•	Additional follow-up in Phase 3 ASPEN trial continued to show clinically meaningful safety and tolerability advantages for zanubrutinib compared to ibrutinib and demonstrated favorable CR/VGPR rate

•	Three-year data from Phase 1/2 trial evaluating patients with WM receiving zanubrutinib treatment showed high overall response rate

•	Company to host investor conference call and webcast on ASCO clinical updates on Friday, May 29 at 8:00 p.m. ET

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•	At data cutoff of August 31, 2019, with 19.4 months median follow-up:

◦	The combined CR+VGPR rate as assessed by independent review committee (IRC) for the overall intent-to-treat population was 28.4% in the zanubrutinib arm and 19.2% in the ibrutinib arm (2-sided descriptive p=0.0921);

◦	The combined CR+VGPR rate as assessed by investigators for the overall intent-to-treat population was 28.4% in the zanubrutinib arm and 17.2% in the ibrutinib arm (2-sided descriptive p=0.0437);

◦	Most common grade ≥ 3 adverse events (≥5% in either arm) for zanubrutinib compared to ibrutinib included hypertension (6% vs. 11%), neutropenia (16% vs. 8%), pneumonia (1% vs. 7%), anemia (5% vs. 5%), and thrombocytopenia (5% vs. 3%);

◦	Categories of AEs of interest for BTK inhibitors for zanubrutinib compared to ibrutinib included atrial fibrillation/flutter of any grade (2.0% vs. 15.3%), bleeding of any grade (48.5% vs. 59.2%), major hemorrhage (5.9% vs. 9.2%), diarrhea (20.8% vs. 31.6%), hypertension (10.9% vs. 17.3%); neutropenia (29.7% vs. 13.3%), infection (66.3% vs. 67.3%), and second malignancy (11.9% vs. 11.2%);

◦	Despite higher rates of grade ≥ 3 neutropenia among AEs of interest in the zanubrutinib arm (19.8% vs. 8.2% for ibrutinib), rates of infection were similar in patients taking zanubrutinib and ibrutinib (all grades: 66.3% vs. 67.3%; grade ≥ 3: 17.8% vs. 19.4%); and

◦	In the zanubrutinib arm, four (4.0%) patients discontinued treatment due to AEs and one (1.0%) patient had an adverse event leading to death; in the ibrutinib arm, nine patients (9.2%) discontinued due to AEs and four (4.1%) patients had an adverse event leading to death.

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•	After an additional five-months of follow-up with a data cutoff of January 31, 2020, with 24.2 months median follow-up:

◦	CR+VGPR as assessed by investigator for zanubrutinib was 30.4% compared to 18.2% for ibrutinib (exploratory analysis; 2-sided descriptive p=0.0302);

◦	Categories of AEs of interest for BTK inhibitors for zanubrutinib compared to ibrutinib included atrial fibrillation/flutter of any grade (3.0% vs. 18.4%), bleeding of any grade (50.5% vs. 60.2%), major hemorrhage (5.9% vs. 10.2%), diarrhea (21.8% vs. 32.7%), hypertension (12.9% vs. 20.4%); and neutropenia (31.7% vs. 15.3%);

◦	Despite higher rates of grade ≥ 3 neutropenia in the zanubrutinib arm (22.8% vs. 8.2% for ibrutinib), rates of infection remained similar in patients taking zanubrutinib and ibrutinib (all grade: 69.3% vs. 71.4%; grade ≥ 3: 18.8% vs. 23.5%); and

◦	No additional patients discontinued treatment due to AEs in the zanubrutinib arm, compared to an additional five patients in the ibrutinib arm (4% vs 14.3%). No additional patients had an adverse event leading to death in both arms (1.0% vs. 4.1%).

•	In the 26 centrally confirmed MYD88WT patients, the overall response rate (ORR) assessed by IRC was 80.8%, with a major response rate of 50.0%, including a VGPR rate of 26.9%;

•	Progression-free survival (PFS) event-free rate at 12 months was 72.4%;

•	In this cohort of 28 patients with MYD88WT or mutation unknown genotype, the most frequently reported AEs (≥ 20%) were diarrhea, anemia, contusion, pyrexia, and upper respiratory tract infection. Major hemorrhage was reported in 2 patients, and atrial fibrillation was reported in 1 patient. There were no fatal AEs; and

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•	Two patients (7.1%) discontinued zanubrutinib due to adverse events, and 6 patients (14.3%) discontinued due to disease progression.

•	As of January 29, 2020, with a median follow-up of 35.3 months, 73% remained on treatment;

•	The ORR was 96% and the VGPR/CR rate was 46%;

•	The proportion of patients achieving a best response of VGPR or CR increased with treatment duration;

•	Three-year PFS event-free rate was 80%, and overall survival was 83%;

•	Reasons for treatment discontinuation included AEs in 13% of patients, disease progression in 10%, and other in 4%;

•	The most commonly reported AEs (≥ 20%) were upper respiratory tract infection (55%), contusion (33%, all grade 1), cough (23%), and diarrhea (21%);

•	62.3% of patients (48/77) experienced at least one grade ≥3 AE and five patients experienced AEs leading to death;

•	AEs of interest included minor bleeding (35%), hypertension (18%), major hemorrhage (5%), and atrial fibrillation/flutter (5%).

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•	Fully-enrolled Phase 3 ASPEN clinical trial in patients with Waldenström’s macroglobulinemia (WM) comparing zanubrutinib to ibrutinib (NCT03053440), currently the only approved BTK inhibitor for WM;

•	Phase 3 SEQUOIA trial comparing zanubrutinib with bendamustine plus rituximab in patients with treatment-naive (TN) chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) (NCT03336333);

•	Phase 3 ALPINE trial comparing zanubrutinib to ibrutinib in patients with relapsed/refractory (R/R) CLL/SLL (NCT03734016);

•	Phase 2 trial in combination with GAZYVA® (obinutuzumab) in patients with R/R follicular lymphoma (FL) (NCT03332017);

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•	Phase 3 trial comparing zanubrutinib and rituximab to bendamustine and rituximab in patients with untreated MCL (NCT04002297);

•	Phase 2 MAGNOLIA trial in patients with R/R marginal zone lymphoma (MZL) (NCT03846427);

•	Phase 2 ROSEWOOD trial (NCT03332017) in China comparing obinutuzumab and zanubrutinib vs obinutuzumab alone in treating patients with R/R FL;

•	Phase 2 trial (NCT04382586) in the U.S. comparing zanubrutinib plus supportive care to placebo plus supportive care for the treatment of patients with COVID-19 disease and pulmonary distress;

•	Phase 2 trial (NCT03332173) in China in patients with R/R WM; and

•	Completed Phase 2 trials in China in patients with R/R MCL (NCT03206970) and R/R CLL/SLL (NCT03206918).

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•	Phase 3 results comparing tislelizumab plus chemotherapy to chemotherapy alone met its primary endpoint

•	Company to host investor conference call and webcast on ASCO clinical updates on Friday, May 29 at 8:00 p.m. ET

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The trial achieved the primary endpoint of progression-free survival (PFS) as assessed by Independent Review Committee (IRC); PFS was significantly improved with tislelizumab plus chemotherapy (Arms A and B) compared with chemotherapy alone (Arm C), regardless of tumor cell PD-L1 expression. Across all arms, median overall survival was not reached, and median number of treatment cycles were comparable;

•	Median PFS was 7.6 months for both tislelizumab arms compared to 5.5 months for chemotherapy alone. The hazard ratio (HR) for the comparison of Arm A vs. Arm C was 0.52 (95% confidence interval (CI), 0.4-0.7; p=0.0001), the HR for the comparison of Arm B vs. Arm C was 0.48 (95% CI, 0.3-0.7; p <0.0001);

•	Additionally, the objective response rates (ORR) were meaningfully higher for patients receiving tislelizumab; ORRs were 73% (95% CI 64%-80%) and 75% (66%-82%) in Arm A and Arm B, respectively versus 50% (40% - 59%) in Arm C;

•	Treatment with tislelizumab plus chemotherapy also roughly doubled the median duration of response (DoR) compared to chemotherapy alone. In the tislelizumab cohorts, DoR was 8.2 months for Arm A and 8.6 months for Arm B, while DoR in the Arm C was 4.2 months;

•	Treatment with tislelizumab and chemotherapy was generally well-tolerated in patients with NSCLC and in line with the known safety profiles of tislelizumab, chemotherapy, and underlying NSCLC. No new safety signals were identified with the addition of tislelizumab to chemotherapy;

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Most treatment-related AEs (TRAEs) were mild or moderate in severity; the most common TRAEs (≥ 20%) of any grade in all patients were (Arm A, Arm B, Arm C, respectively) hematologic in nature and included anemia (82.5%; 88.1%; 74.4%), alopecia (64.2%; 68.6%; 61.5%), decreased neutrophil count (62.5%; 61.0%; 58.1%), decreased white blood cell count (52.5%; 57.6%; 53.0%), leukopenia (47.5%; 55.9%; 47.9%), neutropenia (42.5%; 42.4%; 47.0%), and decreased appetite (41.7%; 41.5%; 29.9%);

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Serious treatment-related AEs (TRAEs) were reported in 27 patients in Arm A, 28 patients in Arm B and 17 patients in Arm C; serious TRAEs reported in Arm A and Arm B, respectively, included decreased neutrophil count (n=4; n=4), febrile neutropenia (n=2; n=3), pneumonitis (n=3; n=2), leukopenia (n=2; n=1), increased blood creatine phosphokinase (n=2 [Arm B]), decreased platelet count (n=1; n=2), bone marrow failure (n=2; n=1), rash (n=2 [Arm A]), and pyrexia (n=2 [Arm A]). The most commonly reported

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•	Tislelizumab-related grade ≥3 AEs occurred in 36.7% and 40.7% of patients in Arm A and Arm B, respectively;

•	Treatment-emergent AEs (TEAEs) leading to death were reported in 4 patients (3.3%) in Arm A, 5 patients (4.2%) in Arm B, and 5 patients (4.3%) in Arm C; and

•	Potential immune-mediated AEs occurred in 51.7% (A), 47.5% (B), and 18.8% (C) of patients. Most were low grade, did not require corticosteroid treatments, and did not lead to discontinuation of any treatment component. The most commonly reported immune-mediated AE was pneumonitis; grade ≥3 pneumonitis occurred in 2.5%, 3.4%, and 0.9% of patients in Arms A, B, and C, respectively.

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