It is a phase II, multicenter, open-label study is to evaluate the safety, efficacy and pharmacokinetics of a novel BTK inhibitor, ICP-022, in approximately 85 subjects with R/R DLBCL. There will be no control group in this study. Each subject will receive treatment orally every day in 28-day cycles. Each cycle starts immediately after the previously completed cycle without a break between cycles.

Key Inclusion criteria：

1. Men and women between 18 and 75 years old,
2. Histologically confirmed diffuse large B-cell lymphoma（DLBCL）with MyD88 L265P and CD79B positive, at least one measurable tumor of greater than 1.5 centimeter in long axis by contrast-enhanced CT/MRI,
3. ECOG performance status of 0-2,
4. Voluntary written informed consent prior to trail screening.

Key Exclusion criteria:

1. History of other active malignancies, unless cured without evidence of relapse or metastasis within 5 years of study entry
2. History of Richter's syndrome
3. Current or history of lymphoma involved central nervous system
4. Prior corticosteroids (at dosages equivalent to prednisone > 20 mg/day) given with anti-neoplastic intent within 7 days, prior chemotherapy, targeted therapy, radiation therapy, or antibody based therapies or anti-cancer TCM within 4 weeks of the start of study drug.
5. The investigator considers other conditions unsuitable for this study.

Note: Other protocol defined Inclusion/Exclusion criteria may apply.