A Phase 2 Study Evaluating the Efficacy and Safety of DKN-01 as a Monotherapy or in Combination With Paclitaxel in Patients With Recurrent Epithelial Endometrial, Epithelial Ovarian Cancer, or Carcinosarcoma

• Diagnosis:

∙ Epithelial Endometrial Cancer: histologically confirmed diagnosis (by either primary surgical specimen or biopsy for recurrence) of recurrent previously treated EEC.

‣ Epithelial Ovarian Cancer: histologically confirmed diagnosis (by either primary surgical specimen or biopsy for recurrence) of recurrent platinum-resistant/refractory EOC, primary peritoneal, or fallopian tube cancer (i.e., disease recurrence within 6 months of completion of or progression during platinum-based chemotherapy).

‣ Carcinosarcoma/Malignant Mixed Mullerian Tumors: histologically confirmed diagnosis (by either primary surgical specimen or biopsy for recurrence) of recurrent uterine or ovarian carcinosarcoma (MMMT). Patients must have had only 1 prior chemotherapeutic regimen for management of carcinosarcoma that may have been included chemotherapy (including in adjuvant setting), chemotherapy and radiotherapy, and/or consolidation/maintenance therapy.

• Refractory or intolerant to at least one prior standard therapy(ies) for metastatic or locally advanced disease (see Inclusion Criterion #1c for Groups 5-6).

∙ If prior therapy consisted of palliative chemoradiation therapy, it will be considered one line of therapy.

‣ Prior treatment with paclitaxel as part of definitive therapy regimen is acceptable, provided the patient is not intolerant of paclitaxel.

‣ Patients who are not eligible to receive paclitaxel will be allowed to receive single agent DKN-01.

• Tumor tissue for mandatory pre-treatment and on-treatment biopsies.

• One or more tumors measurable on radiographic imaging as defined by RECIST 1.1.

• Ambulatory and ≥18 years of age.

• ECOG performance status (PS) of 0 or 1

• a. ECOG PS of 2 may be eligible upon the review and approval of the Medical Monitor.

• Estimated life expectancy of at least 3 months, in the judgment of the Investigator.

• Disease-free of active second/secondary or prior malignancies for ≥2 years with the exception of currently treated basal cell, squamous cell carcinoma of the skin, or carcinoma in-situ of the cervix or breast.

• Acceptable liver, renal, hematologic and coagulation function

⁃ Females of child bearing potential and male partners of female patients must agree to use adequate contraception during the study and for 6 months after their last dose of study drug.

⁃ Reliable and willing to make themselves available for the duration of the study and are willing to follow study-specific procedures.

⁃ Provided written informed consent prior to any study-specific procedures.