This study is evaluating how safe, tolerable and effective a new drug (called GEN3017) is when given to people with relapsed or refractory CD30-expressing lymphomasA Phase 1/2a, Open-Label, Dose Escalation Trial of GEN3017 With Expansion Cohorts in Relapsed or Refractory CD30+ Classical Hodgkin Lymphoma and CD30+ Non-Hodgkin Lymphoma

Exclusion

1. Primary central nervous system (CNS) tumor or known CNS involvement.
2. Received prior investigational CD30-targeting therapy (except brentuximab vedotin).
3. Autologous hematopoietic stem cell transplant (HSCT) within 60 days (applies to both cHL and TCL). Allogeneic HSCT within 90 days (applies to cHL) prior to the first dose of GEN3017.
4. Chemotherapy within 2 weeks or major surgery within 4 weeks prior to the first dose of GEN3017.
5. Curative radiotherapy within 4 weeks or palliative radiotherapy within 2 weeks prior to the first dose of GEN3017.
6. Treatment with an investigational drug within 4 weeks or 5 half-lives of the drug, whichever is shorter prior to the first dose of GEN3017 or currently receiving any other investigational agents.
7. Prior treatment with live, attenuated vaccines within 30 days prior to the first dose of GEN3017.
8. Receiving immunosuppressive drugs or systemic corticosteroids such as prednisone at doses >25 milligrams (mg) daily or its equivalent within 14 days prior to the first dose of GEN3017.

NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.