- If a participant has had a biopsy of the target oral premalignant lesions (OPL) lesion(s) within 6 weeks prior to the screening visit and archival tissue is available and the participant agrees to have archival tissue used for histologic confirmation and biomarker analysis, then NO additional biopsies (of the OPL) need to be performed at the screening visit; the pre-screening biopsy must undergo centralized pathology review before the second stage of registration can be performed; if archival tissue is not available, a waiting period of 6 weeks from the time of the last biopsy must be observed before re-biopsy for study purposes