DOR: duration from date of initial documentation of response (PR/better) to date of first documented progressive disease(PD), death or date of censoring if applicable, for responders (PR/better), as assessed by investigator. VGPR/PR: >=90% reduction or normal serum IgM values (for VGPR) and >=50% (for PR) reduction of serum IgM, with reduction in lymphadenopathy/splenomegaly if present at baseline. PD(at least 1): >=25% IgM increase in serum IgM with >=500 milligrams per deciliters(mg/dL) increase from nadir(lowest serum IgM value at any time from baseline), confirmation needed if IgM was sole PD criterion; new lymph nodes >1.5 centimeters(cm), >=50% increase in nadir in sum of product of diameters; 50% increase in longest diameter of previously identified node >1cm in short axis; new splenomegaly; new extranodal disease; new/recurrent bone marrow involvement; new symptomatic disease(pleural effusion/Bing Neel syndrome/amyloidosis/light chain deposition/paraprotein mediated disorder).

TTR was defined as the time from the date of first dose to the date of initial documentation of a response (PR or better) for responders. PR: >=50% reduction of serum IgM from baseline, with reduction in lymphadenopathy/splenomegaly if present at baseline. VGPR: >=90% reduction of serum IgM from baseline or normal serum IgM values, with reduction in lymphadenopathy/splenomegaly if present at baseline.

PFS was defined as duration from the date of first dose to the date of disease progression or death, whichever occurs first, assessed according to the modified sixth IWWM (NCCN 2019) criteria. PD (at least 1 of the following): >=25% IgM increase in serum IgM with >=500 mg/dL increase from nadir (lowest serum IgM value at any time from baseline), confirmation needed if IgM was sole PD criterion; new lymph nodes >1.5 cm, >=50% increase in nadir in sum of product of diameters; 50% increase in longest diameter of previously identified node >1 cm in short axis; new splenomegaly; new extranodal disease; new/recurrent bone marrow involvement; new symptomatic disease (pleural effusion, Bing Neel syndrome, amyloidosis, light chain deposition, paraprotein mediated disorder).

Overall survival was measured from the date of first dose to the date of the participant's death from any cause.

An adverse event (AE) was any untoward medical occurrence in a clinical study participant administered a medicinal (investigational or non-investigational) product. An AE does not necessarily have a causal relationship with the intervention. TEAEs were defined as AEs occurring after the first dose of study drugs and within 30 days following the last dose of study drug or initiation of subsequent antineoplastic treatment, whichever occurred earlier. TEAEs were graded based on National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) Version 4.03 as Grade 1= Mild; Grade 2= Moderate; Grade 3= Severe; Grade 4= Life-threatening and Grade 5= Death. Number of participants with TEAEs and Grade 3 or higher TEAEs (included serious and non-serious events) were reported in this outcome measure.

Plasma concentrations of ibrutinib were reported.

CRR was defined as the percentage of participants who achieved minor response (MR) or better according to the modified sixth IWWM (NCCN 2019) criteria as assessed by the investigator. MR: >=25% but less than (<) 50% reduction of serum IgM from baseline.

All treated analysis set included all enrolled participants who received at least 1 dose of study drug.

VGPR or better response rate was defined as the percentage of participants who achieved VGPR or better according to the modified sixth IWWM (NCCN 2019) criteria as assessed by the investigator. VGPR: >=90% reduction of serum IgM from baseline or normal serum IgM values, with reduction in lymphadenopathy/splenomegaly if present at baseline.

All treated analysis set included all enrolled participants who received at least 1 dose of study drug.

DOR: duration from date of initial documentation of response (PR/better) to date of first documented progressive disease(PD), death or date of censoring if applicable, for responders (PR/better), as assessed by investigator. VGPR/PR: >=90% reduction or normal serum IgM values (for VGPR) and >=50% (for PR) reduction of serum IgM, with reduction in lymphadenopathy/splenomegaly if present at baseline. PD(at least 1): >=25% IgM increase in serum IgM with >=500 milligrams per deciliters(mg/dL) increase from nadir(lowest serum IgM value at any time from baseline), confirmation needed if IgM was sole PD criterion; new lymph nodes >1.5 centimeters(cm), >=50% increase in nadir in sum of product of diameters; 50% increase in longest diameter of previously identified node >1cm in short axis; new splenomegaly; new extranodal disease; new/recurrent bone marrow involvement; new symptomatic disease(pleural effusion/Bing Neel syndrome/amyloidosis/light chain deposition/paraprotein mediated disorder).

Analysis population included responders in all treated analysis set who achieved PR or better.

TTR was defined as the time from the date of first dose to the date of initial documentation of a response (PR or better) for responders. PR: >=50% reduction of serum IgM from baseline, with reduction in lymphadenopathy/splenomegaly if present at baseline. VGPR: >=90% reduction of serum IgM from baseline or normal serum IgM values, with reduction in lymphadenopathy/splenomegaly if present at baseline.

Analysis population included responders in all treated analysis set who achieved PR or better.

PFS was defined as duration from the date of first dose to the date of disease progression or death, whichever occurs first, assessed according to the modified sixth IWWM (NCCN 2019) criteria. PD (at least 1 of the following): >=25% IgM increase in serum IgM with >=500 mg/dL increase from nadir (lowest serum IgM value at any time from baseline), confirmation needed if IgM was sole PD criterion; new lymph nodes >1.5 cm, >=50% increase in nadir in sum of product of diameters; 50% increase in longest diameter of previously identified node >1 cm in short axis; new splenomegaly; new extranodal disease; new/recurrent bone marrow involvement; new symptomatic disease (pleural effusion, Bing Neel syndrome, amyloidosis, light chain deposition, paraprotein mediated disorder).

All treated analysis set included all enrolled participants who received at least 1 dose of study drug. Here, 'N' (overall number of participants analyzed) refers to the number of participants evaluable for this outcome measure.

Overall survival was measured from the date of first dose to the date of the participant's death from any cause.

All treated analysis set included all enrolled participants who received at least 1 dose of study drug.

An adverse event (AE) was any untoward medical occurrence in a clinical study participant administered a medicinal (investigational or non-investigational) product. An AE does not necessarily have a causal relationship with the intervention. TEAEs were defined as AEs occurring after the first dose of study drugs and within 30 days following the last dose of study drug or initiation of subsequent antineoplastic treatment, whichever occurred earlier. TEAEs were graded based on National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) Version 4.03 as Grade 1= Mild; Grade 2= Moderate; Grade 3= Severe; Grade 4= Life-threatening and Grade 5= Death. Number of participants with TEAEs and Grade 3 or higher TEAEs (included serious and non-serious events) were reported in this outcome measure.

Safety analysis set included all enrolled participants who received at least 1 dose of study drug.

Plasma concentrations of ibrutinib were reported.

Pharmacokinetics (PK) evaluable analysis set included all enrolled participants who received at least 1 dose of ibrutinib and had at least 1 available PK sample after treatment. Here, 'n' (number analyzed) signifies number of participants evaluable for specified time point.