The so-called "concerned shareholders," led by former Biovail Corp. executives William Wells and Greg Gubitz, have announced an August meeting date.
But Bioniche says the company has already set a meeting date for Nov. 5.
The company also says the dissidents have launched court proceedings against Bioniche to try to force an earlier date, with a court date set for July 18.
Announcing an August meeting shows "total disregard" for the court process, Bioniche says.
The dissident shareholders are seeking to replace the company's board of directors. They have accused management of failing to deliver on past promises in the face of a steady decline in the company's business.
Bioniche has already rejected two requests for meetings by the dissident shareholders.
The company researches, develops, manufactures and commercializes health products used to treat humans and animals.