OP0127 TRANSCRIPTIONAL ACTIVITY OF SURVIVIN CONTRIBUTES TO MATURATION AND FUNCTION OF THE INTERFERON-GAMMA PRODUCING T CELLS IN RHEUMATOID ARTHRITIS

Background:

Interferon gamma (IFNg) signalling and downstream effects make important contribution in pathogenesis of rheumatoid arthritis (RA). Here, we propose a mechanism by which oncoprotein survivin participates in development of IFN-dependent repertoire of T cells in RA patients.

Objectives:

We study the role of survivin in the phenotype of CD4 T cells of RA patients.

Methods:

CD4 cells of RA patients and healthy controls were purified from blood, activated and subjected to RNAseq, ChIPseq with antibodies to survivin (BIRC5) was performed on CD4+ cells. Histone H3 ChIPseq was performed using antibodies to H3K27ac, H3K27me3 and H3K4me3. Statistical analysis was performed In R-studio using the Bioconductor package DESeq2, clustering using Spearman and Ward.D2.

Results:

Unsupervised clustering of CD4 samples by expression of 48 core Th cell markers identified subsets of CD28hiCD27hiIFNnegcentral memory cells (Tcm), CD28loCD27loIFNloeffector memory cells (Tem) and CD28nullCD27nullIFNhiterminal effector cells (Tte). Tte cells showed classical features of Th1 cells including high levels of TBX21, TNFa and IL32 and signs of activation in IFN signalling machinery. Interestingly, they combined the features of peripheral Tregs CD25hiFoxp3hiIKZF2negand IL10 producing cells together with type 1 regulatory cells, which rely on transcription factors BATF and IRF1 for the differentiation and produced high amounts of perforin and granzyme B. Importantly, Tte CD4 cells had also high transcription of BIRC5 (p=1.15e-18).

To study if BIRC5 is a part of IFN signalling, CD4 cells were cultured with survivin inhibitor YM155 and activated with IFNg. RNAseq analysis revealed 2033 (FC<2.0, n=336) differentially expressed genes in the IFN stimulated cultures. Interestingly, a substantial number of these IFN-dependent genes was significantly reduced in the survivin-deficient cultures and included among others CD28, FoxP3, IKZF2, ICOS, BATF, PRDM1, CXCR3, IRF4 and IRF8. Analysis of the peak sequences identified enrichment for composite motifs for IRFs (ETS:IRF, p1.0e-124; bZIP:IRF, p=1.0e-640), indicating that survivin is important for IFNg signalling. Numerically, the peaks containing ETS:IRF motifs were most prevalent and identified in total within 49.7% of all survivin-ChIP peaks. Frequent was co-localisation of the IRF:bZIP and IRF:ETS motifs within the survivin peaks. Among the IRF motifs dominated those suitable for IRF1 (p=1,0e-127) and IRF8 (p=1,0e-84). However, the DNA binding motifs of these two are alike.

Encouraged by the survivin ChIPseq results, we wanted to know its relation to histone marks. We observed that 50% of survivin peaks containing both IRF:bZIP and IRF:ETS motifs are co-localized with the H3K27ac marks. In total, 16 of 48 core Th cell markers used for patients clustering were identified by survivin ChIPseq, co-localized with IRF composite motifs and histone marks. They were also dependent of survivin for expression.

Conclusion:

his study showed that survivin binds to DNA and regulates the core gene expression contributing to maturation and function of the IFNg producing Th1 cells.

References:

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Disclosure of Interests:

Malin Erlandsson: None declared, Karin ME Andersson: None declared, Nisha Nair: None declared, Anastasius Damdimopoulos: None declared, Sofia Töyrä Silfverswärd: None declared, Rille Pullerits: None declared, Anne Barton Consultant of: AbbVie, Maria I Bokarewa: None declared

THU0005 VARIABILITY OF DNA METHYLATION IS A DRIVER OF LYMPHOCYTE DYSREGULATION IN EARLY RHEUMATOID ARTHRITIS

Background:

DNA methylation patterns differ between leukocyte subsets and mediate the impact of environmental exposures on the molecular and functional phenotype of immune cells. Besides differences in mean methylation of CpG positions amongst patients with immune mediated diseases, recent evidence indicates variability of site-specific DNA methylation also contributes to pathogenesis1,2.

Objectives:

To seek evidence of altered DNA methylation patterns in RA, controlling for systemic inflammation and immunotherapy use.

Methods:

Patients with confirmed clinical diagnoses were enrolled from the Northeast Early Arthritis Cohort (NEAC). CD4+and CD19+lymphocytes were isolated from fresh blood by positive selection prior to therapeutic immune modulation. Methylation was quantified in cell subset-specific DNA (Infinium MethylationEPIC BeadChip, Illumina)3. Differentially methylated positions and regions (DMPs, DMRs) between RA and non-RA patients were identified (linear modelling, filtering on 5% pairwise difference in mean DNA methylation, and DMRcate package). Next, to identify instances where methylation variance differed between comparator groups, Bartlett’s test was performed using the iEVORA package, which accounts for outlier values4. Findings were controlled for technical confounders and subject to multiple test correction (FDR). A validated hypergeometric test was used to annotate enriched pathways.

Results:

After sample- and probe-level quality control, CD4+ and B lymphocyte specific data were respectively available for 45 and 49 RA patients, and 64 and 81 disease controls matched for systemic inflammation (CRP, ESR). No DMPs were identified in either cell type at FDR < 0.05 and Δβ ≥0.05. Only following relaxation of multiple test correction was it possible to identify DMRs in either cell type, most notably encapsulating 10 CpGs relatively hypomethylated at the promoter of the endosome protein-encodingRUFY1gene in CD4+ lymphocytes of RA patients (Δβ = 0.076). By contrast, striking evidence for differential variation in DNA methylation was observed at 291 and 601 CpGs of CD4+ and B lymphocytes, respectively (exemplars depicted in Figure 1). Only 15 of these differentially variable positions (DVPs) were common to both cell types. Pathway analysis highlighted potential functional consequences of DVP associations; for example, RA-specific hypervariability implicates prostaglandinsignalling in CD4+ lymphocytes.

Conclusion:

We highlight a role for altered variability in DNA methylation during the molecular pathogenesis of RA, and emphasise the importance of its study in relevant cell subsets.

References:

[1]Paul DSet al. Nature Communications 7, 13555 doi: 10.1038/ncomms13555 (2016).

[2]Webster AP et al. Genome Medicine 10, 64 (2018)doi:10.1186/s13073-018-0575-9.

[3]Clark AD et al. Journal of Allergy and Clinical Immunology 2019; doi: 10.1016/j.jaci.2019.12.910

[4]Teschendorff AE et al. Nature Communications 2016; 7:12.

Disclosure of Interests:

Alexander Clark: None declared, Najib Naamane: None declared, Nisha Nair: None declared, Amy Anderson: None declared, Nishanthi Thalayasingam: None declared, Julie Diboll: None declared, Anne Barton Consultant of: AbbVie, Stephen Eyre: None declared, John D Isaacs Consultant of: AbbVie, Bristol-Myers Squibb, Eli Lilly, Gilead, Janssen, Merck, Pfizer, Roche, Louise Reynard: None declared, Arthur Pratt Grant/research support from: Pfizer, GlaxoSmithKlein

THU0022 DIFFERENTIAL DNA METHYLATION AS A PREDICTOR OF TOCILIZUMAB RESPONSE IN RHEUMATOID ARTHRITIS PATIENTS

Background:

Tocilizumab (TCZ) is a biological disease-modifying antirheumatic drug that blocks IL-6 signalling and is effective in ameliorating disease activity in rheumatoid arthritis (RA). However, approximately 50% of patients do not respond adequately to TCZ and some patients report adverse events. Considering there is growing evidence that DNA methylation is implicated in RA susceptibility and response to some biologics (1, 2), we investigated DNA methylation as a candidate biomarker for response to TCZ in RA.

Objectives:

To identify differential DNA methylation signatures in whole blood associated with TCZ response in patients with RA.

Methods:

Epigenome-wide DNA methylation patterns were measured using the Infinium EPIC BeadChip (Illumina) in whole blood-derived DNA samples from patients with RA. DNA was extracted from blood samples taken pre-treatment and following 3 months on therapy, and response was determined at 6 months using the Clinical Disease Activity Index (CDAI). Patients who had good response (n=10) or poor response (n=10) to TCZ by 6 months were selected. Samples from secondary poor responders (n=10) (patients who had an improvement of CDAI and were in remission at 3 months, followed by a worsening of CDAI at 6 months) were also analysed. Differentially methylated positions and regions (DMPs/DMRs) were identified using linear regression, adjusting for gender, age, cell composition, smoking status, and glucocorticoid use. Gene Set Enrichment Analysis (GSEA) was used to identify significant pathways associated with response and Functional Epigenetic Module analysis of interactome hotspots in regions of differential methylation.

Results:

20 DMPs were significantly associated with response status at 6 months in the pre-treatment samples. Another 21 DMPs were associated with response in the 3 month samples. Within good responders, 10 DMPs showed significant change in methylation level between pre-treatment and the 3 month samples (unadjusted P-value <10-6). One DMP, cg03121467, was significantly less methylated in good responders compared to poor responders in the pre-treatment samples. This DMP is close toEPB41L4Aand thought to have a role in β–catenin signalling. GSEA of DMRs in non- and secondary non- responders identified histone acetyltransferase pathways and included theKAT2Agene, which is a repressor of NF-κB. Additional analysis of interaction hotspots of differential methylation identified significant interactions withSTAMBPandPTPN12associated with response status.

Conclusion:

These preliminary results provide evidence that DNA methylation patterns may predict response to TCZ. Validation of these findings in other larger data sets is required.

References:

[1]Liu,Y., Aryee,M.J., Padyukov,L., Fallin,M.D., Hesselberg,E., Runarsson,A., Reinius,L., Acevedo,N., Taub,M., Ronninger,M.,et al.(2013) Epigenome-wide association data implicate DNA methylation as an intermediary of genetic risk in rheumatoid arthritis.Nat. Biotechnol.,31, 142–147.

[2]Plant,D., Webster,A., Nair,N., Oliver,J., Smith,S.L., Eyre,S., Hyrich,K.L., Wilson,A.G., Morgan,A.W., Isaacs,J.D.,et al.(2016) Differential Methylation as a Biomarker of Response to Etanercept in Patients With Rheumatoid Arthritis.Arthritis Rheumatol. (Hoboken, N.J.),68, 1353–60.

Disclosure of Interests:

Nisha Nair: None declared, Darren Plant: None declared, John Isaacs Consultant of: AbbVie, Bristol-Myers Squibb, Eli Lilly, Gilead, Janssen, Merck, Pfizer, Roche, Ann Morgan Grant/research support from: I have received a grant from Roche Products Ltd to establish a registry for GCA patients treated with tocilizumab., Consultant of: I have undertaken consultancy work for Roche, Chugai, Regeneron, Sanofi and GSK in the area of GCA therapeutics., Speakers bureau: I have presented on tocilizumab therapy for GCA and glucocorticoid toxicity on behalf of Roche products ltd., Kimme Hyrich Grant/research support from: Pfizer, UCB, BMS, Speakers bureau: Abbvie, Anne Barton Consultant of: AbbVie, Anthony G Wilson: None declared

0501 Development and Initial Evaluation of Web-Based Cognitive Behavioral Therapy for Insomnia “Nitecapp” in Rural Dementia Caregivers: A Mixed-Methods Study

Introduction

Informal caregivers (CGs) of persons with dementia frequently experience insomnia. The time consuming and unpredictable schedule of CGs, and associated emotional/physical exhaustion emphasize the need for brief, easily accessible interventions to treat insomnia. Internet-based behavioral insomnia interventions hold promise, particularly for rural CGs who have limited access to traditional in-person treatments. This study aimed to 1) translate an efficacious 4 session cognitive behavioral therapy for insomnia (CBT-I) to web-based “NiteCAPP” for dementia caregivers, and 2) conduct NiteCAPP usability testing/evaluate acceptability of content and features.

Methods

NiteCAPP is an online CBT-I that incorporates guided delivery through weekly therapist moderator feedback. A stepwise approach was implemented in order to explore user needs and validate NiteCAPP content in a focus group of rural dementia caregivers (n=5) and primary care providers (PCPs; n=5). Participants conducted usability testing and provided ratings of program content (1-least favorable to 5-most favorable) regarding ease of use, amount of information, website maintaining interest, adequate font size, videos maintaining interest/easy to understand/helpful. Participants also indicated whether they had at home internet access, method of internet access, and provided open ended feedback on NiteCAPP. Feedback transcripts were compiled and analyzed independently (C.S.M., A.F.C.) through deductive content analysis. Topics mentioned frequently were categorized and merged into common themes during consensus meeting, and NiteCAPP was subsequently adapted.

Results

Average ratings for NiteCAPP features were high, ranging from 4.1/5 to 4.7/5 across all items. All participants had access to internet through both phone and computer. No barriers to use identified. Feedback themes were largely positive (e.g., comprehensive written material, promotes independence, excellent visual tools for therapy moderator feedback, good pacing, use of visual contrast). Negative themes for improvement/adaptation included adding font size options, a light/dark mode, tab with all videos, reducing amount of scrolling, adding a glossary of terms.

Conclusion

Rural dementia CGs and PCPs evaluated NiteCAPP as easy to use with acceptable features and program content and no barriers to access. Improvement themes were used to adapt NiteCAPP. Next steps are to evaluate feasibility and preliminary efficacy of NiteCAPP in rural dementia CGs with insomnia.

Support

none

Health gains, costs and cost-effectiveness of a population-based screening programme for abdominal aortic aneurysms

BACKGROUND

Abdominal aortic aneurysm (AAA) rupture carries a high fatality rate. AAAs can be detected before rupture by abdominal ultrasound imaging, allowing elective repair. Population-based screening for AAA in older men reduces AAA-related mortality by about 40 per cent. The UK began an AAA screening programme offering one-off scans to men aged 65 years in 2009. Sweden has a similar programme. Currently, there is no AAA screening programme in New Zealand. This cost-utility analysis aimed to assess the cost-effectiveness of a UK-style screening programme in the New Zealand setting.

METHODS

The analysis compared a formal AAA screening programme (one-off abdominal ultrasound imaging for about 20 000 men aged 65 years in 2011) with no systematic screening. A Markov macrosimulation model was adapted to estimate the health gains (in quality-adjusted life-years, QALYs), health system costs and cost-effectiveness in New Zealand. A health system perspective and lifetime horizon was adopted.

RESULTS

With New Zealand-specific inputs, the adapted model produced an estimate of about NZ $15 300 (€7746) per QALY gained, with a 95 per cent uncertainty interval (UI) of NZ $8700 to 31 000 (€4405 to 15 694) per QALY gained. Health gains were estimated at 117 (95 per cent UI 53 to 212) QALYs. Health system costs were NZ $1·68 million (€850 535), with a 95 per cent UI of NZ $820 200 to 3·24 million (€415 243 to €1·65 million).

CONCLUSION

Using New Zealand's gross domestic product per capita (about NZ $45 000 or €22 100) as a cost-effectiveness threshold, a UK-style AAA screening programme would be cost-effective in New Zealand.

Abstract P5-14-07: Accuracy of psychosocial assessments in an online surgical decision aid developed for early breast cancer patients with resource and educational constraints

Background: Women with early breast cancer routinely face a choice between breast conservation therapy and mastectomy, and assume agency through shared decision making. However, for women with lower socioeconomic power or education, barriers such as access to understandable information, involvement of family in decision making, and a decreased sense of autonomy inhibits this agency. To better empower this population, a simple to understand, online, self-administered, conjoint analysis based decision aid called “Navya Patient Preference Tool” (PPT) is developed to be used outside the physician encounter. PPT is unique in its incorporation of several psychological scales that assess potential confounders of participation in shared decision making.

Methodology: This is a pre-planned analysis of the reliability and validity of the psychological scales used in all three arms of an IRB approved randomized controlled trial to assess PPT. Women with operable node negative breast cancer eligible for BCT or MRM at one of Asia's largest academic tertiary cancer centers were eligible. PPT trial consists of an initial conjoint analysis questionnaire analyzing implicit preferences for breast conservation given to the intervention arms. The following psychological scales were given to all patients regardless of randomization: Autonomy Preference Index (API), Traditional-Egalitarian Gender Roles (TEGR), Caregiving Role, Brief Resiliency Scale (BRS), Appearances Scale, and Decisional Conflict Scale (DCS). Cronbach's alpha as a measure of internal reliability for all scales, and correlations of scores with known demographic trends as a measure of external validity are calculated.

Results: Of the 102 patients enrolled, 30 completed PPT in English, 39 in Hindi, and 33 in Marathi, (vernaculars). 69/102 were in middle and lower socioeconomic groups (Kuppuswamy Index). 53/102 had completed less than high school education. Internal reliability of all scales were high, with Cronbach's alpha above 0.7: API 0.74, TEGR 0.78, Caregiving 0.7, BRS 0.7, Appearance 0.84. DCS was highly reliable at 0.91, and is the primary outcome measure for the RCT. Correlations in the dataset met those expected in real world data, suggesting external validity. For e.g., education was inversely correlated with traditional gender roles on TEGR (R -0.4, p &lt;0.01), and positively correlated with resilience on BRS (R 0.228, p &lt;0.05). Individual scale items that are unrealistic were not chosen by any of the 102 respondents (e.g.,. My doctor should not participate in my medical decisions), substantiating nuanced reading. 85% of patients “Strongly Agreed” on a 1-5 Likert scale that “The survey questions were easy to understand” (mean score 1.18/5. SD 0.4).

Conclusions: Women with limited education and low socioeconomic status complete the online, self administered PPT outside of a physician encounter, with high internal reliability and external validity. Decision Aids such as Navya PPT, which account for psychosocial confounders of agency, have the potential to benefit women otherwise marginalized from shared decision making.

Citation Format: Joshi S, Ramarajan L, Ramarajan N, Srivastava G, Begum F, Deshpande O, Tondare A, Nair N, Parmar V, Gupta S, Badwe RA. Accuracy of psychosocial assessments in an online surgical decision aid developed for early breast cancer patients with resource and educational constraints [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-14-07.

More Robust Monitoring for Continuous Quality Improvement in Screening Programmes

Background and context: The National Screening Unit in the Ministry of Health is responsible for the safety, effectiveness, and quality of five formal screening programs in New Zealand: breast screening, cervical screening, bowel screening, newborn metabolic screening, and newborn hearing screening. Currently, each screening program has a set of standards against which performance is assessed. Each program is monitored through a range of avenues: formally reported indicators, audits, contract reporting, case reviews, etc. Aim: We aimed to review the existing monitoring across all the screening programs to: (a) Clarify what existing measures served what purpose, and for which audience (b) Review what was being captured through different monitoring avenues, to assess gaps and duplications (c) To better align our monitoring approach across all the screening programs. Strategy/Tactics: For each measure, we used a formal template to justify its existence, covering multiple aspects including rationale, lifespan, dimension of quality, screening pathway step, targets and associated evidence, thresholds for corrective action, and “owner” responsible for triggering quality improvement. We also mapped the screening program standards to various monitoring avenues to assess gaps and duplications. Program/Policy process: This process was timed to coincide with the need for developing monitoring for a new screening program (bowel screening), and revising monitoring for an established screening program undergoing a change (cervical screening switching to HPV testing as a primary screen). Outcomes: *anticipated outcomes in italics, will be completed by time of Congress* This process resulted in an overarching monitoring framework, which functions as a blueprint for screening-program-specific monitoring plans. What was learned: Screening programs have different monitoring requirements depending on what phase they are in (i.e., new versus changing versus established). Having clearly documented rationale ensures that every measure is justified and has an “evidence trail”. Having clearly documented audiences, thresholds and responsibilities for corrective action ensures that monitoring contributes to continuous quality improvement, rather than monitoring for monitoring's sake.

Abstract P4-10-02: Validation of a clinical informatics system for online multidisciplinary expert opinions: Mapping treatment recommendations to the NCCN resource-Stratified framework

Background: Most cancer patients in Low and Middle Income Countries (LMIC) cannot afford effective, expensive, evidence based therapies. Therefore, oncologists must tailor treatment plans to individual resource constraints. To support this, NCCN has created a Resource-Stratified Framework® (NCCN-RSF), which is an evidence-based four-tier prioritization scheme. Further, only a fraction of patients in LMIC have ready access to oncologists. In India, there are only ˜1600 oncologists for 1.8 million patients. To bridge this gap, Navya's clinical informatics based mobile ExpertApp combines learning from evidence, prior tumor board decisions, patient resource constraints, and quick review from TMC NCG oncologists to recommend tailored treatment plans to patients via an online expert opinion service. 11865 patients in 22 LMIC have reached out to receive an online expert opinion through Navya (ASCO 2017). This study maps Navya to NCCN-RSF as an evidence-based index for resource-sensitive treatment selection.

Methods: All breast cancer patients who received an online expert opinion from TMC NCG Navya between July 1st 2014 and April 30th 2017 were included. Navya systematically gathered information on patient resource constraints (such as affordability for Trastuzumab). Navya recommendations (breast and nodal surgery, radiation site and fractionation, drug and dose density etc.) were mapped to NCCN-RSF resource tiers (Basic, Core, Enhanced, Parent guideline). Reasons were categorized for Navya recommendations not present in NCCN-RSF.

Results: 616 patients (36.3% metastatic), mostly from India, received 1203 recommendations. At the specific treatment protocol level, 88.3% of Navya recommendations mapped with at least one NCCN-RSF resource tier (Table 1). 78.5% mapped to the Enhanced tier. Only 8.6% of recommendations mapped to Parent guidelines, and did not require tailoring for resource constraints. Fewer than 2% recommendations mapped to Core and none to Basic. 11.7% recommendations were not present in NCCN-RSF, for minor reasons such as substitution of a drug within the same class (35.8%) (e.g., Epirubicin for Adriamycin), dose dense protocols (14.3%) (e.g., 3 weekly Paclitaxel vs weekly Paclitaxel), and recommending Trastuzumab for less than a year for patients unable to afford year long therapy (14.3%), currently not included in NCCN-RSF.

Table 1- Mapping Navya to NCCN RSFNCCN RSF TiersHIGH LEVEL: Multimodality treatment and sequencing (1203)INTERMEDIATE: Within modality treatment categories (1188)GRANULAR: Specific treatment protocols (1140)E.g.Neoadjuvant vs Adjuvant ChemoAnthracycline vs TaxaneHypofractionation vs Standard XRTAt least one Tier98.8%±0.696%±1.188.3%±2Enhanced94.4%±1.391%±1.778.5%±2.7Core1.9%±5.61.2%±5.71.2%±5.8Parent NCCN2.4%±5.63.8%±5.68.6%±5.5

Conclusion: Navya's treatment recommendations are sensitive to resource constraints and map to peer reviewed and evidence based NCCN RSF, primarily at the Enhanced tier. Navya's clinical informatics based online service scales access to resource constrained treatment selection for large numbers of patients in LMIC without easy access to oncologists.

Citation Format: Badwe RA, Gupta S, Feldman N, Pramesh CS, Ramarajan N, Srivastava G, Nair N, Anderson BO. Validation of a clinical informatics system for online multidisciplinary expert opinions: Mapping treatment recommendations to the NCCN resource-Stratified framework [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 P4-10-02.

Tezacaftor-Ivacaftor in Residual-Function Heterozygotes with Cystic Fibrosis

BACKGROUND

Cystic fibrosis is an autosomal recessive disease caused by mutations in the CFTR gene that lead to progressive respiratory decline. Some mutant CFTR proteins show residual function and respond to the CFTR potentiator ivacaftor in vitro, whereas ivacaftor alone does not restore activity to Phe508del mutant CFTR.

METHODS

We conducted a randomized, double-blind, placebo-controlled, phase 3, crossover trial to evaluate the efficacy and safety of ivacaftor alone or in combination with tezacaftor, a CFTR corrector, in 248 patients 12 years of age or older who had cystic fibrosis and were heterozygous for the Phe508del mutation and a CFTR mutation associated with residual CFTR function. Patients were randomly assigned to one of six sequences, each involving two 8-week intervention periods separated by an 8-week washout period. They received tezacaftor-ivacaftor, ivacaftor monotherapy, or placebo. The primary end point was the absolute change in the percentage of predicted forced expiratory volume in 1 second (FEV₁) from the baseline value to the average of the week 4 and week 8 measurements in each intervention period.

RESULTS

The number of analyzed intervention periods was 162 for tezacaftor-ivacaftor, 157 for ivacaftor alone, and 162 for placebo. The least-squares mean difference versus placebo with respect to the absolute change in the percentage of predicted FEV₁ was 6.8 percentage points for tezacaftor-ivacaftor and 4.7 percentage points for ivacaftor alone (P<0.001 for both comparisons). Scores on the respiratory domain of the Cystic Fibrosis Questionnaire-Revised, a quality-of-life measure, also significantly favored the active-treatment groups. The incidence of adverse events was similar across intervention groups; most events were mild or moderate in severity, with no discontinuations of the trial regimen due to adverse events for tezacaftor-ivacaftor and few for ivacaftor alone (1% of patients) and placebo (<1%).

CONCLUSIONS

CFTR modulator therapy with tezacaftor-ivacaftor or ivacaftor alone was efficacious in patients with cystic fibrosis who were heterozygous for the Phe508del deletion and a CFTR residual-function mutation. (Funded by Vertex Pharmaceuticals and others; EXPAND ClinicalTrials.gov number, NCT02392234 .).