A Phase II Randomized Study Comparing the Efficacy and Safety of Targeted Therapy or Cancer Immunotherapy Versus Platinum-Based Chemotherapy in Patients With Cancer of Unknown Primary Site

This study will compare the efficacy and safety of molecularly-guided therapy versus standard platinum-containing chemotherapy in participants with poor-prognosis cancer of unknown primary site (CUP; non-specific subset) who have achieved disease control after 3 cycles of first-line platinum based induction chemotherapy.


Eligibility Criteria:
Inclusion Criteria:

* Histologically-confirmed unresectable cancer of unknown primary site (CUP) diagnosed according to criteria defined in the 2015 European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for CUP
* No prior lines of systemic therapy for the treatment of CUP
* Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
* Candidate for platinum-based chemotherapy (according to the reference information for the intended chemotherapy)
* At least one measurable lesion according to Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST v1.1)
* Formalin-Fixed Paraffin-Embedded (FFPE) tumor tissue sample \</= 4 months old that is expected to be sufficient for generation of a comprehensive genomic profile at a central reference pathology laboratory

Exclusion Criteria:

* Squamous cell CUP
* Participants who can be assigned to a specific subset of CUP for which a specific treatment is recommended by the 2015 ESMO Clinical Practice Guidelines for CUP or with a clinical and IHC profile indicative of a specific primary tumor (favorable prognosis CUP subsets): Poorly differentiated carcinoma with midline distribution; women with papillary adenocarcinoma of the peritoneal cavity; women with adenocarcinoma involving only the axillary lymph nodes; squamous cell carcinoma of the cervical lymph nodes; poorly differentiated neuroendocrine tumors; men with blastic bone metastases and elevated prostate-specific antigen (PSA); participants with a single, small, potentially resectable tumor; colon cancer-type CUP, including participants with a CK7 negative, CK20 positive, CDX-2 positive immunohistochemistry profile; CK7-positive, CK20-negative and TTF-1 positive tumors in a context suggestive of lung adenocarcinoma or thyroid cancer; IHC profile definitely indicative of breast cancer OR an IHC profile indicative of breast cancer and either a history of breast cancer or lymph nodes in the drainage areas of the breast; high-grade serious carcinoma histology and elevated CA125 tumor marker and/or a mass in the gynecological tract or any tumor mass or lymph node in the abdominal cavity; IHC profile suggestive of renal cell carcinoma and renal lesions, with a Bosniak classification higher than IIF; IHC profile compatible with cholangiocarcinoma or pancreatobiliary (or upper gastrointestinal carcinoma) AND 1 or 2 liver lesions without extrahepatic disease or with only pulmonary metastases and/or lymph nodes in the drainage areas of the liver
* Known presence of brain or spinal cord metastasis (including metastases that have been irradiated only)
* Histology and immunohistology profiles (per 2015 ESMO guidelines) that are not adenocarcinoma or poorly differentiated carcinoma/adenocarcinoma
* History or known presence of leptomeningeal disease
* Known human immunodeficiency virus (HIV) infection
* Significant cardiovascular disease
* Prior allogeneic stem cell or solid organ transplantation
* Pregnancy or breastfeeding, or intention of becoming pregnant during study treatment or for up to 7 months after the final dose of treatment