treating pain is not the same as or inherent in treating spasticity.

[12] Based on the above arguments the Applicant contends that the claims are restricted to treating pain only and that the spastic muscle itself is not treated. This is consistent with the views expressed by the Applicant at the hearing. The relevant portions of its written submissions are reproduced below:

Claims 1-7 are not directed to a functional improvement. That is the claims do not encompass relief of the spastic muscle condition. Relief of the spastic muscle by paralysis (i.e. muscle tone reduction) requires a high dose of the botulinum toxin. The inventors discovered that a low dose (i.e. 50-300 units) of a botulinum toxin can be used to treat the pain of post-stroke spasticity, separate from the muscle spasticity itself.

[17] At page 8 we find one reference which might be said to allude to treatment only of pain. It is stated in relation to the dosages used in human therapeutic applications that the dosage is (our emphasis added):

preferably in the ranges from about 80 to about 460 units per patient per treatment, although smaller or larger doses may be administered in appropriate circumstances such as up to about 50 units for the relief of pain and in controlling cholinergic secretions.

[18] If it were possible to treat pain separately from spasticity, it would appear from the above passage that 50 units or thereabouts is the upper limit. Given that the claims specify 50 to 300 units, one must conclude that the claims indicate something other than the sole treatment of pain. Further, at page 10 there is a general discussion of the Examples and the procedure used. At lines 8-13 it is stated (our emphasis added):

Following injection, it is noted that there are no systemic or local side effects and none of the patients are found to develop extensive local hypotonicity. The majority of patients show an improvement in function both subjectively and when measured objectively.

[19] Clearly functional improvements are important overall, contrary to Applicant’s submissions.

[20] In summary, the Board cannot accept Applicant’s contentions that pain is treated separately from spasticity. In view of the foregoing, the wording of the claims, namely, “for treating pain”, in conjunction with the claimed range, cannot be interpreted to mean that pain only is treated. With this interpretation in mind, the Board will turn its attention to the outstanding issues.