Active Comparator: Extension Phase

Important information about the Active Comparator Study

  • This study was designed and funded by Gilead Sciences, Inc. (GSI) with input from all authors on this publication. Some of the authors had consultancy with or were employees and/or shareholders of GSI
  • The results and conclusions of this single study should be interpreted in light of its limitations, including, but not limited to, the open-label design and inclusion of previously treated patients with inhaled tobramycin (TNS). A comparable study has not been conducted to verify these results
  • There are conflicting views regarding the validation of the Cystic Fibrosis Questionnaire-Revised (CFQ-R). The FDA determined that the CFQ-R was not validated in accordance with its final Guidance for Industry: Patient-Reported Outcome Measures: Use in Medical Product Development to Support Labeling Claims4
  • All results from the extension phase of the Active Comparator Trial are exploratory and therefore caution should be taken when interpreting the results

Active Comparator Extension Phase: Study Design8

The open-label Active Comparator period of the study was followed by an optional 24-week, open-label, single-arm extension period of 3 CAYSTON treatment cycles.

All patients who participated in the extension phase of the Active Comparator Study were treated with CAYSTON*

CAYSTON Superiority analysis: Adjusted mean actual change (SE) in FEV% across 3 treatment cycles

*Eligible patients for the extension phase were from European study sites only (n=133; patients continuing CAYSTON from active comparator phase: 68; patients starting CAYSTON after TNS in active comparator phase: 65).

Active Comparator Extension Phase: Efficacy Results8

Study Extension Phase: Percent Change in FEV1% Predicted from Week 0

CAYSTON Non-inferiority analysis: Mean relative change in FEV% at Day 28

In this open-label study, standard error bars are for graphical representation of variability, and inferences regarding statistical significance should not be made.

Active Comparator Extension Phase: Adverse Reactions8

Adverse events occurring during the extension period8

  • Severe adverse events were experienced by 15/133 (11.3%) patients, most commonly cough (n=7/133), productive cough (n=5/133), and pyrexia (n=5/133)
  • One life-threatening event was reported (lung infiltration unrelated to treatment)
  • Two patients died due to complications of CF disease; both deaths were considered unrelated to treatment
  • Adverse events considered by investigators as treatment-related were reported for 6.8% of patients (n=9/133), most commonly respiratory incidents (n=6/133)
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