A pilot study of orelabrutinib treatment in three cases of refractory/relapsed autoimmune haemolytic anaemia/Evans syndrome.

Currently, there is no effective treatment for refractory/relapsed (R/R) autoimmune haemolytic anaemia (AIHA), associated with poor quality of life. Bruton tyrosine kinase inhibitors have begun to be used in some autoimmune diseases. We initiated the clinical trial of orelabrutinib treatment on R/R AIHA/Evans Syndrome, which is in progress. The preliminary results showed that nine of the 12 enrolled patients responded to orelabrutinib treatment. Here, we reported three cases who have completed the treatment and were followed up for 6 months, achieving complete or partial remission. Orelabrutinib is expected to become a new second-line treatment for R/R AIHA/Evans syndrome.

Efficacy and safety of orelabrutinib in relapsed/refractory idiopathic multicentric Castleman disease: A single-centre, retrospective study.

Idiopathic multicentric Castleman disease (iMCD) is a rare and heterogeneous lymphoproliferative disorder that lacks standardised treatment options for patients with refractory or relapsed (r/r) disease. Blocking Bruton's tyrosine kinase (BTK) has emerged as a promising therapeutic approach for iMCD without depleting B cells. This single-centre, retrospective study enrolled 10 patients with r/r iMCD who were treated with orelabrutinib, a novel, next-generation BTK inhibitor. The median age at orelabrutinib initiation was 48 (range: 31-58) years. The overall response rate was 70% (7/10 patients, 95% CI: 34.8-93.3), with 20% (n = 2) achieving complete response and 50% (n = 5) achieving partial response. The median time to response was 9.8 (range: 5.9-20.5) months. Patients in the non-responder group also demonstrated a continuous improvement in haemoglobin (91-105 g/L) and albumin (32-38 g/L) levels at month 12 of treatment despite not fulfilling response criteria. No grade 3 or higher adverse events occurred during the median time to the next treatment of 29.0 (range: 15.0-36.2) months. No patient mortality was recorded during the median follow-up duration of 32.8 (range: 15.0-36.9) months. In conclusion, orelabrutinib is a safe and effective regimen for r/r iMCD.

Indirect comparisons of efficacy of zanubrutinib versus orelabrutinib in patients with relapsed or refractory chronic lymphocytic leukemia/small lymphocytic lymphoma or relapsed or refractory mantle cell lymphoma.

We conducted two indirect comparisons to estimate the efficacy of zanubrutinib versus orelabrutinib in Chinese patients with relapsed or refractory (R/R) chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) or R/R mantle cell lymphoma (MCL). An unanchored matching-adjusted indirect comparison (MAIC) was performed in R/R CLL/SLL patients. Individual patient data from zanubrutinib trial (BGB-3111-205) were adjusted to match the aggregated data from the orelabrutinib trial (ICP-CL-00103). A naïve comparison was performed in R/R MCL for the different response assessment methodology and efficacy analysis set between the zanubrutinib (BGB-3111-206) and orelabrutinib (ICP-CL-00102) trials. Efficacy outcomes included ORR and PFS. In R/R CLL/SLL patients, after matching, IRC-assessed ORR was comparable (86.6% vs. 92.5%; risk difference, -5.9% [95% CI: -15.8%-3.8%]); IRC-assessed PFS was similar with a favorable trend in zanubrutinib over orelabrutinib (HR, 0.74 [95% CI: 0.37-1.47]) and the 18-month PFS rate was numerically higher in zanubrutinib (82.9% vs. 78.7%). In R/R MCL patients, naïve comparison showed investigator-assessed ORR was similar (83.7% vs. 87.9%; risk difference, -4.2% [95% CI: -14.8%-6.0%]), and CR rate was significantly higher in zanubrutinib over orelabrutinib (77.9% vs. 42.9%; risk difference, 35.0% [95% CI: 14.5%, 53.7%]). Investigator-assessed PFS was similar with a favorable trend (HR, 0.77 [95% CI: 0.45-1.32]) in zanubrutinib over orelabrutinib and the 12-month PFS rate was numerically higher in zanubrutinib (77.5% vs. 70.8%). MAIC result showed zanubrutinib demonstrated favorable PFS over orelabrutinib for R/R CLL/SLL patients. The naïve comparison showed zanubrutinib had favorable PFS and higher CR rate than orelabrutinib for R/R MCL patients.

Orelabrutinib-bruton tyrosine kinase inhibitor-based regimens in the treatment of central nervous system lymphoma: a retrospective study.

BACKGROUND: Central nervous system lymphoma (CNSL) is an aggressive lymphoma. Orelabrutinib, an oral Bruton tyrosine kinase inhibitor, is a new treatment strategy for CNSL. This study aims to evaluate the efficacy and safety of orelabrutinib-based regimens in the treatment of patients with CNSL. METHODS: Twenty-three patients with CNSL were included in this retrospective study. All patients received the orelabrutinib-based regimen. Efficacy was evaluated based on investigators' assessment of overall response rate (ORR), complete response/unconfirmed complete response (CR/CRu), partial response (PR), stable disease (SD), progressive disease (PD), duration of response (DOR), progression-free survival (PFS) and overall survival (OS). The safety of orelabrutinib-based regimens has also been evaluated. RESULTS: A total of 17.39% of patients received orelabrutinib-based regimens for consolidation therapy, and 82.61% of patients for induction therapy (4 newly diagnosed CNSL, 15 relapsed/refractory CNSL). In the newly diagnosed CNSL group, the ORR was 100% (1 CR, 1 CRu, 2 PR). The 6-month DOR rate, 6-month PFS rate, and 6-month OS rate were 100%, 100%, and 100%, respectively. Of the 15 relapsed/refractory CNSL patients, five therapy regimens were applied (orelabrutinib, n = 3; orelabrutinib/immunotherapy, n = 3; orelabrutinib/chemotherapy, n = 2; orelabrutinib/immunochemotherapy, n = 6; orelabrutinib/radiotherapy, n = 1). The ORR was 60.00% (4 CR, 5 PR). The 6-month DOR rate, 6-month PFS rate, and 6-month OS rate were 92.30%, 67.70%, and 70.00%, respectively. Twenty-one patients reported adverse events (AEs), and 6 patients experienced grade ≥ 3 AEs. CONCLUSION: Orelabrutinib-based regimens were efficacious and well-tolerated in patients with CNSL. These combined therapies offer a new potential therapeutic strategy for patients with CNSL.

[Efficacy and safety analysis of the OR-CHOP regimen for the treatment of MCD subtype diffuse large B cell lymphoma in the real-world setting].

Objective: To investigate the efficacy and safety of orelabrutinib combined with R-CHOP in the treatment of MCD subtype diffuse large B cell lymphoma (DLBCL) . Methods: Twenty-three MCD subtype patients whose gene-subtype classification was based on baseline tumor tissue and/or baseline plasma using the LymphGen algorithm from June 2022 to June 2023 in the First Affiliated Hospital of Nanjing Medical University were retrospectively enrolled in the analysis. All patients were treated with R-CHOP or R-miniCHOP in Course 1, OR-CHOP or OR-miniCHOP (21 days for one course) in Courses 2-6, and R-monotherapy in Courses 7-8. Results: Of the 23 patients, the median age was 58 years (range: 30-81 years), and 11 (47.8% ) aged >60 years. Fifteen cases (65.2% ) had international prognostic index (IPI) scores of 3 to 5. The top 10 mutated genes in the gDNA tissues were PIM1 (78.3% ), MYD88 (69.6% ), ETV6 (43.5% ), BTG1 (39.1% ), CD79B (43.5% ), HIST1H1E (39.1% ), BTG2 (34.8% ), KMT2D (30.4% ), CD58 (26.1% ), and CDKN2B (21.7% ). The consistency rate of the tissue and plasma mutations was 80%, while the baseline plasma ctDNA burden was closely correlated with the LDH levels and IPI scores (P<0.05). All patients received 5 courses of OR-CHOP regimens. The mid-term (after 3 courses) evaluation showed that the overall response rate (ORR) was 100% (23/23), with 22 patients (95.65% ) achieving complete remission (CR), and 1 patient (4.35% ) achieving partial remission (PR). The ORR after the end of treatment (EOT) was 95.65% (22/23). Moreover, 21 patients (91.30% ) obtained CR, 1 patient (4.35% ) obtained PR, and 1 patient (4.35% ) obtained progression disease (PD). Of the 21 patients who had the dynamic EOT-ctDNA burden, only four patients (19.0% ) did not achieve EOT-ctDNA clearance, while the other 17 patients (81.0% ) achieved EOT-ctDNA clearance. The median follow-up time was 20.8 (15.3-30.0) months, while the median progression-free survival (PFS) and overall survival (OS) were not reached. The 2-year PFS rate was 71.8% (95% CI 54.7% -94.2% ), while the 2-year OS rate was 91.3% (95% CI 80.5% -100.0% ). Furthermore, the OR-CHOP regimen was generally well tolerated during clinical use, with hematological toxicity being the main adverse effect. Conclusion: This study revealed that the OR-CHOP regimen can be used as an effective and safe first-line treatment for MCD subtype DLBCL.

Bruton's tyrosine kinase (BTK) inhibitors for the treatment of primary central nervous system lymphoma (PCNSL): current progress and latest advances.

The incidence of primary central nervous system lymphoma (PCNSL) has steadily increased, particularly in elderly patients. Although highly responsive to first-line chemotherapy and radiotherapy, approximately 50% of patients relapse or become refractory within 1 year. Prognosis following relapse is dismal and no standard salvage therapy exists. Bruton's tyrosine kinase (BTK), a key regulator of the B-cell receptor (BCR) pathway, has emerged as a promising therapeutic target. The first BTK inhibitor ibrutinib has been evaluated in the relapsed/refractory PCNSL setting, with overall response rates of 51.9%-89.0% and median progression-free survival of 4.6-4.8 months. However, ibrutinib inhibits several kinases in addition to BTK, leading to off-target effects. Second-generation BTK inhibitors have since been developed, which afford greater selectivity for BTK and fewer off-target effects. We review current practices in the diagnosis and evaluation of PCNSL, as well as clinical trials of BTK inhibitors in PCNSL and future developments in PCNSL treatment.

Case report: BTK inhibitors is effective in type II mixed cryoglobulinemia with wild-type MyD88.

This study presents two cases of type II mixed cryoglobulinemia. One case is essential, while the other is presumably associated with hepatitis B virus (HBV) infection. Both patients tested positive for monoclonal IgMκ, but negative for MyD88 mutation. They showed resistance to rituximab combined with a glucosteroid regimen, but responded positively to BTK inhibitors. These cases highlight the remarkable effectiveness of BTK inhibitors in treating refractory type II cryoglobulinemia without MyD88 mutation. The first patient achieved rapid complete remission of nephrotic syndrome within one month of starting ibrutinib, along with a significant reduction in cryoglobulin levels and abnormal clonal cells. The second patient had a rapid disappearance of rash within three days and accelerated wound healing within one week of initiating orelabrutinib, accompanied by a reduction in C-reactive protein. However, there was no reduction in cryoglobulin levels during the 12-month follow-up. These findings suggest varied mechanisms of action of BTK inhibitors in type II cryoglobulinemia through different mechanisms.

Chidamide and orelabrutinib synergistically induce cell cycle arrest and apoptosis in diffuse large B-cell lymphoma by regulating the PI3K/AKT/mTOR pathway.

OBJECTIVE: The initial therapeutic approach for diffuse large B-cell lymphoma (DLBCL) entails a rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) regimen. However, 40% of patients exhibit suboptimal responses, with some experiencing relapse and refractory conditions. This study aimed to explore novel therapeutic strategies and elucidate their underlying mechanisms in DLBCL. METHODS: Bioinformatics techniques were employed to scrutinize correlations between the HDAC1, HDAC2, HDAC3, HDAC10, BTK, MYC, TP53, and BCL2 genes in DLBCL. In vitro experiments were conducted using DB and SU-DHL-4 cells treated with chidamide, orelabrutinib, and a combination of both. Cell viability was assessed by cell counting kit-8. Cell apoptosis and the cell cycle were determined using flow cytometry. Reactive oxygen species (ROS) production and mitochondrial function were assessed through ROS and JC-1 staining. RNA sequencing and western blot analyses were conducted to elucidate the molecular mechanisms underlying the combined action of chidamide and orelabrutinib in DLBCL cells. RESULTS: This investigation revealed markedly enhanced antiproliferative effects when chidamide was combined with orelabrutinib. Compusyn software analysis indicated a synergistic effect of chidamide and orelabrutinib in inhibiting DLBCL cell proliferation, with a combination index (CI) < 1. This synergy further manifested as augmented cell cycle arrest, apoptosis induction, the downregulation of cell cycle-associated and antiapoptotic proteins, and the upregulation of proapoptotic proteins. Furthermore, the western blot and RNA-Seq findings suggested that combining chidamide and orelabrutinib modulated the PI3K/AKT/mTOR signaling pathway, thereby promoting DLBCL cell cycle arrest and apoptosis. CONCLUSION: The findings of this study provide a compelling justification for the clinical utilization of chidamide and orelabrutinib to treat relapsed/refractory DLBCL.

Efficacy and safety of Orelabrutinib-based regimens in diffuse large B-cell lymphoma: a single-center retrospective analysis.

Currently, combining chemotherapy with Bruton tyrosine kinase inhibitors (BTKi) has demonstrated significant effectiveness in treating patients with diffuse large B-cell lymphoma. Orelabrutinib is a second-generation BTK inhibitor, and presently, there have been few reports of Orelabrutinib being used to treat DLBCL. We conducted a retrospective investigation to explore the safety and efficacy of Orelabrutinib in combination with chemotherapy or immunotherapy. The study comprised 19 patients with a median age of 61 years. The overall response rate (ORR) was 89.5% with a complete response (CR) rate of 73.7% and a partial response rate (PR) of 15.8%. The estimated 2-year overall survival (OS) and progression-free survival (PFS) rates were 78.6% (95%CI, 59.8%-100%) and 72.2% (95% CI, 52.4%-99.6%), respectively, with a median follow-up time of 11 months (range 2-24). The most prevalent grade 3 or 4 adverse events (AEs), neutropenia (52.6%), anemia (36.8%), thrombocytopenia (26.3%), febrile neutropenia (26.3%), and lung infection (10.5%), were the most common. Our results reveal that Orelabrutinib is an effective therapy for DLBCL patients. Furthermore, our first investigation of the Orelabrutinib application lays a foundation for larger retrospective studies.

Quantification of orelabrutinib in human plasma and cerebrospinal fluid by liquid chromatography tandem mass spectrometry.

A sensitive and simple method was developed to determine orelabrutinib in human plasma and cerebrospinal fluid by liquid chromatography tandem mass spectrometry (LC-MS/MS). The samples were prepared by simple protein precipitation with by 0.1% formic acid acetonitrile solution and efficient separations were performed on the Thermo Hypersll GOLD C18 column (2.1 mm × 150 mm, 5 µm) under a gradient program in a total run time of 9 min. The orelabrutinib was detected by electrospray ionization in positive ion mode with selective reaction monitoring (SRM) and mass spectrometric conditions were optimized in order to increase selectivity and sensitivity. The developed method was validated in terms of its accuracy, precision, selectivity, linearity, recovery, matrix effect, stability, and limits of quantification (LOQ). The lower limit of quantification is 0.50 ng/mL, the intraday and interday precision RSD are both less than 15%, and the recovery rate is 85.7%-92.9%. Finally, the method was successfully applied for the quantitation of orelabrutinib in human plasma and cerebrospinal fluid of clinical patients treated with orelabrutinib.

[Evaluation of the Short-Term Efficacy and Safety of Orelabrutinib Combined with High-Dose Methotrexate in the First-line Treatment of Elderly Patients with High Risk Primary Central Nervous System Lymphoma].

OBJECTIVE: To explore the short-term efficacy and adverse reactions of orelabrutinib combined with high-dose methotrexate (HD-MTX) in the first-line treatment of elderly high-risk primary central nervous system lymphoma (PCNSL), as well as the survival of patients. METHODS: Twenty-five elderly patients with high-risk primary central nervous system diffuse large B-cell lymphoma admitted to Fujian Provincial Hospital from June 2016 to June 2022 were enrolled in this study, and complete clinical data from all patients were collected retrospectively, and the cut-off for follow-up was December 2022. 15 patients had received temmozolomide combined with HD-MTX regimen for at least four cycles, sequential lenalidomide maintenance therapy, while 10 patients had received orelabrutinib combined with HD-MTX regimen for at least four cycles, sequential orelabrutinib maintenance therapy. The short-term efficacy and adverse reactions of the two groups of patients after treatment were observed. Kaplan-Meier was used to analyze the progression-free survival (PFS) and time to progression (TTP). RESULTS: The objective response rate (ORR) and 2-year median FPS of orelabrutinib combined with HD-MTX regimen group were similar to the temozolomide combined with HD-MTX regimen group (ORR: 100% vs 66.7%; 2-year median PFS: 16 months vs 15 months, P>0.05). The 2-year median TTP of the orelabrutinib+HD-MTX regimen group was better than that of the temozolomide+HD-MTX regimen group (not reached vs 12 months, P<0.05). There were no significant differences in adverse reactions such as gastrointestinal reactions, bone marrow suppression, liver and kidney damage, cardiotoxicity, pneumonia and bleeding between these two groups (P>0.05). CONCLUSION: For elderly patients with high-risk PCNSL, orelabrutinib combined with HD-MTX has reliable short-term efficacy, good safety, and tolerable adverse reactions, which is worthy of clinical promotion.

Orelabrutinib and venetoclax synergistically induce cell death in double-hit lymphoma by interfering with the crosstalk between the PI3K/AKT and p38/MAPK signaling.

PURPOSE: Double-hit lymphoma (DHL) is a rare and aggressive mature B-cell malignancy with concurrent MYC and BCL2 rearrangements. When DHL becomes relapsed or refractory, it becomes resistant to the majority of therapeutic approaches and has subpar clinical results. Therefore, innovative therapeutics for this particular patient population are urgently needed. METHODS: Orelabrutinib, a new oral BTK inhibitor, combined with the Bcl-2 inhibitor venetoclax, was used to confirm the antitumor effect of DHL. Cell counting kit-8 and Annexin V-FITC/PI assays were used to examine the interaction of this combined regimen on DHL cell lines and primary lymphoma cells. RNA sequencing, EdU incorporation assay, mitochondrial membrane potential assay, and western blotting were employed to explore the molecule mechanism for the cytotoxicity of orelabrutinib with or without venetoclax against DHL cell lines. RESULTS: In this study, orelabrutinib combined with venetoclax synergistically induced DHL cell death, as evidenced by the inhibition of cell proliferation, the induct of cell cycle arrest, and the promotion of cell apoptosis via the mitochondrial pathway. Orelabrutinib treatment alters genome-wide gene expression in DHL cells. The combined regimen decreases the expression of BTK and Mcl-1, potentially interfering with the activity and crosstalk of PI3K/AKT signaling and p38/MAPK signaling. In addition, the combination of orelabrutinib and venetoclax shows cytotoxic activity in primary B-lymphoma cells. CONCLUSION: In summary, these findings reveal a novel therapy targeting BCR signaling and the Bcl-2 family for DHL patients with a poor prognosis.

High-dose methotrexate, thiotepa, orelabrutinib combined with or without rituximab in primary or secondary central nervous system diffuse large B-cell lymphoma: a single-center retrospective analysis.

Purpose: Central nervous system lymphoma (CNSL) is an aggressive non-Hodgkin's lymphoma (NHL) confined to the central nervous system (CNS). Orelabrutinib is an oral second-generation Bruton tyrosine kinase (BTK) inhibitor and a novel therapeutic strategy for CNSL. The purpose of this study was to evaluate the effectiveness and safety of high-dose methotrexate (HD-MTX), thiotepa, and orelabrutinib combined with or without rituximab (MTO±R)regimen in the treatment of patients with CNSL. Methods: A total of 14 patients with CNS diffuse large B-cell lymphoma (DLBCL) were included in this retrospective study. All patients received the regimen MTO±R. Overall response rate (ORR), complete response rate(CR), partial response (PR), stable disease (SD), progressive disease (PD), progression-free survival (PFS), overall survival (OS), and the safety of MTO±R were assessed by the investigator. Results: Fourteen patients were evaluable for safety, and 13 patients were evaluable for efficacy. The overall CR rate was 69.2%, and the ORR was 92.3% for total patients. For PCNSL, the CR rate and ORR were 55.6% and 88.9%, respectively. For relapsed/refractory CNSL, the CR rate and ORR were 66.7% and 91.7%, respectively. The median follow-up time was 12.8 months. The median PFS was 11.3 months, and the median OS was not achieved. The 12-month PFS and OS rates were 60% and 70%, respectively. Adverse events occurred in 17 cycles, and Grade 3 AEs occurred in 5 patients (35.7%). Conclusion: MTO±R was an efficacious and well-tolerated regimen in patients with CNSL. A novel BTK inhibitor in combination with chemotherapy offers a new potential therapeutic strategy for patients with CNSL.

The preclinical discovery and development of orelabrutinib as a novel treatment option for B-cell lymphoid malignancies.

INTRODUCTION: Bruton's tyrosine kinase (BTK) inhibitors have recently been approved for clinical use against several B-cell indolent lymphoid malignancies, both as single agents or in combination. One second-generation BTK inhibitor that is being developed for the treatment of B-cell hematological malignancies, as well as for autoimmune disorders, is orelabrutinib. AREAS COVERED: This paper reviews recent developments in the use of orelabrutinib against B-cell indolent lymphoid malignancies such as chronic lymphocytic leukemia, mantle cell lymphoma, diffuse large B-cell lymphoma, Waldenstrom macroglobulinemia and central nervous system lymphoma. Google Scholar and PubMed were initially searched for articles, and the corpus of articles was broadened by reviewing the references of the identified papers. All were in English. The corpus comprised papers from 2016 to April 2023. In addition, a manual search was performed of conference proceedings from the last five years of The American Society of Hematology, American Society of Clinical Oncology and the European Hematology Association. EXPERT OPINION: Orelabrutinib is an active drug in indolent and aggressive B-cell lymphoid malignancies. It demonstrates high selectivity, good efficacy and an excellent safety profile. Nevertheless, further clinical trials are required to optimize its use. In addition, several other highly selective BTK inhibitors are being examined in early-phase studies.

Evaluation of orelabrutinib monotherapy in patients with relapsed or refractory Waldenström's macroglobulinemia in a single-arm, multicenter, open-label, phase 2 study.

Background: Orelabrutinib is a novel, small molecule, selective irreversible Bruton tyrosine kinase inhibitor. The purpose of this study was to evaluate the efficacy and safety of orelabrutinib in patients with relapsed or refractory Waldenström's macroglobulinemia (R/R WM). Methods: This is a prospective, multicenter study of orelabrutinib in patients with WM who had at least one prior line of treatment. Orelabrutinib was administered orally at a daily dose of 150 mg until disease progression or unacceptable toxicity. The primary endpoint was major response rate (MRR) assessed by the Independent Review Committee (IRC) according to IWWM-6. This study is registered with ClinicalTrials.gov, NCT04440059. This trial was also registered on Center for Drug Evaluation (www.chinadrugtrials.org.cn) in March 2019, with a number of CTR2019036. Findings: Between August 2019 and December 2020, 66 R/R WM patients were assessed for eligibility. Forty-seven eligible patients were evaluated for efficacy at a median follow-up of 16.4 months (interquartile range: 12.5, 19.5). As assessed by IRC, the MRR was 80.9%, and the overall response rate was 89.4%. The median time to at least a minor response was 1.9 months. The PFS rates was 89.4% at 12 months. For patients with MYD88L265P /CXCR4NEG, MYD88L265P /CXCR4 S338X, and MYD88NEG /CXCR4NEG mutations, the MRRs were 84.6%, 100%, and 25.0%. Most adverse events were Grades 1 or 2 (91.0%). The common grade 3 or higher adverse events occurring were neutropenia (10.6%), thrombocytopenia (6.4%), and pneumonia (4.3%). Serious adverse events (SAE) occurred in 10 patients (21.3%). One treatment-related death was reported (hepatitis B reactivation). Interpretation: Orelabrutinib has shown good efficacy and manageable safety profiles in patients with R/R WM. Funding: InnoCare Pharma.

Development of a UPLC-MS/MS method for the determination of orelabrutinib in rat plasma and its application in pharmacokinetics.

The aim of the present study was to establish an ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the determination of orelabrutinib in rat plasma using futibatinib as internal standard (IS), and to apply it for a pharmacokinetic study in rats. Orelabrutinib was extracted from plasma by protein precipitation and quantitatively analyzed by UPLC-MS/MS. An Acquity UPLC BEH C18 column was used for rapid separation by gradient elution using 0.1% formic acid and acetonitrile as mobile phases. The validation results of bioanalytical methodology showed that the linearity of orelabrutinib in plasma samples was good within the concentration range of 1-2000 ng/ml. The lower limit of quantification (LLOQ) was 1 ng/ml. The precision of orelabrutinib ranged from 1.4% to 11.5%, with intra-day and inter-day accuracy ranging from -5.7% to 7.7% and -0.2% to 12.5%, respectively. The selectivity, stability, matrix effect and recovery of the method all met the requirements of quantitative analysis of biological samples. The method was simple, sensitive, accurate and specific, and had high recovery rate. It also could be successfully applied to the pharmacokinetic study of rats.

Evaluating orelabrutinib as a novel treatment option for relapsed/refractory chronic lymphocytic leukemia in China.

INTRODUCTION: The covalent Bruton's tyrosine kinase (BTK) inhibitor ibrutinib has been approved in the USA for B cell malignancies for almost ten years and has improved the survival of patients with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). Orelabrutinib is a novel, highly selective covalent BTK inhibitor with proven efficacy and acceptable safety profile. In 2020, it was approved for the treatment of relapsed/refractory (R/R) CLL/SLL in China. AREAS COVERED: In this review, we summarized the current clinical trials exploring orelabrutinib monotherapy or orelabrutinib-based combination regimens in CLL/SLL, especially R/R CLL/SLL. Pharmacodynamics, pharmacokinetics, clinical efficacy and safety of orelabrutinib are also discussed. EXPERT OPINION: Orelabrutinib selectively inhibits BTK via covalent binding and exhibits linear pharmacokinetics. BTK is the only kinase targeted by orelabrutinib, and a few off-target toxicities of orelabrutinib have been reported. The phase I/II trial demonstrated the efficacy and safety of orelabrutinib in patients with R/R CLL/SLL; however, further clinical trials are needed to compare orelabrutinib with ibrutinib in patients with R/R CLL/SLL and to evaluate its efficacy and safety in patients with treatment-naive CLL/SLL.

Orelabrutinib Combined With Lenalidomide and Immunochemotherapy for Relapsed/Refractory Primary Central Nervous System Lymphoma: A Retrospective Analysis of Case Series.

Background: Relapsed/refractory (r/r) primary central nervous system lymphoma (PCNSL) is an intractable situation without sound treatment. Bruton's tyrosine kinase (BTK) represents an attractive drug target in PCNSL. Orelabrutinib is a new-generation BTK inhibitor with high cerebrospinal fluid (CSF) concentration. This study aimed to evaluate the efficacy and safety of orelabrutinib-containing combination therapy in patients with r/r PCNSL. Methods: We retrospectively analyzed r/r PCNSL patients who received combination therapy with rituximab, high-dose methotrexate, temozolomide, orelabrutinib and lenalidomide, and further explored the relationship between the efficacy and genetic characteristics. Results: A total of fifteen patients were included in this retrospective study. The overall response rate (ORR) was 86.7%, the complete remission (CR) rate was 73.3% and the disease control rate (DCR) was 93.3%. Among 13 responders, 9 patients are still receiving oral orelabrutinib and lenalidomide. The most common adverse event (AEs) was transaminase increase (66.7%). No grade 4 AE or drug-related death was reported. Genomic sequencing showed that patients who responded to orelabrutinib had abnormal NF-κB activation, while those who had no response were mainly enriched with transcriptional misregulation. Patients who had mutations in TLR, BCR, or NF-κB pathway achieved complete or partial response to the orelabrutinib-containing therapy. Moreover, the blood and cerebrospinal fluid circulating tumor DNA (ctDNA) were closely associated with tumor recurrence and treatment response and sustained tumor responses correlated with the clearance of ctDNA. Conclusion: Orelabrutinib-containing regimen was effective and well-tolerated in patients with r/r PCNSL. Genome sequencing of tumor samples could help to screen patients who may respond to the orelabrutinib-containing regimen, and liquid biopsy may contribute to tracing tumor burden and monitoring treatment response.

The Role of Bruton's Kinase Inhibitors in Chronic Lymphocytic Leukemia: Current Status and Future Directions.

The use of Bruton's tyrosine kinase (BTK) inhibitors has changed the management and clinical history of patients with chronic lymphocytic leukemia (CLL). BTK is a critical molecule that interconnects B-cell antigen receptor (BCR) signaling. BTKis are classified into two categories: irreversible (covalent) inhibitors and reversible (non-covalent) inhibitors. Ibrutinib was the first irreversible BTK inhibitor approved by the U.S. Food and Drug Administration in 2013 as a breakthrough therapy in CLL patients. Subsequently, several studies have evaluated the efficacy and safety of new agents with reduced toxicity when compared with ibrutinib. Two other irreversible, second-generation BTK inhibitors, acalabrutinib and zanubrutinib, were developed to reduce ibrutinib-mediated adverse effects. Additionally, new reversible BTK inhibitors are currently under development in early-phase studies to improve their activity and to diminish adverse effects. This review summarizes the pharmacology, clinical efficacy, safety, dosing, and drug-drug interactions associated with the treatment of CLL with BTK inhibitors and examines their further implications.

Current Role and Emerging Evidence for Bruton Tyrosine Kinase Inhibitors in the Treatment of Mantle Cell Lymphoma.

The Bruton tyrosine kinase inhibitors (BTKi), acalabrutinib, ibrutinib, and zanubrutinib, are all approved in the United States for the treatment of relapsed mantle cell lymphoma (MCL). BTKi as a class have become the preferred therapy for most of the patients with relapsed MCL, and ongoing clinical trials are evaluating whether combining BTKi with other targeted agents may deepen response and further improve outcomes. Emerging evidence supports the efficacy of BTKi-containing combinations as frontline treatment, and clinical studies to define the role of this class of drugs for newly diagnosed patients with MCL are in progress.