13. Tumor site accessible for both pre-treatment and post-treatment biopsies will be required for a minimum of 67% of study participants in each dose cohort where "n" is at least 3. In PART ONE of the study the first cohort-dose level 0, (who will receive hydroxyurea plus zero mg of SCH900776) is unique in that all participants in this cohort will be required to have biopsiable tumor sites.