Researchers are looking for new ways to treat follicular lymphoma (FL). A standard (usual) treatment for FL includes a targeted therapy called rituximab and chemotherapy. In this study, researchers want to learn if giving a study medicine called MK-1045 and rituximab can treat FL. MK-1045 is a type of treatment called immunotherapy.
The goals of this study are to learn:
* About the safety of MK-1045 and rituximab, and if people tolerate them when given together
* If people who receive MK-1045 and rituximab have the cancer go away
* If people who receive MK-1045 and rituximab live longer without their cancer getting worse compared to those who receive standard treatment (rituximab and chemotherapy)