Striking a more reflective tone and pledging to listen to critics, Valeant Pharmaceuticals International Inc. Chief Executive Officer Mike Pearson sought to regain confidence from investors in remarks that painted a fuller picture of the drugmaker's financial exposure to a controversial pharmacy partner. In his first public comments since Valeant said it would cut ties with Philidor Rx Services, Pearson warned that the impact of the decision would meaningfully affect the dermatology business, which makes up almost a fifth of total revenue.