A Phase 1 First in Human Study of ARV-393 in Adult Participants with Advanced Non-Hodgkins Lymphoma.

Inclusion Criteria: - Eligible participants aged ≥18 years. - Have relapsed/refractory mature B-cell non-Hodgkin lymphoma (NHL) and ≥2 prior systemic therapies, or histologically confirmed AITL that has recurred or progressed following institutional standard-of-care therapy. - Participants must also have ≥1 measurable lesion at study entry - Eastern Cooperative Oncology Group performance status of 0 or 1, - Freshly biopsied or archival tumor tissue available, - Participants with adequate organ function, - Participants must accept and follow pregnancy prevention guidance. Exclusion Criteria: - No prior allogeneic stem cell transplant or solid organ transplantation, Autologous stem cell transplant, must not have occurred ≤100 days, previous CAR T-cell therapy ≤60 days, radiotherapy ≤ 2 weeks, systemic anticancer treatment ≤ 5 half-lives or 4 weeks, prior to ARV-393 treatment initiation. - Participants must not have significant acute or chronic medical illness, including hypereosinophilic syndrome, active interstitial lung disease or pneumonitis, active or uncontrolled infection, or the presence of laboratory abnormalities, that places participants at unacceptable risk if participating in this study. - Participants with an inability to comply with listed prohibited treatments.