Toronto, March 16: Canada's main stock market in Toronto fell elusive as weaker commodity prices weighed on energy and mining stocks, while shares of a major drug maker tanked. The Toronto Stock Exchange's benchmark Standard & Poor's/TSX Composite Index lost 77.23 points, or 0.57 percent, to close at 13,400.31 points on Tuesday, Xinhua news agency reported. Six of the TSX index's eight main sub-sectors ended lower. Health care sector was rattled by 11.69 percent, as Valeant Pharmaceuticals International Inc. plunged 50.71 percent to 45.14 Canadian dollars after it cut its 2016 revenue forecast by about 12 percent and said a delay in filing its annual report could pose a debt default risk. GeneNews Limited was down 17.30 percent as well to 0.095 Canadian dollar as the Markham, Ontario-based molecular diagnostics company, announced Monday that it intends to sell up to 5 million Canadian dollars ($3.8 million) in common stock through an unbrokered private placement. The Canadian dollar was traded lower at $0.7484, compared with Monday's closing rate of $0.7537.