Abnormal Appearance of the Area Centralis in Labrador Retrievers With an ABCA4 Loss-of-function Mutation.

PURPOSE: To study retinal appearance and morphology in Labrador retrievers (LRs) heterozygous and homozygous for an ABCA4 loss-of-function mutation. METHODS: Ophthalmic examination, including ophthalmoscopy and simple testing of vision, was performed in five ABCA4wt/wt, four ABCA4wt/InsC, and six ABCA4InsC/InsC LRs. Retinas were also examined with confocal scanning laser ophthalmoscopy (cSLO) and optical coherence tomography (OCT). Infrared and fundus autofluorescence (FAF) images were studied, and outer nuclear layer (ONL) and neuroretinal thickness were measured in the central and peripheral area centralis. RESULTS: Clinical signs in young ABCA4InsC/InsC LRs were subtle, whereas ophthalmoscopic findings and signs of visual impairment were obvious in old ABCA4InsC/InsC LRs. Retinal appearance and vision testing was unremarkable in heterozygous LRs regardless of age. The cSLO/OCT showed abnormal morphology including ONL thinning, abnormal outer retinal layer segmentation, and focal loss of retinal pigment epithelium in the fovea equivalent in juvenile ABCA4InsC/InsC LRs. The abnormal appearance extended into the area centralis and visual streak in middle-aged ABCA4InsC/InsC and then spread more peripherally. A mild phenotype was seen on cSLO/OCT and FAF in middle-aged to old ABCA4wt/InsC LRs. CONCLUSIONS: Abnormal appearance and morphology in the fovea equivalent are present in juvenile ABCA4InsC/InsC. In the older affected LRs, the visual streak and then the peripheral retina also develop an abnormal appearance. Vision deteriorates slowly, but some vision is retained throughout life. Older heterozygotes may show a mild retinal phenotype but no obvious visual impairment. The ABCA4InsC/InsC LR is a potential model for ABCA4-mediated retinopathies/juvenile-onset Stargardt disease in a species with human-sized eyes. TRANSLATIONAL RELEVANCE: The ABCA4InsC mutation causes juvenile-onset abnormal appearance of the fovea equivalent in affected dogs that slowly spreads in the retina, while only a mild phenotype is seen in older carriers. This is the first non-primate, large-animal model for ABCA4-related/STGD1 retinopathies in a species with a fovea equivalent.

First-line afatinib for advanced EGFRm+ NSCLC: Analysis of long-term responders in the LUX-Lung 3, 6, and 7 trials.

OBJECTIVES: In patients with advanced epidermal growth factor receptor mutation-positive (EGFRm+) non-small cell lung cancer (NSCLC), first-line afatinib significantly improved progression-free survival (PFS) and objective response vs. platinum-doublet chemotherapy in the phase III LUX-Lung 3 and LUX-Lung 6 trials, and significantly improved PFS, time to treatment failure and objective response vs. gefitinib in the phase IIb LUX-Lung 7 trial. We report post-hoc analyses of efficacy, safety and patient-reported outcomes (PROs) in afatinib long-term responders (LTRs) in these trials. METHODS: Treatment-naïve patients with stage IIIB/IV EGFRm + NSCLC randomized to afatinib in LUX-Lung 3/LUX-Lung 6/LUX-Lung 7 were included in the analysis. Patients treated with afatinib for ≥ 3 years were defined as LTRs. RESULTS: In LUX-Lung 3, LUX-Lung 6, and LUX-Lung 7, 24/229 (10%), 23/239 (10%) and 19/160 (12%) afatinib-treated patients were LTRs. Baseline characteristics were similar to the study populations, except for the proportions of women (LUX-Lung 3/LUX-Lung 6 only; 92/78% vs. 64% overall) and Del19-positive patients (63-79% vs. 49-58% overall). Median treatment duration among LTRs was 50, 56 and 42 months, and median PFS was 49.5, 55.5, and 42.2 months in LUX-Lung 3/LUX-Lung 6/LUX-Lung 7, respectively. Median overall survival could not be estimated. Frequency of afatinib dose reduction was consistent with the LUX-Lung 3/LUX-Lung 6/LUX-Lung 7 overall populations. PROs were stable in LTRs, with slight improvements after 3 years of afatinib treatment vs. baseline scores. CONCLUSIONS: In the LUX-Lung 3/LUX-Lung 6/LUX-Lung 7 trials, 10-12% of afatinib-treated patients were LTRs. Long-term afatinib treatment was independent of tolerability-guided dose adjustment and had no detrimental impact on safety or PROs.

Is progression-free survival associated with a better health-related quality of life in patients with lung cancer? Evidence from two randomised trials with afatinib.

OBJECTIVE: Progression-free survival (PFS) is frequently used as an efficacy end point in oncology clinical trials. However, there is limited evidence to support a positive association between improvement in PFS and improvement in health-related quality of life (HRQoL). The association between PFS and HRQoL was evaluated in two randomised trials. MATERIALS AND METHODS: Data from two randomised controlled trials in patients with non-small cell lung cancer (NSCLC; LUX-Lung 1 and LUX-Lung 3) were used to investigate HRQoL in patients to determine whether tumour progression is accompanied by worsening HRQoL. HRQoL was assessed using the cancer-specific European Organization for Research and Treatment of Cancer (EORTC) core questionnaire QLQ-C30, the EuroQol EQ-5D overall utility and EuroQol EQ visual analogue scale. In both studies, progression was evaluated by independent review using RECIST criteria (primary end point) and also by investigator assessment. The relationship between tumour progression and HRQoL was evaluated using analysis of covariance and a longitudinal model. RESULTS: Compliance with HRQoL questionnaire completion was high. In both studies, patients with progression consistently experienced numerically poorer HRQoL at the time of progression than patients without progression. Differences in mean scores were statistically significant (p<0.05) between patients with and without progression at week 4 in all analyses in LUX-Lung 1 and at multiple time points in LUX-Lung 3. Results from the longitudinal analysis showed that progression (by independent review and investigator assessment) appears to have consistent negative impact on all three HRQoL measures (all p<0.0001). CONCLUSIONS: Tumour progression in patients with NSCLC was associated with statistically significant worsening in HRQoL. These findings confirm the value of PFS as a patient-relevant end point.

Analysis of duration of response in oncology trials.

The fraction of patients who respond to treatment and the duration of response in the subset of responding patients are commonly evaluated in oncology trials of cytotoxic compounds. While formal, comparative analysis of the fraction of patients responding to treatment is straightforward in a randomised trial, analyses that attempt to compare treatments in terms of the duration of response in responding patients are likely to be biased since the groups being compared are defined by the post-treatment outcome of response rather than by randomisation. Subsets of responding patients may not be comparable with respect to baseline prognostic factors and, consequently, formal comparative analysis is discouraged by the European Medicines Evaluation Agency. In an attempt to combine both the fraction of patients responding to treatment and the duration of response in responding patients, Temkin considered the probability of being in response function (PBRF) as a description of the treatment difference. Begg and Larson subsequently developed a parametric version of the PBRF under the exponential assumption. This paper briefly considers the PBRF as a means of estimating the expected duration of response across all randomised patients, thereby allowing a formal and unbiased comparison of treatments for duration of response. Building on earlier work, a more general and flexible approach to estimating the expected duration of response is offered to generalize beyond the exponential distribution.