PRIMARY OBJECTIVE:

I. To evaluate the efficacy of acalabrutinib combined with rituximab and lenalidomide in patients with previously untreated follicular lymphoma (FL) (determined by complete remission [CR] rate by the end of treatment).

SECONDARY OBJECTIVES:

I. To evaluate the efficacy of acalabrutinib combined with rituximab and lenalidomide in subjects with FL as assessed by objective response rate (ORR) at the end of treatment, duration of response (DOR), progression rate within 24 months from treatment initiation (progression-free survival [PFS] 24), PFS and overall survival (OS).

II. To evaluate the safety and tolerability of acalabrutinib combined with rituximab and lenalidomide in previously untreated subjects with FL.

EXPLORATORY OBJECTIVE:

I. To determine the pharmacodynamic effects and investigate biomarkers of response and resistance of the 3-drug combination.

Patients receive acalabrutinib orally (PO) twice daily (BID) on days 1-28. Beginning cycle 2, patients receive lenalidomide PO once daily (QD) on days 1-21 and rituximab intravenously (IV) on days 1, 8, 15, and 22 of cycle 2 and day 1 of subsequent cycles. Treatment repeats every 28 days for 13 cycles in the absence of disease progression or unacceptable toxicity.

After completion of study treatment, patients are followed up every 3 months for 1 year and then every 6 months for 2 years.