This study is evaluating the experimental drug EZM0414 for people with multiple myeloma (MM) or diffuse large B-cell lymphoma (DLBCL) that has recurred after previous treatment or has not responded to previous treatment.

Experimental means that EZM0414 has not yet been approved by the United States Food and Drug Administration (FDA).

EZM0414 targets and can halt certain cancer cell growth by stopping a protein called SETD2 from working. Studies like this one help us to understand more about whether EZM0414 will be a safe and effective study drug for patients with different types of cancers.

Participants will take EZM0414 orally every day in 28-day cycles. The study team will determine the dosing schedule and appropriate dose increases throughout the study.

Total study participation depends on how each participant responds to the study drug and how long they are benefiting from it. Participants will come into the office for study visits during each cycle to receive the medication as well as for some blood draws and other tests.