On August 20, 1990, Orasure Technologies Inc. (the "Applicant") filed Canadian patent application number 2,023,636 entitled "Oral Immunoglobulin Collection for Immunoassay" ("the '636 application") and subsequently on February 27, 1991 filed Canadian patent application number 2,076,754 entitled "Oral Collection for Immunoassays" ("the '754 application). Examination was requested for the '636 application on July 22, 1997. The applicant requested examination and special order status, for expedited prosecution, of the '754 application on October 2, 1998. The application issued to patent on July 25, 2000.

On December 8, 2003, the Examiner issued a Final Action against all claims of the '636 application for overlapping the subject matter of '754 patent. The Applicant submitted that since both applications were co-pending before the Canadian Patent Office, both were laid open to public inspection well in advance of examination, and examination of both applications was requested within several months of each other, the Examiner failed to discharge his or her duties during pendency of the two applications to properly search and raise the relevant overlapping subject matter objection against both the '754 application and the '636 application. As such, the Applicant "cannot now be expected to suffer by having to remove valid subject matter from one application because the Examiner considers that an already issued patent of the same Applicant is directed to the same subject matter….and cannot be disadvantaged by having to give up subject matter in that application because of errors made by the Examiner during the examination process" (C.D. 1291 Application No. 2,023,636, paragraph 13).

The Applicant further argued that since the '636 application, if granted, would expire before expiry of the '754 patent, there would be no extension of the monopoly and thus the Applicant should be entitled to the earlier date of invention of the '636 application.

The Commissioner did not directly address the issue of whether the Examiner failed to discharge his or her duties during pendency of the two applications to properly search and raise the relevant overlapping objections against both applications. However, the Commissioner suggests that there is no onus on the Patent Office to raise such double patenting objections against both applications and that, in accordance with subsection 30(1) of the Patent Rules, once an Examiner has "reasonable grounds" to believe that an application complies with the Patent Act and Patent Rules, the Applicant shall be notified that the application has been found allowable. Thus, once the Examiner had reasonable grounds to believe that the '754 application was allowable, it was allowed to issue to patent.

At present, double patenting may be found against two patents to the same applicant where the claims of the two patents are coterminous, or where the claims of one patent are considered obvious in view of those of the other patent. Ultimately, after performing an analysis of the claims, the Commissioner found that the claims of the '636 application are not coterminous with those as issued in the '754 patent, but that most of the claims are not patentably distinct and as such, are rejected for obviousness-type double patenting.

In view of this decision, patent applicants would be well advised to always review the claims of related, co-pending applications once a notice of allowance has been issued against a particular application, even where the co-pending applications have an earlier filing date. This is especially important where obviousness-type double patenting is cited, as it is conceivable that those claims of the issued patent may be narrower than those of an application still pending, but nevertheless, subject the claims of the pending application to obviousness-type double patenting objections.