This is a single-arm, open-label, multicenter, non-indication seeking phase II trial to describe the efficacy and safety of patients with mantle cell lymphoma (MCL) receiving acalabrutinib in combination with R-CHOP for the front-line treatment of MCL in Spain. Acalabrutinib will be administered until disease progression if medically appropriate, along with R-CHOP based on institutional standards. After 6 cycles of acalabrutinib in combination with R-CHOP, subjects who tolerate treatment and not progressing, will then receive monotherapy acalabrutinib. In addition, subjects who achieve a response (PR or greater) will receive maintenance rituximab every other 28-day cycle for a maximum of 12 additional doses. Thereafter, subjects receive monotherapy acalabrutinib until disease progression or treatment discontinuation.