Mercaptopurine for the treatment of ulcerative colitis - a randomised placebo-controlled trial

BACKGROUND AND AIMS

Scepticism about the efficacy of thiopurines for ulcerative colitis (UC) is rising.This study aimed to evaluate mercaptopurine treatment for UC.

METHODS

In this prospective, randomised, double-blind, placebo-controlled trial, patients with active UC, despite treatment with 5-aminosalicylates (5-ASA), were randomised for therapeutic drug monitoring (TDM)-guided mercaptopurine treatment or placebo for 52 weeks. Corticosteroids were given in the first eight weeks and 5-ASA was continued. Proactive metabolite-based mercaptopurine and placebo dose adjustments were applied from week six onwards by unblinded clinicians. The primary endpoint was corticosteroid-free clinical remission and endoscopic improvement (total Mayo score ≤2 points and no item >1) at week 52 in an intention-to-treat analysis.

RESULTS

Between December 2016 and April 2021, 70 patients were screened and 59 were randomised at six centres. In the mercaptopurine group, 16/29 (55.2%) patients completed the 52-week study, compared to 13/30 (43.3%) on placebo. The primary endpoint was achieved by 14/29 (48.3%) patients on mercaptopurine and 3/30 (10%) receiving placebo (Δ=38.3%, 95% CI 17.1-59.4, p=0.002). Adverse events occurred more frequently with mercaptopurine (808.8 per 100 patient years) compared to placebo (501.4 per 100 patient years). Five serious adverse events occurred; four on mercaptopurine and one on placebo. TDM-based dose adjustments were executed in 22/29 (75.9%) patients, leading to lower mercaptopurine doses at week 52 compared to baseline.

CONCLUSIONS

Optimised mercaptopurine treatment was superior to placebo in achieving clinical, endoscopic and histological outcomes at one year following corticosteroid induction treatment in UC patients. More adverse events occurred in the mercaptopurine group.

Thioguanine is effective as maintenance therapy for inflammatory bowel disease: a prospective multicentre registry study

BACKGROUND AND AIMS

Thioguanine is a well-tolerated and effective therapy for inflammatory bowel disease (IBD) patients. Prospective, effectiveness data are needed to substantiate the role of thioguanine as a maintenance therapy for IBD.

METHODS

IBD patients, who previously failed azathioprine or mercaptopurine, and initiated thioguanine were prospectively followed for 12 months starting when corticosteroid-free clinical remission was achieved (HBI ≤ 4 or SCCAI ≤ 2). Primary endpoint was corticosteroid-free clinical remission throughout 12 months. Loss of clinical remission was defined as SCCAI > 2 or HBI > 4, need of surgery, escalation of therapy, initiation of corticosteroids or study discontinuation. Additional endpoints were adverse events, drug survival, physician global assessment (PGA) and quality of life (QoL).

RESULTS

Sustained corticosteroid-free clinical remission at month 3, 6 or 12 months was observed in 75 (69%), 66 (61%) and 49 (45%) of 108 patients, respectively. Thioguanine was continued in 86 patients (80%) for at least 12 months. Loss of response (55%) included escalation to biologicals in 15%, corticosteroids in 10% and surgery in 3%. According to PGA scores, 82% of patients were still in remission after 12 months and QoL scores remained stable. Adverse events leading to discontinuation were reported in 11%, infections in 10%, myelo- and hepatotoxicity each in 6% and portal hypertension in 1% of patients.

CONCLUSION

Sustained corticosteroid-free clinical remission over 12 months was achieved in 45% of IBD patients on monotherapy with thioguanine. A drug continuation rate of 80%, together with favourable PGA and QoL scores, underlines the tolerability and effectiveness of thioguanine for IBD.

Minimisation of dissipated energy in the airways during mechanical ventilation by using constant inspiratory and expiratory flows - Flow-controlled ventilation (FCV)

It has been suggested that energy dissipation in the airways during mechanical ventilation is associated with an increased probability of ventilator induced lung injury (VILI). We hypothesise that energy dissipation in the airways may be minimised by ventilating with constant flow during both the inspiration and expiration phases of the respiratory cycle. We present a simple analysis and numerical calculations that support our hypothesis and show that for ventilation with minimum dissipated energy not only should the flows during inspiration and expiration be controlled to be constant and continuous, but the ventilation should also be undertaken with an I:E ratio that is close to 1:1.