Randomized phase 2b trial of tofacitinib (CP-690,550) in de novo kidney transplant patients: efficacy, renal function and safety at 1 year

Planned randomized conversion from tacrolimus to sirolimus-based immunosuppressive regimen in de novo kidney transplant recipients

Planned conversion from tacrolimus to sirolimus was evaluated in de novo kidney transplant recipients. In this multicenter, randomized, open-label study, 297 patients were initially treated with tacrolimus, mycophenolate sodium and prednisone. Of the 283 patients reaching 3 months, 97 were converted to sirolimus (SRL), 107 were maintained on tacrolimus (TAC) and 79 were patients receiving TAC without criteria to undergo intervention at month 3 (TACex). The primary objective was to show superior estimated glomerular filtration rate (eGFR) in the SRL group at month 24. Of the 258 patients who completed 24 months, 91 (94%) were in the SRL group, 101 (94%) in the TAC group and 66 (84%) in the TACex group. In the intention-to-treat population there were no differences in eGFR (66.2 ± 25.3 vs. 70.7 ± 25.1, p = 0.817) or in the severity of chronic sclerosing lesions scores in 24-month protocol biopsies. Higher mean urinary protein-to-creatinine ratio (0.36 ± 0.69 vs. 0.15 ± 0.53, p = 0.03) and higher incidence of treated acute rejection between months 3-24 (13.4% vs. 4.7%, p = 0.047) were observed in SRL compared to TAC group. In this population planned conversion from TAC to SRL 3 months after kidney transplantation was not associated with improved renal function at 24 months.

JAK3 inhibition: what potential for the future?

JAK3 inhibition with the CP-690,550 compound has an immunosuppressive potency in murine models, nonhuman primates and humans. This drug blocks STAT5 activation in most T-cell subpopulations but less effectively in T-regulator cells. In low to moderate risk human kidney transplant recipients, combined with mycophenolate mofetil, steroids and an induction with basiliximab, CP-690,550 proved as effective as calcineurin inhibitors with regard to prevention of acute rejection but better than calcineurin inhibitors with regard to preservation of kidney function and histology. However, at the same time, an increased incidence of overimmunosuppression consequences (cytomegalovirus, BK virus and lymphoproliferation) was observed and led to discontinuation of this specific drug development in kidney transplantation.

Review article: dermatological complications of immunosuppressive and anti-TNF therapy in inflammatory bowel disease

BACKGROUND

With the expanding list of medications available to treat patients with inflammatory bowel disease (IBD), it is important to recognise adverse events, including those involving the skin. Dermatological adverse events may be confused with extra-intestinal manifestations of IBD.

AIM

To review drug-related dermatological manifestations associated with immunosuppressive and anti-tumour necrosis factor (anti-TNF) therapy.

METHODS

The literature was searched on PubMed for dermatological adverse events in IBD.

RESULTS

Present thiopurine exposure was associated with a 5.9-fold [95% confidence interval (CI), 2.1-16.4] increased risk of developing non-melanoma skin cancer (NMSC). The peak incidence is highest in Caucasians over the age of 65 years with crude incidence rates of 4.0 and 5.7/1000 patient-years for present and previous use. In anti-TNF-exposed subjects, drug-induced lupus was reported in 1% of the cases and a psoriatic rash in up to 3% of the cases. Anti-TNF monotherapy increases the risk of NMSC ~2-fold to a rate of 0.5 cases per 1000 person-years. Cutaneous lymphomas have been rarely reported in subjects on thiopurine or anti-TNF drug monotherapy. Combination therapy seems to have an additive effect on the risk of developing NMSC and lymphoma.

CONCLUSIONS

Physicians need to be aware of the wide spectrum of dermatological complications of immunosuppressive and anti-TNF therapy in IBD, especially psoriasis and non-melanoma skin cancer. Vigilance and regular screening for non-melanoma skin cancer is recommended. Case discussions between gastroenterologists and dermatologists should be undertaken to best manage dermatological adverse events.

Pharmacokinetics of tofacitinib, a janus kinase inhibitor, in patients with impaired renal function and end-stage renal disease

The pharmacokinetics (PK) of tofacitinib were assessed in patients with mild (Cockcroft-Gault creatinine clearance >50 and ≤80 mL/min), moderate (≥30 and ≤50 mL/min), and severe (<30 mL/min) renal impairment, and end-stage renal disease (ESRD) requiring dialysis. Six patients each with normal, mild, moderate, or severely impaired renal function, and 12 patients with ESRD, received single tofacitinib doses of 10 mg. PK data were obtained from blood and dialyzate (patients with ESRD only) samples prior and subsequent to dosing and/or hemodialysis (patients with ESRD only). Relative to patients with normal renal function, mean (90% CI) AUC(0-∞) ratios were 137% (97-195), 143% (101-202), and 223% (157-316) in patients with mild, moderate, and severe renal impairment, respectively. Maximum plasma concentrations (Cmax ) were similar across the four treatment groups. Terminal phase half-life (t1/2 ) increased with severity of renal impairment. Mean AUC(0-∞) in patients with ESRD on a non-dialysis day was similar to that in patients with moderate renal impairment and approximately 40% greater than healthy volunteer data. Mean (SD) dialyzer efficiency (ratio of dialyzer clearance/blood flow entering the dialyzer) was 0.73 (0.15). However, due to extensive non-renal clearance, dialysis procedure is unlikely to result in significant elimination of tofacitinib.

Tofacitinib in kidney transplantation

INTRODUCTION

This review will discuss the mechanism of action and important kidney transplant clinical trial data for the small molecule Janus kinase (JAK) 3 inhibitor tofacitinib , formerly known as CP-690,550 and tasocitinib.

AREAS COVERED

Successful kidney transplantation requires adequate immunosuppression. Current maintenance immunosuppressive protocols which rely on calcineurin inhibitors have long-term nephrotoxicity and negative impact on cardiometabolic risk factors. JAKs are cytoplasmic tyrosine kinases that participate in the signaling of a broad range of cell surface receptors, particularly members of the cytokine receptor common gamma (cγ) chain family. JAK3 inhibition has immunosuppressive effects and treatment with tofacitinib in clinical trials has demonstrated efficacy in autoimmune disorders such as psoriasis and rheumatoid arthritis. Nonhuman primate models of renal transplantation demonstrated prolonged graft survival with tofacitinib compared to control. Renal transplant clinical trials in humans have demonstrated tofacitinib to be noninferior to cyclosporine in terms of rejection rates and graft survival. There was also a lower rate of new onset diabetes after transplant. However, there was a trend toward more infections, including cytomegalovirus and BK virus nephritis.

EXPERT OPINION

Tofacitinib may be a promising alternative to calcineurin inhibitors. The optimal therapeutic window is still being determined.

Report of the second joint meeting of ESOT and AST: current pipelines in biotech and pharma

Following the first joint meeting organized by the European (ESOT) and American (AST) Societies of Transplantation in 2010, a second joint meeting was held in Nice, France, on October 12-14, 2012 at the Palais de la Mediterannee. Co-chairs of the scientific advisory committee were Dr. Flavio Vincenti (AST) and Dr. Teun Van Gelder (ESOT). The goal was to discuss the key unmet needs in solid organ transplantation with the opportunity to interrelate current basic research efforts with clinical translation. Thus, the topic of this second meeting "Transformational therapies and diagnostics in transplantation" was devised and a summary of this meeting follows.

Is it time to give up with calcineurin inhibitors in kidney transplantation?

Calcineurin inhibitors (CNIs) represent today a cornerstone for the maintenance immunosuppressive treatment in solid organ transplantation. Nevertheless, several attempts have been made either to minimize their dosage or to avoid CNIs at all because these drugs have the severe side effect of chronic nephrotoxicity. This issue represents a frontier for renal transplantation. The principal problem is to understanding whether the poor outcome over the long-term may be ascribed to CNIs nephrotoxicity or to the inability of these drugs to control the acute and chronic rejection B cells mediated. The authors analyze extensively all the international trials attempting to withdraw, minimize or avoid the use of CNIs. Few trials undertaken in low risk patients with an early conversion from CNIs to proliferation signal inhibitors were successful, but the vast majority of trials failed to improve CNIs side effects. To date the use of a new drug, a co-stimulation blocker, seems promising in avoiding CNIs with similar efficacy, better glomerular filtration rate and an improved metabolic profile. Moreover the use of this drug is not associated with the development of donor-specific anti-human leukocyte antigen antibodies. This point has a particular relevance, because the failure of CNIs to realize good outcomes in renal transplantation has recently ascribed to their inability to control the acute and chronic rejections B-cell mediated. This paper analyzes all the recent studies that have been done on this issue that represents the real frontier that should be overcome to realize better results over the long-term after transplantation.

Targeting kinases: a new approach to treating inflammatory rheumatic diseases

After two decades of research and development activity focussed on orally active kinase inhibitors, the first such drug (the JAK inhibitor Xeljanz, tofacitinib) was approved by the FDA in November 2012 for the treatment of rheumatoid arthritis (RA). There is an intense activity in many companies both on expanding the utility of JAK inhibitors in other auto-immune indications and in discovering inhibitors of the JAK family with different and more selective profiles. Progress is also being made with orally active Syk inhibitors. One such inhibitor (fostamatinib) is currently in large-scale phase 3 trials, and there are others in clinical development. The last two to three years have been transformative for kinase inhibitors in auto-immune diseases, as several inhibitors have finally progressed beyond phase 2 trials after so many failures on other targets. Thus, there are new treatment options for RA patients beyond existing oral DMARDs and parenteral biologics.

Back to the future: oral targeted therapy for RA and other autoimmune diseases

The molecular biology revolution coupled with the development of monoclonal antibody technology enabled remarkable progress in rheumatology therapy, comprising an array of highly effective biologic agents. With advances in understanding of the molecular nature of immune cell receptors came elucidation of intracellular signalling pathways downstream of these receptors. These discoveries raise the question of whether selective targeting of key intracellular factors with small molecules would add to the rheumatologic armamentarium. In this Review, we discuss several examples of this therapeutic strategy that seem to be successful, and consider their implications for the future of immune-targeted treatments. We focus on kinase inhibitors, primarily those targeting Janus kinase family members and spleen tyrosine kinase, given their advanced status in clinical development and application. We also summarize other targets involved in signalling pathways that might offer promise for therapeutic intervention in the future.

Phospho-specific flow cytometry for pharmacodynamic monitoring of immunosuppressive therapy in transplantation

Organ transplant recipients frequently suffer from toxicity or from lack of efficacy of immunosuppressive drugs, which can be attributed to individual variations in drug sensitivity. This problem can be resolved by applying pharmacodynamic monitoring that focuses on measuring the biological effects of drugs. Here we discuss the new technique called phospho-specific flow cytometry to monitor the activity of intracellular immune signaling pathways at the single-cell level in whole blood samples. Through this tool the efficacy of immunosuppressive medication can be assessed, novel targets can be identified, and differences in drug sensitivity between cells and patients can be clarified.