Eli Lilly Canada Inc v Apotex Inc, 2015 FC 875
Pharmaceutical patent-filers face more uncertainty as to the appropriate time to file patent applications, after this Federal Court (“FC”) decision. This FC decision dealt with an application to prohibit the issuance of a Notice of Compliance (“NOC”) until the expiry of an existing patent. The defendant was not successful in its allegations that the existing patent was invalid on the grounds of insufficiency, same-invention and obviousness double patenting. The FC granted the prohibition order, but noted in its analysis that the law is unsettled when it comes to determining the appropriate date for assessing obvious-type double patenting. This case has been appealed and is scheduled to be heard on May 5, 2016.
Apotex Inc (“Apotex”), the respondent, sought a Notice of Compliance (“NOC”) in respect of Apo-Tadalafil, a generic version of tadalafil – a drug used to treat erectile dysfunction (“ED”), among other things. Eli Lilly Canada Inc (“Lilly”), the applicant, markets tadalafil under the brand name Cialis. Lilly sought an order under section 6 of the Patented Medicines (Notice of Compliance) Regulations, SOR/93-133 (“PMNOC”) to prohibit the issuance of the NOC until the expiry of Lilly’s Canadian Patent No. 2,226,784 (the “’784 Patent”), which is listed against Cialis on the Patent Register.  The relevant claims of the ‘784 Patent relied on tadalafil to treat erectile dysfunction (“ED”). Apotex alleged that the ‘784 Patent was invalid for double patenting of the invention claimed in Canadian Patent No. 2,181,377 (the “‘377 Patent’) and for insufficiency.
Only the validity of the ‘784 Patent was an issue in this case, not infringement, as Apotex did not contest that its Apo-Tadalafil product would infringe claims 1, 2, 4, 9, 12, 14, 15 and 18 of the ‘784 Patent. 
The FC allowed Lilly’s prohibition application, noting that the ‘784 Patent was not invalid for insufficiency, same invention-type or obviousness-type double patenting.
The ‘377 Patent
The ‘377 Patent claimed several novel compounds, including tadalafil, pharmaceutical compositions and the use of these compounds in the treatment of various disorders where the inhibition of PDE V was thought to be beneficial.  The 377 Patent did not discuss ED in any way. [81, 117]
The ‘784 Patent
The ‘784 Patent involved using of some of the compounds claimed in the ‘377 Patent in the treatment of ED. The FC agreed with Lilly that the promise of the ‘784 Patent was on the effectiveness of the compounds to treat ED, not the specific route of administration. Apotex alleged that the ‘784 Patent was invalid for double patenting over the ‘377 Patent and for insufficiency. 
The doctrine of double patenting, “prevents a patent holder from ‘evergreening’ its patent by obtaining a second patent for the same invention for which a patent has already been granted.” 
Same Invention-type Double Patenting
The FC found that both the ‘784 Patent and the ‘377 Patent (collectively, the “Patents”) disclosed tadalafil and disclosed in vitro testing, but that, unlike the ‘784 Patent, the ‘377 Patent did not discuss ED in any way.  After finding that the ‘377 Patent did not extend to the use of tadalafil to treat ED, the FC held that Apotex’ allegation of same invention-type double patenting was unsubstantiated. 
Obviousness-type Double Patenting
To assess obviousness-type double patenting, the FC compared the claims of the Patents to determine whether the claims of the ‘784 Patent were patentably distinct from the claims made in the ‘377 Patent.  This case was the second PMNOC case dealing with the Patents, the other case being Eli Lilly Canada v Mylan Pharmaceuticals, 2015 FC 17 (“Mylan Pharmaceuticals”) (appeal pending). The FC in the case at hand did not follow the FC’s determination in Mylan Pharmaceuticals of the appropriate date for assessing obviousness-type double patenting.  In Mylan Pharmaceuticals, the FC held that the relevant date was the priority date of the earlier patent. The FC in the case at hand considered the priority date of the second patent to be the relevant date, since the common general knowledge may have advanced in the interim.
In the end, however, the FC declined to come to any firm conclusion on this legal issue, noting that both relevant dates would yield the same result. The FC went on to hold that it was not obvious that the compounds claimed in the ‘377 Patent could be used to treat ED. Apotex’s allegation of obviousness-type double patenting was thus rejected.
Several of the relevant claims in the ‘784 Patent extended to hydrates of tadalafil.  Apotex alleged that the ‘784 Patent was invalid for insufficiency because it failed to provide enough information to enable a person of ordinary skill in the art (“POSITA”) to produce a hydrate of tadalafil.  The FC found that the ‘784 Patent disclosed a general method for solvent formulation.  The FC preferred the evidence of Lilly’s expert and found that there was “adequate disclosure in the 784 Patent to enable the production of solvates of tadalafil and 3-methyl tadalafil and that, from there, the skilled person, relying on his or her common general knowledge, would be able to create and if necessary modify reaction conditions so as to favour hydrate formation.”  Apotex’s allegation of insufficiency was rejected.
This was the second PMNOC case to favour Lilly in regard to allegations that Lilly’s ‘784 Patent was invalid due to double patenting of the invention in the earlier ‘377 Patent. The FC noted that the law remains unsettled in regard to the appropriate date for assessing obviousness-type double patenting. Both this case and Mylan Pharmaceuticals have been appealed.