Wells Fargo analyst David Maris says the dozens of doctors he spoke to about Valeant Pharmaceuticals' Siliq are not optimistic. Over 50% of the physicians surveyed said they would use Siliq only as a fourth line therapy or later, Maris tells investors in a research note after Valeant announced the launch of the moderate-to-severe plaque psoriasis treatment. The analyst disagrees with Valeant management's claims that Siliq has "very large peak sales potential." The injection carries a warning about risk of suicide and Valeant will be competing against a large number of peers with greater resources, Maris argues. The analyst has an Underperform rating on Valeant shares, which are down 18c to $17.59 in midday trading.