A Randomized, Double-blind, Multi-center, Multi-national Trial to Evaluate the Efficacy, Safety, and Immunogenicity of SAIT101 Versus Rituximab as a First-line Immunotherapy Treatment in Patients With Low Tumor Burden Follicular Lymphoma

This is a Randomized, Double-blind, Multi-center, Multi-national Trial to Evaluate the statistical equivalence of efficacy, safety and immunogenicity of SAIT101 Versus Rituximab as a First-line Immunotherapy Treatment in asymptomatic patients with Low Tumor Burden Follicular Lymphoma.

This is a Randomized, Double-blind, Multi-center, Multi-national Trial to Evaluate the statistical equivalence of efficacy, safety and immunogenicity of SAIT101 Versus Rituximab as a First-line Immunotherapy Treatment in asymptomatic patients with Low Tumor Burden Follicular Lymphoma. Patients will be randomized in a 1:1 ratio to receive study drug once a week for 4 weeks, and will then be followed up for up to 52 weeks after the first dose. Randomization will be stratified by inclusion in the PK/PD sub-population and Follicular lymphoma international prognostic index 2 (FLIPI-2) score.

Visits are scheduled at Weeks 1, 2, 3, and 4 (study drug infusion visits), and then at Weeks 5, 12, 20, 28, 36, and 52 (i.e., End of Study \[EOS\]). Efficacy response assessments will be performed at Weeks 12 and 28, while safety assessments will continue until end of Study (EOS).

The primary objectives is to compare the efficacy of SAIT101 with rituximab licensed in the European Union (hereafter designated MabThera®, brand name in EU) when administered as a first-line immunotherapy in patients with low tumor burden follicular lymphoma (LTBFL) and the secondary objectives is to evaluate SAIT101 versus MabThera® with respect to safety and tolerability, immunogenicity and Pharmacokinetics (PK)/Pharmacodynamics (PD) in a sub-population of patients.

Eligibility Criteria:
Inclusion Criteria:

1. Patients with histologically-confirmed Low Tumor Burden Follicular Lymphoma, without B symptoms, Ann Arbor stage II to Non-Hodgkin's Lymphoma (NHL) (CD20+ Follicular Lymphoma of Grades 1, 2, or 3a)
2. Low tumor burden according to The Groupe d'Etude des Lymphomes Folliculaires (GELF) criteria defined as:

   * Normal serum lactate dehydrogenase (LDH)
   * No mass ≥7 cm.
   * Less than 3 nodal sites, each with diameter \>3 cm
   * No systemic or B symptoms (fever \>38°C for 3 consecutive days; recurrent, drenching night sweats; unintentional weight loss exceeding 10% body weight in the last 6 months.
   * No splenomegaly ≥16 cm by CT scan.
   * No risk of vital organ compression.
   * No pleural or peritoneal serous effusion.
   * No leukemic phase \>5,000/µL circulating tumor cells.
   * No cytopenias (defined as platelets \<100,000/mm3, hemoglobin \<10 g/dL, or absolute neutrophil count \<1,500/mm3).
3. Patients not previously treated for their FL, including any previous treatment for FL under clinical trials except localized radiation therapy for previous limited stage disease.

Exclusion Criteria:

1. Previous treatment with any chemotherapy and/or rituximab or other monoclonal antibody.
2. Prior radiotherapy completed \<28 days before study enrollment.
3. Anticipated need for concomitant administration of any other experimental drug, or a concomitant chemotherapy, anticancer hormonal therapy, radiotherapy, or immunotherapy during study participation.
4. Concomitant disease which requires continuous therapy with corticosteroids at doses equivalent to prednisolone \>20 mg/day.
5. Transformation to high-grade lymphoma secondary to previously untreated low-grade lymphoma.
6. Prior or concomitant malignancies within 5 years prior to screening, with the exceptions of non-melanoma skin cancer, adequately treated carcinoma in situ of the cervix, adequately treated breast cancer in situ, and localized prostate cancer stage T1c, provided that the patient underwent curative treatment and remains relapse free.
7. Patients with a body surface area \>3.0 m2.
8. Major surgery (excluding lymph node biopsy) within 28 days prior to randomization.
9. Primary or secondary immunodeficiency (history of, or currently active), including known history of human immunodeficiency virus (HIV) infection or positive test at screening.
10. Acute, severe infection (e.g., sepsis and opportunistic infections), or active, chronic or persistent infection that might worsen with immunosuppressive treatment (e.g., herpes zoster).
11. Positive serological test for hepatitis B surface antigen (HBsAg), hepatitis B core antibody (HBcAb) or hepatitis C serology.
12. Confirmed current active tuberculosis (TB)
13. Central nervous system (CNS) or meningeal involvement, or cord compression by the lymphoma; history of CNS lymphoma
14. History of a severe allergic reaction or anaphylactic reaction to a biological agent or history of hypersensitivity to any component of the trial drug (e.g., hypersensitivity or allergy to murine products).
15. Patients who have significant cardiac disease, including but not limited to history of congestive heart failure (New York Heart Association Class III/IV; see Appendix 7), unstable angina, or uncontrolled cardiac arrhythmia.
16. Uncontrolled or severe hypertension, or cerebrovascular disease.
17. Serious underlying medical conditions that, per the Investigator's discretion, could impair the ability of the patient to participate in the trial
18. Any other co-existing medical or psychological condition(s) that will preclude participation in the study or compromise ability to give informed consent and/or comply with study procedures.
19. Treatment with any investigational medicinal product (IMP) within 4 weeks prior to initiation of 1st infusion of study drug, or treatment with a drug that has not received regulatory approval for any indication within 4 weeks or a minimum of 5 half-lives, whichever is longer, of the 1st infusion of study drug.
20. Receipt of a live/attenuated vaccine within 6 weeks prior to the screening visit.
21. Females who are pregnant, breastfeeding, or planning a pregnancy during the treatment period or within 12 months after the last infusion of study drug.
22. Patients who are investigational site staff members directly involved in the conduct of the trial, and their family members, site staff members otherwise supervised by the investigator, or patients who are Archigen employees directly involved in the conduct of the trial.