In recent years, there has been much discussion regarding patents for blockbuster drugs being invalidated in Canada for lacking utility. In Canada, the invention claimed in the patent must be useful. However, the utility does not have to be demonstrated at the time of filing. Patentees are permitted to rely on a sound prediction of utility.
In deciding an invalidity challenge involving the utility of the patent, Canadian Courts first construe the "promise of utility" from the patent. The Courts then consider whether that promise has been demonstrated as of the filing date of the patent, or whether the patentee must rely on a sound prediction of utility in fulfilling the promise. If the promised utility is demonstrated as of filing, the inutility challenge fails. The Courts generally accept that proof of that utility need not be in the patent.
However, if the patentee needs to rely on the sound prediction of utility, the Court moves on to a further test: 1) identify the factual basis for the prediction; 2) determine whether there is a sound line of reasoning from the prediction to the promise of utility; and 3) decide whether the factual basis and the line of reasoning are properly disclosed in the patent specification. Without disclosure of the factual basis and sound line of reasoning, the inventor is seen to be giving nothing to the public in exchange for the monopoly.
The idea of sound prediction was originally incorporated into Canadian law as a patent-friendly policy, as it allowed protection of useful inventions without the need to make and test every compound covered by a patent. However, in practice, the lower courts have used this doctrine to invalidate many pharmaceutical patents. The current heightened standard for utility has no statutory basis and contravenes Canada's treaty obligations and international norms.
The construction of the "promise" is often the key to the utility discussion, as it will determine the level of utility the patentee will have to meet in order to maintain the patent's validity. Where there is no explicit promise provided in the specification, the courts have agreed that only a "mere scintilla" of utility is required.
In many past pharmaceutical cases where the Court has construed an explicit promise from the patent, the threshold of utility required will generally only be satisfied if the patent contains longer term proof of utility within the patent. The promise in some of these earlier cases has been held to be, for example, treatment of a chronic disease in humans; long term treatment of a disease in humans; all of the stated advantages in the patent; and a reduction in side effects. With these types of promises, even clinical data in the patent was often held not to be sufficient to help meet the sound prediction test.
More recently, the Courts have started to recognize that the "promise" is different from the objects, advantages and mere statements of a practical purpose, which are also found in a patent. Furthermore, the Court has allowed different claims to have different promises. In particular, compound claims, process claims, use claims, and claims to medicaments containing compounds all have been held to have different promises when considering inutility allegations. Finally, there may be recognition from the Court that the disclosure element of this test can be met by taking into account the common general knowledge of the person skilled in the art. The Supreme Court will be hearing a case focused on this issue in November 2014. That decision will be anxiously awaited by patentees and challengers alike.
Thus, in the meantime, it appears that the pendulum may be swinging back towards centre when it comes to patentees trying to uphold their patents in Canada. While the "promise" doctrine and the enhanced disclosure requirements (which the courts have now suggested may not be so stringent) are still unique to Canada, an invalidity challenge based on inutility may not be the "crushing hammer" that it used to be. Patents covering drugs are being upheld in the face of such challenges, when the "promise" is construed reasonably, and the patentee has made appropriate disclosures.
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