Sample Size and Data Monitoring for Clinical Trials With Extremely Low Incidence Rates

AbstractVarious approaches are considered for adjustment of clinical trial size for patient noncompliance. Such approaches either model the effect of noncompliance through comparison of two survival distributions or two simple proportions. Models that allow for variation of noncompliance and event rates between time intervals are also considered. The approach that models the noncompliance adjustment on the basis of survival functions is conservative and hence requires larger sample size. The model to be selected for noncompliance adjustment depends upon available estimates of noncompliance and event rate patterns.

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TBE in Italy

Tick-borne encephalitis - The Book ◽

10.33442/26613980_12b15-3 ◽

2020 ◽

Keyword(s):

Surveillance System ◽

Ad Hoc ◽

National Level ◽

Case Series ◽

Incidence Rates ◽

Mountainous Regions ◽

North East ◽

The North ◽

Tick Borne Encephalitis ◽

Low Incidence

Italy is considered a low-incidence country for tick-borne encephalitis (TBE) in Europe.1 Areas at higher risk for TBE in Italy are geographically clustered in the forested and mountainous regions and provinces in the north east part of the country, as suggested by TBE case series published over the last decade.2-5 A national enhanced surveillance system for TBE has been established since 2017.6 Before this, information on the occurrence of TBE cases at the national level in Italy was lacking. Both incidence rates and the geographical distribution of the disease were mostly inferred from endemic areas where surveillance was already in place, ad hoc studies and international literature.1

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Adverse events of special interest in clinical trials of rheumatoid arthritis, psoriatic arthritis, ulcerative colitis and psoriasis with 37 066 patient-years of tofacitinib exposure

RMD Open ◽

10.1136/rmdopen-2021-001595 ◽

2021 ◽

Vol 7 (2) ◽

pp. e001595

Author(s):

Gerd R Burmester ◽

Peter Nash ◽

Bruce E Sands ◽

Kim Papp ◽

Lori Stockert ◽

...

Keyword(s):

Rheumatoid Arthritis ◽

Ulcerative Colitis ◽

Clinical Trials ◽

Psoriatic Arthritis ◽

Adverse Events ◽

Special Interest ◽

Phase 1 ◽

Incidence Rates ◽

Study Data ◽

System Organ Class

ObjectivesTo analyse adverse events (AEs) of special interest across tofacitinib clinical programmes in rheumatoid arthritis (RA), psoriatic arthritis (PsA), ulcerative colitis (UC) and psoriasis (PsO), and to determine whether the incidence rates (IRs; unique patients with events per 100 patient-years) of these events are consistent across diseases.MethodsThe analysis included data from patients exposed to ≥1 dose of tofacitinib in phase 1, 2, 3 or 3b/4 clinical trials and long-term extension (LTE) studies (38 trials) in RA (23 trials), PsA (3 trials), UC (5 trials) and PsO (7 trials). All studies were completed by or before July 2019, except for one ongoing UC LTE study (data cut-off May 2019). IRs were obtained for AEs of special interest.Results13 567 patients were included in the analysis (RA: n=7964; PsA: n=783; UC: n=1157; PsO: n=3663), representing 37 066 patient-years of exposure. Maximum duration of exposure was 10.5 years (RA). AEs within the ‘infections and infestations’ System Organ Class were the most common in all diseases. Among AEs of special interest, IRs were highest for herpes zoster (non-serious and serious; 3.6, 1.8, 3.5 and 2.4 for RA, PsA, UC and PsO, respectively) and serious infections (2.5, 1.2, 1.7 and 1.3 for RA, PsA, UC and PsO, respectively). Age-adjusted and sex-adjusted mortality ratios (weighted for country) were ≤0.2 across cohorts.ConclusionsThe tofacitinib safety profile in this analysis was generally consistent across diseases and with longer term follow-up compared with previous analyses.

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