london, dec 17 (reuters) - glaxosmithkline plc's (gsk.l: quote
) cervical cancer vaccine cervarix faces a delay in winning approval in the united states, putting it further behind merck & co inc's (mrk.n: quote
) rival product gardasil.
glaxo, europe's biggest drugmaker, said on monday it had received a "complete response letter" from the u.s. food and drug administration (fda), which is issued when the regulator has completed the review of a medicine, but still has questions.
analysts, who had been expecting the fda to issue a decision on cervarix by next month, said the setback would delay approval by at least a few months and potentially more than a year if additional clinical data is needed.