National or multi-jurisdictional class actions are common in Canada, regularly giving rise to parallel and overlapping cases across multiple provinces. This often happens in life sciences litigation, where claims relating to the same drug or device are advanced in multiple jurisdictions, leading to carriage disputes and allegations of abuse of process. Without a national framework for managing class proceedings, Canadian courts are often called upon to decide how overlapping class actions should proceed. National coordination has emerged as a response to these challenges, which, if unaddressed, have the potential to undermine a core objective of class proceedings-judicial economy.
The Ontario Superior Court recently considered these issues in Strathdee v. Johnson & Johnson Inc., 2026 ONSC 1186, a proposed multi-jurisdictional class action arising from alleged injuries associated with talc-based baby powder products. Justice Leiper refused to stay the Ontario action as an abuse of process notwithstanding the prior certification of a parallel class action in British Columbia. Justice Leiper held that the Ontario action remained the preferable procedure for the Ontario-defined class, with any overlap to be managed through inter-jurisdictional cooperation and case management. In doing so, Justice Leiper rejected the defendants' submission that the existence of overlapping proceedings was sufficient to preclude the Ontario action and instead treated the identified differences between the proceedings as material to both the abuse of process and preferability analyses.
Key Takeaways
Justice Leiper's decision in Strathdee offers several practical takeaways for life sciences companies navigating multi‑jurisdictional product liability litigation in Canada:
- Overlap between parallel proceedings alone may be insufficient to justify a stay. Strathdee suggests that overlapping class actions arising from the same product may proceed in parallel when they are not "carbon copies", with the result likely to turn on the degree of overlap between the proceedings. For defendants, the decision provides practical guidance on the degree of overlap required before parallel proceedings may be treated as sufficiently duplicative to support a stay, including by reference to class definition, causes of action, alleged injuries and temporal scope.
- Access to justice may outweigh efficiency-based objections. Strathdee suggests that access to justice—one of the fundamental objectives of class action litigation—may outweigh efficiency-based objections where a parallel proceeding may not adequately address the claims of all putative class members. For defendants, this underscores the importance of showing not only that a parallel proceeding exists, but that it adequately captures the relevant class, claims and scope of relief.
- A coordinated national defence strategy may be increasingly important. Strathdee highlights the potential value of early, cross‑provincial assessment of overlapping actions and a coordinated approach to stay motions and broader procedural strategy. Even where a stay is not granted, defendants may nevertheless be expected to take practical steps to reduce duplication, reinforcing the importance of a national defence strategy from the outset.
The Strathdee Decision: Key Considerations
The defendants, Johnson & Johnson Inc., moved to have the class action stayed as an abuse of process given the existence of two overlapping proceedings in British Columbia and in Quebec. Although the Quebec action was authorized and upheld on appeal, it appeared dormant, and Justice Leiper therefore focused her analysis on the relationship between the Ontario and British Columbia proceedings.
The plaintiffs sought dismissal of the defendants' motion to stay and an order certifying the Ontario action under the Class Proceedings Act, 1992 (CPA). In prior reasons dated June 25, 2025, Justice Leiper had already concluded that the certification criteria under s. 5(1)(a)-(c) and (e) of the CPA were satisfied, leaving preferability under s. 5(1)(d) as the outstanding certification issue. The plaintiffs also sought leave to amend the claim to add a new statutory cause of action under the New Brunswick Consumer Product Warranty and Liability Act.
This produced three remaining questions: (1) whether the Ontario proceeding should be stayed as an abuse of process; (2) whether the Ontario proceeding was the preferable procedure for resolution of the common issues; and (3) whether leave should be granted to add a new statutory cause of action under the New Brunswick Consumer Product Warranty and Liability Act. While Justice Leiper addressed each of these issues, the discussion below focuses on the abuse of process and preferability analyses, which bear most directly on questions of national coordination.
1. Refusal to Stay the Ontario Proceeding for Abuse of Process
Despite the defendants' submission that allowing the Ontario action to proceed would offend principles of comity, create a risk of inconsistent findings and generate inefficiency, Justice Leiper refused to stay the Ontario action as an abuse of process. Justice Leiper emphasized that parallel class proceedings are not inherently abusive. The analysis instead turns on the degree of overlap between proceedings, rather than any presumption that only one action should proceed. Where parallel proceedings are essentially "carbon copy" actions, the resulting duplication may offend principles of comity and judicial economy, such that a stay may be warranted.
Justice Leiper found that the Ontario and British Columbia actions were not carbon copies. Although both actions concerned the same product, the Ontario proceeding differed in material respects, including the causes of action advanced, the categories of injury alleged and the absence of the same temporal limitations on product use, even though they clearly arose from the same allegations of injury arising from the use of talc. These differences meant the proceedings were not sufficiently duplicative to warrant a stay and that the Ontario action offered the prospect of broader access to justice for class members whose claims fell outside the narrower scope of the British Columbia proceeding.
Justice Leiper also rejected the notion that national coordination should operate as a rigid "first-to-file" or "first-to-certify" rule. The fact that related proceedings may have been commenced or certified earlier in another jurisdiction does not automatically determine where litigation should proceed. Instead, courts must assess the scope of the proposed classes and claims, together with broader considerations of fairness, comity and the administration of justice. In this case, the Court was satisfied that permitting the Ontario action to proceed—on the basis of a distinct certification record and broader claims—would not undermine comity or the integrity of the judicial process.
2. Preferability of the Ontario-Defined Class Proceeding
Justice Leiper certified the Ontario action on the basis that it satisfied the preferability requirement under s. 5(1)(d) of the CPA. To guide her analysis, Justice Leiper recited the established two‑part preferability inquiry: whether a class proceeding constitutes a fair, efficient and manageable method of advancing the claims, and whether it is preferable to other reasonably available procedures, having regard to the objectives of judicial economy, behaviour modification and access to justice.
On the first branch of the inquiry, Justice Leiper rejected the defendants' submission that a class proceeding was not preferable because the range in relative risks associated with the perineal use of baby powder, as well as the different subtypes of epithelial ovarian cancer (EOC), meant that individual causation trials would overwhelm any utility of the proposed common issues. Justice Leiper instead concluded that the availability of expert evidence on the causation and association issues, together with the finite set of EOC subtypes, made those issues suitable for determination on a common issues basis, supporting the conclusion that a class proceeding was preferable.
On the comparative branch of preferability, Justice Leiper again examined the degree of overlap between the Ontario and British Columbia proceedings. For the reasons outlined above, the Ontario action was materially broader in both class definition and legal scope, such that the Court was not satisfied that the claims of all Ontario class members would be adequately addressed elsewhere. In those circumstances, refusing certification on the basis of overlapping proceedings would risk undermining access to justice for class members whose claims fell outside the narrower parameters of the parallel action.
Although the version of the CPA applicable to the Ontario action pre-dated the 2020 amendments, Justice Leiper's analysis reflected the same underlying concern now expressly addressed in the amended statute: how courts should approach parallel proceedings in multiple Canadian jurisdictions in a manner that serves the ends of justice and promotes judicial economy. On the record before the Court, certification of the Ontario action best advanced the objectives of the class proceedings regime, leaving questions of coordination and duplication to be addressed, if necessary, through subsequent case management.
3. Managing Overlap Through Coordination and Case Management
Although Justice Leiper declined to stay the Ontario action, she acknowledged that parallel class proceedings can give rise to real risks, including duplication, confusion and inconsistent outcomes. Rather than treating those risks as determinative, Justice Leiper emphasized that coordination and active case management provide a practical and flexible means of managing overlap in multi‑jurisdictional class actions.
Justice Leiper indicated that, to the limited extent the Ontario and British Columbia actions overlapped, counsel were expected to cooperate and communicate, and to rely on case‑management tools to promote efficiency and mitigate duplication. This included keeping courts in each jurisdiction apprised of procedural developments and, where appropriate, coordinating steps such as discovery to reduce inefficiency. At the same time, Justice Leiper made clear that these measures remained subject to ongoing judicial oversight, and that stays, decertification or other procedural adjustments could be revisited should circumstances evolve.
Strathdee in Context: Comparative Approaches to National Coordination
To inform her reasoning in Strathdee, Justice Leiper undertook a broad review of national coordination jurisprudence, including decisions that have both stayed duplicative proceedings and permitted overlapping class actions to proceed. Viewed alongside other national coordination decisions, Strathdee fits within a line of authority that resists rigid priority rules and instead turns on differences in class and legal scope, the practical consequences of duplication and whether parallel proceedings materially advance or undermine the purposes of the class proceedings regime.
Although not addressed in Strathdee, similar national coordination issues arose in Underhill v. Medtronic Canada, 2023 ONSC 5919, where Justice Agarwal adjourned the plaintiff's motion to discontinue the Ontario action pending the resolution of the defendants' stay application in the parallel British Columbia action, citing, among other considerations, the risk of limitations prejudice to absent class members. In his reasons, Justice Agarwal emphasized that overlapping class actions and strategic litigation decisions by class counsel are an inherent feature of Canada's multi-jurisdictional class action regime, and do not, without more, constitute an abuse of process. Medtronic similarly highlighted the importance of coordination and case management in addressing parallel class proceedings.
By contrast, other national coordination decisions have reached different outcomes where the parallel proceedings involved a more substantial degree of overlap and lacked the material distinctions that Justice Leiper found in Strathdee. One such example is Winder v. Marriott International Inc., 2019 ONSC 5766, which Justice Leiper referred to in her preferability analysis. In Winder, Justice Perell addressed the challenges posed by overlapping national class actions in the context of a carriage motion arising from the Marriott data breach litigation. Although many of the traditional carriage factors were neutral, Justice Perell placed significant weight on the interrelationship between competing actions across jurisdictions. Justice Perell criticized the class counsel consortium strategy of pursuing overlapping proceedings in multiple provinces where it risked inefficiency and waste of judicial resources. By contrast, Siskinds' proposed approach of advancing a single national class action in Ontario was viewed as more consistent with principles of judicial economy and avoided unnecessary duplication.
If you have further questions about this update or life sciences issues more generally, please contact the authors or a member of the Life Sciences Group.
