This phase III trial compares the effect of continuation of treatment with pembrolizumab (usual approach) to observation only at preventing cancer from coming back in patients with early-stage triple-negative breast cancer (TNBC) who achieved a pathologic complete response after preoperative chemotherapy in combination with pembrolizumab. The usual approach for patients with early-stage TNBC who receive preoperative chemotherapy plus pembrolizumab is to continue to receive pembrolizumab for up to 27 weeks after surgery. Immunotherapy with monoclonal antibodies, such as pembrolizumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. This trial may help researchers determine if observation is as good as receiving pembrolizumab for 27 weeks after surgery in triple-negative breast cancer patients who achieved a pathologic complete response after preoperative treatment with chemotherapy and pembrolizumab.

This phase II trial studies whether adding pembrolizumab to olaparib (standard of care) works better than olaparib alone in treating patients with pancreatic cancer with germline BRCA1 or BRCA2 mutations that has spread to other places in the body (metastatic). BRCA1 and BRCA2 are human genes that produce tumor suppressor proteins. These proteins help repair damaged deoxyribonucleic acid (DNA) and, therefore, play a role in ensuring the stability of each cells genetic material. When either of these genes is mutated, or altered, such that its protein product is not made or does not function correctly, DNA damage may not be repaired properly. As a result, cells are more likely to develop additional genetic alterations that can lead to some types of cancer, including pancreatic cancer. Immunotherapy with monoclonal antibodies, such as pembrolizumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Olaparib is an inhibitor of PARP, a protein that helps repair damaged DNA. Blocking PARP may help keep tumor cells from repairing their damaged DNA, causing them to die. PARP inhibitors are a type of targeted therapy. The addition of pembrolizumab to the usual treatment of olaparib may help to shrink tumors in patients with metastatic pancreatic cancer with BRCA1 or BRCA2 mutations.

This phase III trial uses the Decipher risk score to guide therapy selection. Decipher score is based on the activity of 22 genes in prostate tumor and may predict how likely it is for recurrent prostate cancer to spread (metastasize) to other parts of the body. Decipher score in this study is used for patient selection and the two variations of treatment to be studied: intensification for higher Decipher score or de-intensification for low Decipher score. Patients with higher Decipher risk score will be assigned to the part of the study that compares the use of 6 months of the usual treatment (hormone therapy and radiation treatment) to the use of darolutamide plus the usual treatment (intensification). The purpose of this section of the study is to determine whether the additional drug can reduce the chance of cancer coming back and spreading in patients with higher Decipher score. The addition of darolutamide to the usual treatment may better control the cancer and prevent it from spreading. Alternatively, patients with low Decipher risk score will be assigned to the part of the study that compares the use of radiation treatment alone (de-intensification) to the usual approach (6 months of hormone therapy plus radiation). The purpose of this part of the study is to determine if radiation treatment alone is as effective compared to the usual treatment without affecting the chance of tumor coming back in patients with low Decipher score prostate cancer. Radiation therapy uses high energy to kill tumor cells and reduce the tumor size. Hormone therapy drugs such as darolutamide suppress or block the production or action of male hormones that play role in prostate cancer development. Effect of radiation treatment alone in patients with low Decipher score prostate cancer could be the same as the usual approach in stabilizing prostate cancer and preventing it from spreading, while avoiding the side effects associated with hormonal therapy.

This phase I/Ib trial identifies the side effects and best dose of abemaciclib when given together with olaparib in treating patients with ovarian cancer that responds at first to treatment with drugs that contain the metal platinum but then comes back within a certain period (recurrent platinum-resistant). Abemaciclib may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Olaparib is an inhibitor of PARP, an enzyme that helps repair deoxyribonucleic acid (DNA) when it becomes damaged. Blocking PARP may help keep tumor cells from repairing their damaged DNA, causing them to die. PARP inhibitors are a type of targeted therapy. Adding abemaciclib to olaparib may work better to treat recurrent platinum-resistant ovarian cancer.

This phase II trial studies how well TPIV100 and sargramostim work in treating patients with HER2 positive, stage I-III breast cancer that has residual disease after chemotherapy prior to surgery. It also studies why some HER2 positive breast cancer patients respond better to chemotherapy in combination with trastuzumab and pertuzumab. TPIV100 is a type of vaccine made from HER2 peptide that may help the body build an effective immune response to kill tumor cells that express HER2. Sargramostim increases the number of white blood cells in the body following chemotherapy for certain types of cancer and is used to alert the immune system. It is not yet known if TPIV100 and sargramostim will work better in treating patients with HER2 positive, stage I-III breast cancer.

This phase I trial tests the safety, side effects, and best dose of ZEN003694 in combination with the usual treatment with capecitabine in treating patients with cancer that has spread from where it first started (primary site) to other places in the body (metastatic) or cannot be removed by surgery (unresectable) and that it has progressed on previous standard treatment. ZEN003694 is an inhibitor of a family of proteins called the bromodomain and extra-terminal (BET). It may prevent the growth of tumor cells that over produce BET protein. Capecitabine is in a class of medications called antimetabolites. It is taken up by cancer cells and breaks down into fluorouracil, a substance that kills cancer cells. Giving ZEN003694 in combination with capecitabine may be safe in treating patients with metastatic or unresectable solid tumors.