BTK blocking peptide

Rheumatoid arthritis is an autoimmune disorder causing joint deformity and work disability. Several drugs are available to deal with the disease including conventional drugs; biological drugs such as TNF alpha inhibitors, B cell-targeted drugs, T cell co-stimulation inhibitors, interleukin-6 inhibitors, and interleukin-1 inhibitors; and kinase inhibitory drugs. In spite of the broad spectrum of drugs available, the disease remains uncontrolled in a number of patients and there is a need for new drugs with better efficacy and universal response rate. The failure of the available drugs to control the disease can be owed to the complex pathogenesis with complementary pathways of disease progression. The blockade of one pathway cannot supersede pathogenesis through other complementary pathways. Janus kinase (JAK) and Bruton's tyrosine kinase (BTK) are the two important mediators of disease which control a number of signaling pathways involved in rheumatoid arthritis pathogenesis. In this study, using the computer-aided drug designing techniques (virtual screening, molecular docking, and molecular dynamics studies), we have designed piperidinyl dipyrrolopyridine-based dual inhibitors of Janus kinase and Bruton's tyrosine kinase. Dual JAK and BTK inhibitors seem promising to fight the complex pathogenesis of the disease at multiple fronts and can be the future drug for patients unresponsive to current remedies.

Tirabrutinib is a second-generation Bruton's tyrosine kinase inhibitor with greater selectivity than ibrutinib. Here, we conducted a multicenter, phase II study of tirabrutinib in patients with treatment-naive (Cohort A) or with relapsed/refractory (Cohort B) Waldenstrom's macroglobulinemia (WM). Patients were treated with tirabrutinib 480 mg once daily. The primary endpoint was major response rate (MRR; >= partial response). Secondary endpoints included overall response rate (ORR; >= minor response), time to major response (TTMR), progression-free survival (PFS), overall survival (OS), and safety. In total, 27 patients (18 in Cohort A; 9 in Cohort B) were enrolled. The median age was 71 y, and the median serum immunoglobulin M level was 3600 mg/dL. Among the patients, 96.2% had theMYD88(L265P)mutation. MRR and ORR were 88.9% and 96.3%, respectively (Cohort A: MRR, 88.9%; ORR, 94.4%; Cohort B: MRR, 88.9%; ORR, 100%). Median TTMR was 1.87 mo. PFS and OS were not reached with a median follow-up of 6.5 and 8.3 mo for Cohorts A and B, respectively. The most common adverse events (AEs) were rash (44.4%), neutropenia (25.9%), and leukopenia (22.2%), with most AEs classified as grade 1 or 2. Grade >= 3 AEs included neutropenia (11.1%), lymphopenia (11.1%), and leukopenia (7.4%). No grade 5 AEs were noted. All bleeding events were grade 1; none were associated with drug-related atrial fibrillation or hypertension. Although the follow-up duration was relatively short, the study met the primary endpoint. Therefore, tirabrutinib monotherapy is considered to be highly effective for both untreated and relapsed/refractory WM with a manageable safety profile. (JapicCTI-173646).