This study focuses on people with a type of cancer called B-cell Non-Hodgkin Lymphoma that has not improved with previous treatments. The main goal is to see if a new medicine, Loncastuximab Tesirine, is safe and effective when combined with other cancer medicines, such as Polatuzumab Vedotin, Glofitamab, or Mosunetuzumab. Participants will go through different phases, including a screening period of up to 28 days, treatment cycles every 21 days, and follow-up visits every 12 weeks for up to two years.

Loncastuximab Tesirine is an antibody drug conjugate (ADC), which means it combines an antibody (a protein that targets cancer cells) with a drug that kills those cells. This study will help find the best dose and check for any side effects.

• Participants need to be 18 years or older and have a life expectancy of at least 24 weeks.
• The study lasts up to one year, with regular visits and checks.
• Participants should not have had certain treatments like stem cell transplants recently.