Primary Objective:

To evaluate objective response rate (ORR) in adult patients with relapsed/refractory follicular lymphoma (r/r FL) grade 1-3a who are treated with currently available therapies in the real-world setting according to Lugano classification (Cheson, 2014) of malignant lymphoma and as assessed by independent central review.

Secondary Objectives:

To evaluate the following outcomes in adult patients with r/r FL grade 1-3a who are treated with currently available systemic therapies in the real-world setting:

1. Objective response rate (ORR) according to the Lugano classification and as assessed by treating physician evaluation

2. Complete response (CR) rate according to the Lugano classification and as assessed by:

   • Independent central review, and
   • Treating physician evaluation

3. Progression-free survival (PFS) according to the Lugano classification and as assessed by:

   • Independent central review, and
   • Treating physician evaluation

4. Overall survival (OS)

5. Duration of response (DOR) according to the Lugano classification and as assessed by:

   • Independent central review, and
   • Treating physician evaluation

6. Disease control rate (DCR) according to the Lugano classification and as assessed by:

   • Independent central review, and
   • Treating physician evaluation

7. Time to next treatment (TTNT)

8. Histological transformation (HT)

Key Inclusion Criteria:

1. Have a histologically confirmed diagnosis of FL grade1-3a as defined in the protocol
2. Have been r/r to at least 2 lines of systemic therapy for FL grade 1-3a, including an anti-CD20 antibody and an alkylating agent as defined in the protocol
3. Have initiated at least one additional line of systemic therapy (salvage therapy) for FL grade 1-3a between 01 Jan 2015 and 31 Dec 2020 (indexing period) after meeting the criteria for r/r FL grade 1-3a as described above; the first additional line of systemic therapy during the indexing period that meets all of the remaining inclusion and exclusion criteria defined below will be the participants' first qualifying salvage therapy
4. Have measurable disease on cross sectional imaging (defined as at least 1 bi-dimensionally measurable nodal lesion ≥1.5 centimeter [cm] in the greatest transverse diameter [GTD] regardless of the short axis diameter) documented by diagnostic imaging (computed tomography [CT], or magnetic resonance imaging [MRI]) recorded on or during the 8 weeks prior to index date
5. Have FL treatment response assessed according to Lugano classification of malignant lymphoma or are deceased prior to opportunity for assessment

Key Exclusion Criteria:

1. Evidence of histological transformation (HT) prior to index date (ie, evolution to a clinically aggressive non-hodgkin's lymphoma (NHL) such as diffuse large B-Cell lymphoma (DLBCL) as defined in the protocol
2. Primary central nervous system (CNS) lymphoma or known involvement by non-primary CNS non-Hodgkin's lymphoma (NHL) on or prior to index date
3. History of allo-stem cell transplant (SCT) prior to index date
4. Received anti-CD20 x anti-CD3 bispecific therapy prior to index date
5. Another malignancy in the 5 years on or prior to index date, with the exception of non-melanoma skin cancer and B-NHL
6. History of neurodegenerative condition or CNS movement disorder on or prior to index date
7. Evidence of significant cardiovascular disease on or prior to index date
8. Evidence of significant pulmonary disease, defined as obstructive pulmonary disease and a history of symptomatic bronchospasm on or prior to index date.
9. Eastern Cooperative Oncology Group (ECOG) performance status >1 on or prior to index date.
10. Inadequate organ function as defined in the protocol

Note: Other protocol-defined Inclusion/Exclusion criteria apply

Adult participants with FL grade1-3a who have relapsed after or are refractory to at least 2 prior lines of systemic therapy, including an anti-CD20 antibody and an alkylating agent.