I. To evaluate the ability of AZD1775 to inhibit Wee1 and increase deoxyribonucleic acid (DNA) damage and tumor cell death when combined with nab-paclitaxel/gemcitabine compared to nab-paclitaxel/gemcitabine/placebo. (Phase II) II. To evaluate if biomarker changes in tumor tissue associated with Wee1 inhibition may also be present in hair follicles. (Phase II) III. To evaluate the change in tumor fludeoxyglucose (FDG) uptake (maximum standardized uptake value [SUVmax]) between baseline FDG-positron emission tomography (PET) and week 4 FDG-PET as a predictor of response using Response Evaluation Criteria in Solid Tumors (RECIST) as the reference standard for response. (Phase II) IV. To evaluate the change in tumor FDG uptake (SUVmax) between baseline FDG-PET and week 4 FDG-PET as a predictor of progression-free survival. (Phase II) V. To compare the change in tumor FDG uptake (SUVmax) between baseline FDG-PET and week 4 FDG-PET between the patients from treatment arms C and D. (Phase II) VI. To evaluate if an early increase in tumor fluorothymidine (FLT) uptake (FLT-flare) is observed within 24 hours after initiation of treatment with nab-paclitaxel/gemcitabine/placebo. (Phase II) VII. To evaluate if an early (within 24 hours [h]) increase in tumor FLT uptake (FLT-flare) is abrogated after initiation of treatment with nab-paclitaxel/gemcitabine/AZD1775. (Phase II) VIII. To compare the change in tumor FLT uptake (SUVmax) from baseline to 24 hours after initiation of treatment between the patients from treatment arms C and D. (Phase II)