A Phase 3, Randomized, Double-Blind, Placebo-Controlled, Multicenter Study to Evaluate the Efficacy and Safety of Tafasitamab Plus Lenalidomide in Addition to Rituximab Versus Lenalidomide in Addition to Rituximab in Patients With Relapsed/Refractory (R/R) Follicular Lymphoma Grade 1 to
3a or R/R Marginal Zone Lymphoma

Follicular lymphoma and marginal zone lymphoma are malignant disease of
B-lymphocytes and the most common indolent NHL subtypes. Both subtypes are
considered incurable as patients usually respond to initial therapy but
typically relapse over time. This study investigates tafasitamab which is a
monoclonal antibody against CD19, a protein expressed on the surface of normal
and malignant B-lymphocytes. By targeting CD19, tafasitamab is thought to help
the immune system to destroy the lymphoma cells. The combination of
tafasitamab, rituximab and lenalidomide may result in an enhanced, synergistic
immune response against lymphoma cells.

This study has been transitioned to CTIS with ID 2023-504684-16-00 check the CTIS register for the current data.

This study compares the efficacy of tafasitamab + lenalidomide + rituximab to
the efficacy of placebo + lenalidomide + rituximab in terms of progression-free
survival (PFS) in participants with R/R follicular lymphoma. In addition, the
efficacy of tafasitamab + lenalidomide + rituximab is compared to the efficacy
of placebo + lenalidomide + rituximab in terms of PFS in the overall population
(FL and MZL), and in terms of PET-CR rate in FDG-avid FL participants and
overall survival (OS) in the FL population.

This is a Phase 3, multicenter, randomized, double-blind, placebo-controlled,
2-arm study that is designed to evaluate the efficacy and safety of tafasitamab
+ lenalidomide + rituximab vs placebo + lenalidomide + rituximab in
participants with R/R FL or MZL. Approximately 528 participants with FL and 60
to 90 participants with MZL will be randomized at a 1:1 ratio to the 2
treatment groups. An independent data monitoring committee (IDMC) will review
the safety data after the first 60 participants have completed 2cycles of study
treatment to monitor and evaluate the safety of the combination treatment. An
interim analysis for futility will be performed at approximately 20%
information rate (35 PFS events) in the FL population.

Participants will be treated with the study drug combination for up to 1 year,
in 12 cycles of 28 days length. Participants will be divided into two treatment
groups:

Treatment Group A:
• Tafasitamab (12 mg/kg IV), 28-day cycle
- Cycles 1 to 3: Days 1, 8, 15, and 22
- Cycles 4 to 12: Days 1 and 15
• Rituximab (including biosimilars; 375 mg/m2 IV), 28-day cycle
- Cycle 1: Days 1, 8, 15, and 22
- Cycles 2 to 5: Day 1
• Lenalidomide (including generics; 20 mg PO once daily), 28-day cycle
- Cycles 1 to 2: Days 1 to 21

Treatment Group B:
• Tafasitamab placebo (0.9% saline solution) IV, 28-day cycle
- Cycles 1 to 3: Days 1, 8, 15, and 22
- Cycles 4 to 12: Days 1 and 15
• Rituximab (including biosimilars; 375 mg/m2 IV), 28-day cycle
- Cycle 1: Days 1, 8, 15, and 22
- Cycles 2 to 5: Day 1
• Lenalidomide (including generics; 20 mg PO once daily), 28-day cycle
- Cycles 1 to 12: Days 1 to 21

The Participant's participation in this study will last about 8 years
(treatment period of 1 year) and the particpant will visit the hospital
approximately 30 times during this period. Each visit will take between 4 - 8
hours to complete. The study will consist of a screening, treatment, follow-up
and long term follow-up period.

The following tests and procedures will take place during the hospital visits
- Physical exam (including body weight and height), vital signs
- Review the ability to perform daily activities and symptoms associated with
lymphoma
- Questionnaires
- Pregnancy tests in women of childbearing potential
- Blood and urine samples
- Biopsy
- CT / MRI scan
- PET scan
- ECHO/MUGA
- ECG

Please refer to page 19-23 of the protocol (schedule of events) for more
information.

Possible side effects that are already known are described in the
Investigator's Brochure and in paragraph 6 and appendix D of the subject
informed consent form.