Nasal

In the nasal arm of the substudy, the assay could quantify a dosing-dependent increase in vector-specific DNA in 15 out of 15 active-dose subjects post treatment, although in four of these modest levels of DNA were detected prior to dosing. In the placebo patients, DNA could also be detected in samples from three out of four subjects post dosing (none prior to dosing); no vector-specific mRNA was quantifiable in either group.

Lower airway

In the bronchial arm of the substudy, the assay quantified vector-specific DNA in 10 out of 10 active-treatment patients and zero out of seven placebo subjects post dosing (Figure 30); no vector-specific mRNA was quantifiable in either group.

FIGURE 30

Assessment of DNA from bronchial brushings in the placebo (n = 7) and active-treatment (n = 10) subgroups. Each circle represents an individual patient.

Nasal

The nasal arm comprised 24 patients in the ITT group, 20 of whom were in the PP. One patient had a mean total chloride secretory response ≥ 5 mV pre-dosing and was, therefore, excluded as prespecified in the protocol. Day 28 post-treatment recordings for two active-treatment patients had to be delayed beyond a window of > 7 days of the prespecified interval and were therefore excluded; both patients had usable values at the day 14 post treatment time point. Overall, 75 out of 106 (70.8%) of zero chloride, and 70 out of 106 (66.0%) of isoproterenol recordings were interpretable.

There were no significant changes in baseline values or amiloride responses in either the placebo or active-treatment groups. No significant changes in either the zero chloride or isoproterenol responses were seen. For the zero chloride component 10 out of 14 active-treatment patients and three out of six placebo patients showed net secretion (i.e. a more negative value post treatment than pretreatment); 4 out of 14 active-treatment patients showed mean pre–post-treatment responses (ranging from –3.4 mV to –7.0 mV), which were more negative than the largest placebo response. For the isoproterenol component, 11 out of 12 active-treatment patients and three out of six placebo patients showed net secretion (Figure 31).

FIGURE 31

The response of the nasal epithelium to perfusion with (a) a zero chloride solution; and (b) a zero chloride solution containing isoproterenol (10 µM). Each symbol indicates the change in this response from trial start to finish for the (more...)

Bronchial

In the bronchial subgroup, one active-treatment patient withdrew after six doses, but consented to post-dosing bronchoscopy within the prespecified timing (28 ± 5 days) after the last dose; values for this patient are included in the analysis. Post-dosing bronchoscopy was performed on two placebo patients 58 and 62 days after their last doses, and on two active-treatment patients 49 and 111 days after their last dose. The data for the two placebo patients are included in the final analysis, on the basis that the natural history of bronchial electrophysiology is unlikely to be influenced by a dose of saline approximately 60 days previously. Values for the two active-treatment patients were omitted from the final analysis given the monthly dosing schedule in the trial based on previously generated gene expression data, although their samples were included in the safety analysis. Overall, 66 out of 102 (64.7%) recordings fulfilled the acceptability criteria.

There were no significant changes in basal values in either the placebo or active-treatment groups. Figure 32 shows bronchial chloride responses using the mean of all available interpretable tracings for each patient; a negative value indicates a non-CF direction. The placebo group (n = 7) had a median pre–post trial change of +3.1 mV (range +9.3 to –1.2 mV) and the active-treatment group (n = 10) –1.3 mV (range +4.0 to –5.8 mV) (p = 0.032). Five out of 10 active-treatment patients had values more negative than the largest placebo response. Figure 32b shows the same analysis with only the most negative value recorded for each patient at any time point. The placebo group showed a median pre–post trial change of +2.6 mV (range +9.3 to –1.2 mV) and the active group –2.8 mV (range + 4.0 to –16.8 mV) (p = 0.087). Six out of 10 active-treatment patients had values more negative than the largest placebo response.

FIGURE 32

Change from pretreatment in the response of the bronchial epithelium to perfusion with a zero chloride solution containing isoproterenol (10 µM). (a) The response of the bronchial epithelium to perfusion with a zero chloride solution containing isoproterenol (more...)