Efficacy, retention, and safety of tofacitinib in real-life: Hur-bio monocentric experience

Background/aim: To assess the real-life efficacy, retention rate, and safety data of tofacitinib in rheumatoid arthritis (RA) patients. Materials and methods: We analyzed all patients registered in the HURBİO database who received at least 1 dose of tofacitinib. Patients who received at least one dose were included in retention analysis; patients with at least 1 control visit were included in efficacy and safety analysis. Factors predicting good response at the last follow-up visit were analyzed by logistic regression analysis. Drug retention rates were calculated using the Kaplan–Meier method and predictors of drug retention were determined by Cox proportional hazard model. Adverse events, reasons for switching, and discontinuation were also determined. Results: Two hundred and forty-seven (210, 85.0% female) patients were included in the study. The median duration of tofacitinib treatment was 10.2 (20.2) [med, (IQR)] months. Two hundred and four (82.6%) patients were included in safety and efficacy analysis; 45.6% of patients were in low-disease activity (LDA) state (DAS28-CRP ≤ 3.2). Predictors of LDA were being biologic-naïve [aOR 2.53 (1.31–4.88); 95% CI] and RF negativity [aOR 2.14 (1.12–4.07); 95% CI]. At 1 year, the overall tofacitinib retention rate was 63.9% with no relevant predicting factor. Response and retention rates of tofacitinib were similar in patients with and without concomitant csDMARDs. Treatment failure was the most common cause of discontinuation. The most common infectious and laboratory adverse events were herpes zoster infection (3.9 per 100 patient-years) and elevation in ALT (x3UNL: 9.7 per 100 patient-years), respectively. Conclusion: Tofacitinib is effective as monotherapy or in combination with csDMARDs. It is a well-tolerated treatment option in Turkish RA patients.PubMe

Bypass of a protein barrier by a replicative DNA helicase

Replicative DNA helicases generally unwind DNA as a single hexamer that encircles and translocates along one strand of the duplex while excluding the complementary strand (known as steric exclusion). By contrast, large T antigen, the replicative DNA helicase of the simian virus 40 (SV40), is reported to function as a pair of stacked hexamers that pumps double-stranded DNA through its central channel while laterally extruding single-stranded DNA. Here we use single-molecule and ensemble assays to show that large T antigen assembled on the SV40 origin unwinds DNA efficiently as a single hexamer that translocates on single-stranded DNA in the 3'-to-5' direction. Unexpectedly, large T antigen unwinds DNA past a DNA–protein crosslink on the translocation strand, suggesting that the large T antigen ring can open to bypass bulky adducts. Together, our data underscore the profound conservation among replicative helicase mechanisms, and reveal a new level of plasticity in the interactions of replicative helicases with DNA damage.