In Charlton v. Abbott Laboratories, Ltd., 2015 BCCA 26, the Court of Appeal for British Columbia overturned certification of a class action on behalf of all Canadian consumers of sibutramine, a weight-loss drug.

It was alleged that sibutramine increased the risk of cardiovascular events.

The Plaintiffs’ evidence on general causation was a trial that had demonstrated that sibutramine increased risks of cardiovascular events on patient with pre-existing cardiovascular disease.

However, evidence was adduced that sibutramine ought not be prescribed to patients with such pre-existing diseases. Therefore, the Appellants pleaded that there was no evidence that sibutramine causes or contributes to cardiovascular events among class members, i.e. patients for whom it should have been prescribed and to whom it was marketed.

The Court of Appeal accepted the argument that the Plaintiffs had failed to adduce some evidence of a workable methodology for how the proposed common issue of general causation could be resolved on a class-wide basis. The Court also accepted the argument that the remaining common issues were heavily dependent on the general causation common issue, and thus could not be resolved on a class-wide basis either.

Charlton is the first class action involving a prescription drug that has been denied certification in British Columbia. This case provides defendants with an important roadmap for how to defeat the certification of pharmaceutical class actions in common law provinces.