A phase 3, double-blind, parallel-group study to evaluate the efficacy and safety of tezacaftor in combination with ivacaftor in participants 6 through 11 years of age with cystic fibrosis homozygous for F508del or heterozygous for the F508del-CFTR mutation and a residual function mutation

BACKGROUND

The CFTR modulator tezacaftor/ivacaftor was efficacious and generally safe and well tolerated in Phase 3 studies in participants ≥12 years of age with cystic fibrosis (CF) homozygous for the F508del-CFTR mutation or heterozygous with a residual function-CFTR mutation (F/F or F/RF respectively). We evaluated tezacaftor/ivacaftor's efficacy and safety over 8 weeks in participants 6 through 11 years of age with these mutations.

METHODS

Participants were randomized 4:1 to tezacaftor/ivacaftor or a blinding group (placebo for F/F, ivacaftor for F/RF). The primary endpoint was within-group change from baseline in the lung clearance index 2·5 (LCI_2·5) through Week 8. Secondary endpoints were change from baseline in sweat chloride (SwCl), cystic fibrosis questionnaire-revised (CFQ-R) respiratory domain score, and safety.

RESULTS

Sixty-seven participants received at least one study drug dose. Of those, 54 received tezacaftor/ivacaftor (F/F, 42; F/RF, 12), 10 placebo, and 3 ivacaftor; 66 completed the study. The within-group change in LCI_2·5 was significantly reduced (improved) by -0·51 (95% CI: -0·74, -0·29). SwCl concentration decreased (improved) by -12·3 mmol/L and CFQ-R respiratory domain score increased (improved, nonsignificantly) by 2·3 points. There were no serious adverse events (AEs) or AEs leading to tezacaftor/ivacaftor discontinuation or interruption. The most common AEs (≥10%) in participants receiving tezacaftor/ivacaftor were cough, headache, and productive cough.

CONCLUSIONS

Tezacaftor/ivacaftor improved lung function (assessed using LCI) and CFTR function (measured by SwCl concentration) in participants 6 through 11 years of age with F/F or F/RF genotypes. Tezacaftor/ivacaftor was safe and well tolerated; no new safety concerns were identified.

Evaluation of a multiple breath nitrogen washout system in children

INTRODUCTION

The multiple breath nitrogen washout (MBW) test offers a sensitive measure of airway function. In this study we aim to (a) assess the validity of the EasyOne Pro LAB (MBW_ndd ) in an in vitro lung model, (b) assess the feasibility, repeatability, and reproducibility of MBW_ndd and (c) compare outcomes with the Exhalyzer D (MBW_EM ) and body plethysmography.

METHODS

In vitro, functional residual capacity (FRC) measurements were assessed using a lung model under quasi-physiological conditions and compared to measured FRC. In vivo plethysmography and MBW were performed in a prospective study of children at two visits (n = 45 healthy; n = 41 cystic fibrosis [CF]). Bland-Altman plots were used to compare agreement between FRC and lung clearance index (LCI) measurements.

RESULTS

In vitro FRC_ndd measurements were repeatable but lung volumes were underestimated (mean relative difference -5.4% (limits of agreement [LA] -9.6%; -1.1%), 95% confidence interval (CI) -6.27; -4.45). In vivo, compared to plethysmography, FRC_ndd was consistently lower (-19.3% [-40.5; 1.9], 95% CI [-23.9; -14.7]), and showed a volume dependency. LCI_ndd values were also higher in children with smaller lung volumes. The within-test coefficient of variation of the FRC_ndd and LCI_ndd were 4.9% in health, and 5.6% and 6.9% in CF respectively. LCI_ndd was reproducible between-visits (mean relative difference [LA] -3.7% [-14.8, -7.5; 95% CI -6.6; -0.73] in health [n = 17] and 0.34% [-13.2, 22.8; 95% CI -5.0; 5.69] in CF [n = 23]). When calculated using the same algorithm, LCI_ndd was similar to LCI_EM in health.

CONCLUSIONS

MBW_ndd measurements are feasible, repeatable, and reproducible, however, MBW-derived outcomes are not interchangeable with MBW_EM .

MSTO1 mutations cause mtDNA depletion, manifesting as muscular dystrophy with cerebellar involvement

MSTO1 encodes a cytosolic mitochondrial fusion protein, misato homolog 1 or MSTO1. While the full genotype–phenotype spectrum remains to be explored, pathogenic variants in MSTO1 have recently been reported in a small number of patients presenting with a phenotype of cerebellar ataxia, congenital muscle involvement with histologic findings ranging from myopathic to dystrophic and pigmentary retinopathy. The proposed underlying pathogenic mechanism of MSTO1-related disease is suggestive of impaired mitochondrial fusion secondary to a loss of function of MSTO1. Disorders of mitochondrial fusion and fission have been shown to also lead to mitochondrial DNA (mtDNA) depletion, linking them to the mtDNA depletion syndromes, a clinically and genetically diverse class of mitochondrial diseases characterized by a reduction of cellular mtDNA content. However, the consequences of pathogenic variants in MSTO1 on mtDNA maintenance remain poorly understood. We present extensive phenotypic and genetic data from 12 independent families, including 15 new patients harbouring a broad array of bi-allelic MSTO1 pathogenic variants, and we provide functional characterization from seven MSTO1-related disease patient fibroblasts. Bi-allelic loss-of-function variants in MSTO1 manifest clinically with a remarkably consistent phenotype of childhood-onset muscular dystrophy, corticospinal tract dysfunction and early-onset non-progressive cerebellar atrophy. MSTO1 protein was not detectable in the cultured fibroblasts of all seven patients evaluated, suggesting that pathogenic variants result in a loss of protein expression and/or affect protein stability. Consistent with impaired mitochondrial fusion, mitochondrial networks in fibroblasts were found to be fragmented. Furthermore, all fibroblasts were found to have depletion of mtDNA ranging from 30 to 70% along with alterations to mtDNA nucleoids. Our data corroborate the role of MSTO1 as a mitochondrial fusion protein and highlight a previously unrecognized link to mtDNA regulation. As impaired mitochondrial fusion is a recognized cause of mtDNA depletion syndromes, this novel link to mtDNA depletion in patient fibroblasts suggests that MSTO1-deficiency should also be considered a mtDNA depletion syndrome. Thus, we provide mechanistic insight into the disease pathogenesis associated with MSTO1 mutations and further define the clinical spectrum and the natural history of MSTO1-related disease.

Evaluation of the BAX® System for Detection of Salmonella in Selected Foods: Collaborative Study

A multilaboratory study was conducted to compare the automated BAX® System to the standard cultural methods for detection of Salmonella in selected foods. Five food types—frankfurters, raw ground beef, mozzarella cheese, raw frozen tilapia fish, and orange juice—at 3 inoculation levels, were analyzed by each method. A sixth food type, raw ground chicken, was tested using 3 naturally contaminated lots. A total of 16 laboratories representing government and industry participated. In this study, 1386 samples were analyzed, of which 1188 were paired samples and 198 were unpaired samples. Of the 1188 paired samples, 461 were positive by both methods and 404 were negative by both methods. Thirty-seven samples were positive by the BAX System but negative by the standard reference method, and 11 samples were positive by standard cultural method and negative by the BAX System. Of the 198 unpaired samples, 106 were positive by the BAX System and 60 were positive by the standard cultural method. A Chi square analysis of each of the 6 food types, at the 3 inoculation levels tested, was performed. For all foods, the BAX System demonstrated results comparable to those of the standard reference methods based on the Chi square results.

Patient-Reported Outcome Measures Among Breast Cancer Survivors in Malaysia: A Comparative Study With Patients From High-Income Countries

Background: Patient-reported outcome measures (PROMs) are essential for identifying how patients perceive the outcomes of their cancer treatment, and is the ultimate success of cancer care. Although a growing number of studies have focused on PROMs in high income countries (HICs), outcomes relevant to patients in developing countries are less understood. Furthermore, the lack of standardization in PROMs makes it difficult to interpret these data for research or quality monitoring. Aim: In this study, we compared the results of PROM measures between patients in Malaysia, a middle income country, and those in HICs, using standard PROMs questionnaires. We also explored the differences in perceived importance of patient reported outcomes within the multiracial Malaysian cohort. Methods: Breast cancer patients (n=1063) were recruited in hospitals serving suburban areas of Malaysia. Of these, 969 patients were eligible for analysis. The surveys were conducted through face-to-face interviews (68%) or were self-administered (30%). An outcome was considered important if it was scored between 7-9 on a 9-point Likert scale. We compared PROMs scores between Malaysian patients and data previously collected from patients in HICs using logistic regression models, adjusting for demographic and clinical characteristics. A two-step cluster analysis was conducted to explore differences in the perceived importance of PROMs between clusters of Malaysian patients. Results: Compared with 1777 patients from HICs, Malaysian patients were less likely to rate overall and recurrence free survival, as well as emotional, cognitive, social and sexual functioning as very important outcomes. Interestingly, more Malaysian women reported that pain (50% vs. 39%), breast symptoms (51% vs. 35%), and major complications (60% vs. 44%) were very important outcomes ( P < 0.001). Compared with young, married Malaysian women, the cluster of older married women (mean age of 57 vs. 52), who were less likely to have received breast reconstructive surgery (8.6% vs. 16.8%), was more likely to rate sexual functioning (32.8% vs. 25.0%, P = 0.036), body image (63.9% vs. 42.4%, P < 0.001), and satisfaction with the breast (50.7% vs. 37.0%, P = 0.011) as very important outcomes. Conclusion: The differences in breast cancer patient needs between and within populations should be considered carefully to better clinician-patient relationship, patient care and satisfaction and assess the outcomes of our cancer care. Future research is needed to find suitable targeted interventions to identify and address the diverse needs of breast cancer patients in low and middle income countries.

Genetic characterisation of molecular targets in carcinoma of unknown primary

BACKGROUND

Carcinoma of unknown primary (CUP) is a metastatic epithelial malignancy in the absence of an identifiable primary tumour. Prognosis for patients with CUP is poor because treatment options are generally limited to broad spectrum chemotherapy. A shift towards personalised cancer management based on mutation profiling offers the possibility of new treatment paradigms. This study has explored whether actionable, oncogenic driver mutations are present in CUP that have potential to better inform treatment decisions.

METHODS

Carcinoma of unknown primary cases (n = 21) were selected and DNA was isolated from formalin-fixed paraffin embedded sections prior to amplification and sequencing. Two distinct yet complementary targeted gene panels were used to assess variants in up to 76 known cancer-related genes for the identification of biologically relevant and actionable mutations.

RESULTS

Variants were detected in 17/21 cases (81%) of which 11 (52%) were potentially actionable with drugs currently approved for use in known primary cancer types or undergoing clinical trials. The most common variants detected were in TP53 (47%), KRAS (12%), MET (12%) and MYC (12%). Differences at the molecular level were seen between common CUP histological subtypes. CUP adenocarcinomas and poorly differentiated carcinomas harboured the highest frequency of variants in genes involved in signal transduction pathways (e.g. MET, EGFR, HRAS, KRAS, and BRAF). In contrast, squamous cell carcinoma exhibited a higher frequency of variants in cell cycle control and DNA repair genes (e.g. TP53, CDKN2A and MLH1).

CONCLUSION

Taken together, mutations in biologically relevant genes were detected in the vast majority of CUP tumours, of which half provided a potentially novel treatment option not generally considered in CUP.

Systematic review of the impact of breast-conserving surgery on cancer outcomes of multiple ipsilateral breast cancers

Background

The clinical effectiveness of treating ipsilateral multifocal (MF) and multicentric (MC) breast cancers using breast‐conserving surgery (BCS) compared with the standard of mastectomy is uncertain. Inconsistencies relate to definitions, incidence, staging and intertumoral heterogeneity. The primary aim of this systematic review was to compare clinical outcomes after BCS versus mastectomy for MF and MC cancers, collectively defined as multiple ipsilateral breast cancers (MIBC).

Methods

Comprehensive electronic searches were undertaken to identify complete papers published in English between May 1988 and July 2015, primarily comparing clinical outcomes of BCS and mastectomy for MIBC. All study designs were included, and studies were appraised critically using the Newcastle–Ottawa Scale. The characteristics and results of identified studies were summarized.

Results

Twenty‐four retrospective studies were included in the review: 17 comparative studies and seven case series. They included 3537 women with MIBC undergoing BCS; breast cancers were defined as MF in 2677 women, MC in 292, and reported as MIBC in 568. Six studies evaluated MIBC treated by BCS or mastectomy, with locoregional recurrence (LRR) rates of 2–23 per cent after BCS at median follow‐up of 59·5 (i.q.r. 56–81) months. BCS and mastectomy showed apparently equivalent rates of LRR (risk ratio 0·94, 95 per cent c.i. 0·65 to 1·36). Thirteen studies compared BCS in women with MIBC versus those with unifocal cancers, reporting LRR rates of 2–40 per cent after BCS at a median follow‐up of 64 (i.q.r. 57–73) months. One high‐quality study reported 10‐year actuarial LRR rates of 5·5 per cent for BCS in 300 women versus 6·5 per cent for mastectomy among 887 women.

Conclusion

The available studies were mainly of moderate quality, historical and underpowered, with limited follow‐up and biased case selection favouring BCS rather than mastectomy for low‐risk patients. The evidence was inconclusive, weakening support for the St Gallen consensus and supporting a future randomized trial.

Abstract P6-12-01: Can exercise influence survival following breast cancer? Evidence from randomised, controlled trials

Background: The Exercise for Health (EfH) trials were randomized, controlled trials designed to evaluate an 8-month pragmatic, exercise intervention, commencing 6 weeks post-surgery for women with newly diagnosed breast cancer residing in urban- or rural/regional areas. Outcomes for these exploratory analyses were overall survival (OS), breast cancer-specific survival (BCS) and disease-free survival (DFS). Methods: Consenting urban-residing women (EfH 1, n=194) and rural/regional-residing women (EfH 2, n=143) were randomized to exercise or usual care. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for OS, BCS and DFS (exercise group, n=207, 65% urban women; usual care group, n=130, 46% urban women), with and without adjustment for prognostic factors including trial (urban/rural), age, body mass index, disease stage and presence of comorbidities. Further exploratory subgroup analyses were also conducted to assess whether effect on OS, BCS and DFS differed according to prognostic variables. Results: After a median follow-up of 8.3 years (IQR: 8.0-8.7 years) there were 11 (5.3%) deaths in the exercise group compared with 15 (11.5%) deaths in the usual care group (Table 1).

Table 1 Overall, breast cancer-specific and disease-free survival events by group allocation. All patientsUsual careExercise n=337n = 130n = 207 n (%)n (%)n (%)Breast cancer-related deaths20 (5.9)10 (7.7)10 (4.8)Non-breast cancer-related deaths6 (1.8)5 (3.8)1 (0.5)Overall survival events26 (7.7)15 (11.5)11 (5.3)Recurrence of breast cancer20 (5.9)8 (6.2)12 (5.8)Alive at follow-up9 (2.7)3 (2.3)6 (4.6)Deceased by follow-up11 (3.3)5 (3.1)6 (4.6)New primary breast cancer13 (3.9)5 (3.8)8 (3.9)Alive at follow-up13 (3.9)5 (3.8)8 (6.2)Deceased by follow-up0 (0.0)0 (0.0)0 (0.0)Disease-free survival events*48 (14.2)23 (17.7)25 (12.1)* Disease-free survival events include recurrence of breast cancer, new primary breast cancers, and all-cause deaths. Note that women who had recurrence and died before follow-up only count once towards disease-free survival events.

HRs for the exercise group were: OS: 0.45, 95% CI=0.20-0.96; p=0.04; BCS: 0.61, 95% CI=0.25-1.46, p=0.26; and DFS: 0.66, 95% CI=0.38-1.17; p=0.16 (adjusted analyses yielded similar results). With the exception of BCS for those with a body mass index &gt;30, all HRs for subgroup analyses favored exercise, with effect on OS for women of younger age (&lt;55), those with stage II+ disease, and those with 1+ comorbidity at baseline significant (p&lt;0.05). Effect of exercise on DFS was also significant (p&lt;0.05) for urban women. Conclusion: Findings suggest that an individually-prescribed and monitored exercise program integrated during and beyond treatment for breast cancer, and that was designed to cater for all women, irrespective of place of residence and access to health services, has clear potential to influence survival.

Citation Format: Hayes SC, Steele M, Spence R, Gordon L, Battistutta D, Bashford J, Pyke C, Saunders C, Eakin E. Can exercise influence survival following breast cancer? Evidence from randomised, controlled trials [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-12-01.

Exercise following breast cancer: exploratory survival analyses of two randomised, controlled trials

PURPOSE

The Exercise for Health trials were randomised, controlled trials designed to evaluate an 8-month pragmatic exercise intervention, commencing 6 weeks post-surgery for women with newly diagnosed breast cancer residing in urban or rural/regional Australia. For these exploratory analyses, the primary and secondary outcomes were overall survival (OS) and disease-free survival (DFS), respectively.

METHODS

Consenting urban- (n = 194) and rural/regional-residing women (n = 143) were randomised to exercise (intervention delivered face-to-face or by telephone) or usual care. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CI) for survival outcomes (exercise group, n = 207, 65% urban women; usual care group, n = 130, 46% urban women).

RESULTS

After a median follow-up of 8.3 years, there were 11 (5.3%) deaths in the exercise group compared with 15 (11.5%) deaths in the usual care group (OS HR for the exercise group: 0.45, 95% CI 0.20-0.96; p = 0.04). DFS events for the exercise versus usual care group were 25 (12.1%) and 23 (17.7%), respectively (HR: 0.66, 95% CI 0.38-1.17; p = 0.16). HRs for OS favoured exercise irrespective of age, body mass index, stage of disease, intervention compliance, and physical activity levels at 12 months post-diagnosis, although were stronger (p < 0.05) for younger women, women with stage II + disease, women with 1 + comorbidity at time of diagnosis, higher intervention compliance and for those who met national physical activity guidelines at 12 months post-diagnosis.

CONCLUSION

An exercise intervention delivered during and beyond treatment for breast cancer, and that was designed to cater for all women irrespective of place of residence and access to health services, has clear potential to benefit survival. Trial numbers: ACT RN: 012606000233527; ACT RN: 12609000809235.

Developments in multiple breath washout testing in children with cystic fibrosis

BACKGROUND

Lung clearance index (LCI) is becoming recognized as an important addition in the monitoring of pediatric cystic fibrosis (CF). The non-invasive technique is easy to perform in all ages, reproducible and increasingly being used in clinical trials. There is interest in utilizing it within the clinic setting but its current use is mostly as a research tool. The procedure is highly dependent on skilled operators and a relaxed testing environment is key to obtaining good quality measurements.

CONCLUSIONS

Standardization of LCI is part of an ongoing collaborative, multicenter process. This review describes the background to LCI, discusses technical issues and limitations and provides examples of its utility in clinical and research contexts.