The HSP90-MYC-CDK9 network drives therapeutic resistance in mantle cell lymphoma

Brexucabtagene autoleucel CAR-T therapy is highly efficacious in overcoming resistance to Bruton's tyrosine kinase inhibitors (BTKi) in mantle cell lymphoma. However, many patients relapse post CAR-T therapy with dismal outcomes. To dissect the underlying mechanisms of sequential resistance to BTKi and CAR-T therapy, we performed single-cell RNA sequencing analysis for 66 samples from 25 patients treated with BTKi and/or CAR-T therapy and conducted in-depth bioinformatics™ analysis. Our analysis revealed that MYC activity progressively increased with sequential resistance. HSP90AB1 (Heat shock protein 90 alpha family class B member 1), a MYC target, was identified as early driver of CAR-T resistance. CDK9 (Cyclin-dependent kinase 9), another MYC target, was significantly upregulated in Dual-R samples. Both HSP90AB1 and CDK9 expression were correlated with MYC activity levels. Pharmaceutical co-targeting of HSP90 and CDK9 synergistically diminished MYC activity, leading to potent anti-MCL activity. Collectively, our study revealed that HSP90-MYC-CDK9 network is the primary driving force of therapeutic resistance.

Potentiation of apoptosis in drug-resistant mantle cell lymphoma cells by MCL-1 inhibitor involves downregulation of inhibitor of apoptosis proteins

Bruton's tyrosine kinase inhibitors (BTKi) and CAR T-cell therapy have demonstrated tremendous clinical benefits in mantle cell lymphoma (MCL) patients, but intrinsic or acquired resistance inevitably develops. In this study, we assessed the efficacy of the highly potent and selective MCL-1 inhibitor AZD5991 in various therapy-resistant MCL cell models. AZD5991 markedly induced apoptosis in these cells. In addition to liberating BAK from the antiapoptotic MCL-1/BAK complex for the subsequent apoptosis cascade, AZD5991 downregulated inhibitor of apoptosis proteins (IAPs) through a BAK-dependent mechanism to amplify the apoptotic signal. The combination of AZD5991 with venetoclax enhanced apoptosis and reduced mitochondrial oxygen consumption capacity in MCL cell lines irrespective of their BTKi or venetoclax sensitivity. This combination also dramatically inhibited tumor growth and prolonged mouse survival in two aggressive MCL patient-derived xenograft models. Mechanistically, the augmented cell lethality was accompanied by the synergistic suppression of IAPs. Supporting this notion, the IAP antagonist BV6 induced dramatic apoptosis in resistant MCL cells and sensitized the resistant MCL cells to venetoclax. Our study uncovered another unique route for MCL-1 inhibitor to trigger apoptosis, implying that the pro-apoptotic combination of IAP antagonists and apoptosis inducers could be further exploited for MCL patients with multiple therapeutic resistance.

Cotargeting of BTK and MALT1 overcomes resistance to BTK inhibitors in mantle cell lymphoma

Bruton's tyrosine kinase (BTK) is a proven target in mantle cell lymphoma (MCL), an aggressive subtype of non-Hodgkin lymphoma. However, resistance to BTK inhibitors is a major clinical challenge. We here report that MALT1 is one of the top overexpressed genes in ibrutinib-resistant MCL cells, while expression of CARD11, which is upstream of MALT1, is decreased. MALT1 genetic knockout or inhibition produced dramatic defects in MCL cell growth regardless of ibrutinib sensitivity. Conversely, CARD11-knockout cells showed antitumor effects only in ibrutinib-sensitive cells, suggesting that MALT1 overexpression could drive ibrutinib resistance via bypassing BTK/CARD11 signaling. Additionally, BTK knockdown and MALT1 knockout markedly impaired MCL tumor migration and dissemination, and MALT1 pharmacological inhibition decreased MCL cell viability, adhesion, and migration by suppressing NF-κB, PI3K/AKT/mTOR, and integrin signaling. Importantly, cotargeting MALT1 with safimaltib and BTK with pirtobrutinib induced potent anti-MCL activity in ibrutinib-resistant MCL cell lines and patient-derived xenografts. Therefore, we conclude that MALT1 overexpression associates with resistance to BTK inhibitors in MCL, targeting abnormal MALT1 activity could be a promising therapeutic strategy to overcome BTK inhibitor resistance, and cotargeting of MALT1 and BTK should improve MCL treatment efficacy and durability as well as patient outcomes.

Pirtobrutinib and venetoclax combination overcomes resistance to targeted and CAR Tcell therapy in aggressive mantle cell lymphoma

Not available.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Abstract 3955: Targeting transcription elongation via CDK9 in mantle cell lymphoma patients with dual resistance to BTK inhibition and CAR T therapy

Introduction Clinical relapse following CD19 CAR T therapy after failure to BTK inhibitors (BTKi) is a novel and fast growing medical challenge in treating patients with mantle cell lymphoma (MCL). Thus, developing a novel therapy to overcome this BTKi-CAR T dual resistance (Dual-R) is an urgent need. Our unpublished data revealed MYC targets and cyclin-dependent kinase 9 (CDK9) are highly upregulated in the Dual-R compared to BTKi-R samples. CDK9 is a critical component of the positive transcription elongation factor b (P-TEFb) complex. Its inhibition induces acute decline of short-lived mRNA and proteins, especially MYC and MCL-1, in acute myeloid leukemia and diffuse large B-cell lymphoma. Therefore, we hypothesize that targeting CDK9 may turn off MYC-driven tumor survival and drug resistance. BAY-1251152 is a novel selective CDK9 inhibitor with nanomolar potency. However, whether it has the potential to overcome BTKi-CAR T dual resistance has not been assessed.

Methods To validate the correlation of MYC and CDK9 with drug resistance and clinical outcome, we performed whole transcriptomic profiling using primary patient samples. To assess the in vitro efficacy of BAY-1251152, we performed cell viability assay and cell apoptosis assay using MCL cell lines and primary patient samples and followed up with functional studies. furthermore, we assessed its in vivo efficacy using patient-derived xenograft (PDX) models derived from MCL patients including one with Dual-R.

Results The expression of MYC oncogene associates with ibrutinib resistance and Dual-R, and poor clinical outcome. CDK9 expression does not correlates with ibrutinib resistance but it does associate with Dual-R and poor clinical outcome in CAR T-relapsed patients. CDK9 inhibition by BAY-1251152 is highly potent in anti-MCL activity in MCL cell lines with low nanomolar range of IC50 (59.6-172.3 nM) by inducing robust cell apoptosis. BAY-1251152 induces dose and time-dependent CDK9 inhibition. A rapid decline of phosphorylation of RNA polymerase II, MYC, MCL-1, and Cyclin D1 can be observed as early as 2 hours. Furthermore, BAY-1251152 (10mg/kg, QW) significantly inhibited tumor growth (p = 0.000003) in a PDX model derived from a Dual-R patient without causing apparent toxicity in NSG mice. In addition, BAY-1251152 also significantly suppressed tumor growth in the PDX models derived from a BTKi-R patient (p=0.00015) and a BTKi-venetoclax dual-resistant patient (p=0.009).

Conclusion Our findings showed that targeting CDK9 by its specific inhibitor BAY-1251152 led to potent in vitro anti-MCL activity. BAY-1251152 induces fast CDK9 inhibition and rapid decline of MYC, MCL-1 and Cyclin D1 to induce robust cell death. BAY-1251152 is also potent in inhibiting tumor growth in PDX models. These data support that CDK9 is a promising target to overcome BTKi-CAR T dual resistance in MCL, which is in urgent need.

Citation Format: Vivian Changying Jiang, Lingzhi Li, Alexa Jordan, Yu Xue, Fangfang Yan, Joseph McIntosh, Yang Liu, Yuxuan Che, Yijing Li, Qingsong Cai, Angela Leeming, Lukas Simon, Zhongming Zhao, Jia Zhou, Michael Wang. Targeting transcription elongation via CDK9 in mantle cell lymphoma patients with dual resistance to BTK inhibition and CAR T therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3955.

Targeting FcγRIIB by antagonistic antibody BI-1206 improves the efficacy of rituximab-based therapies in aggressive mantle cell lymphoma

Inevitable relapses remain as the major therapeutic challenge in patients with mantle cell lymphoma (MCL) despite FDA approval of multiple targeted therapies and immunotherapies. Fc gamma receptors (FcγRs) play important roles in regulating antibody-mediated immunity. FcγRIIB, the unique immune-checkpoint inhibitory member of the FcγR family, has been implicated in immune cell desensitization and tumor cell resistance to the anti-CD20 antibody rituximab and other antibody-mediated immunotherapies; however, little is known about its expression and its immune-modulatory function in patients with aggressive MCL, especially those with multi-resistance. In this study, we found that FcγRIIB was ubiquitously expressed in both MCL cell lines and primary patient samples. FcγRIIB expression is significantly higher in CAR T-relapsed patient samples (p < 0.0001) compared to ibrutinib/rituximab-naïve, sensitive or resistant samples. Rituximab-induced CD20 internalization in JeKo-1 cells was completely blocked by concurrent treatment with BI-1206, a recombinant human monoclonal antibody targeting FcγRIIB. Combinational therapies with rituximab-ibrutinib, rituximab-venetoclax and rituximab-CHOP also induced CD20 internalization which was again effectively blocked by BI-1206. BI-1206 significantly enhanced the in vivo anti-MCL efficacy of rituximab-ibrutinib (p = 0.05) and rituximab-venetoclax (p = 0.02), but not the rituximab-CHOP combination in JeKo-1 cell line-derived xenograft models. In patient-derived xenograft (PDX) models, BI-1206, as a single agent, showed high potency (p < 0.0001, compared to vehicle control) in one aggressive PDX model that is resistant to both ibrutinib and venetoclax but sensitive to the combination of rituximab and lenalidomide (the preclinical mimetic of R² therapy). BI-1206 sensitized the efficacy of rituximab monotherapy in a PDX model with triple resistance to rituximab, ibrutinib and CAR T-therapies (p = 0.030). Moreover, BI-1206 significantly enhanced the efficacy of the rituximab-venetoclax combination (p < 0.05), which led to long-term tumor remission in 25% of mice. Altogether, these data support that targeting this new immune-checkpoint blockade enhances the therapeutic activity of rituximab-based regimens in aggressive MCL models with multi-resistance.

United States' experience in nuchal translucency measurement: variation according to provider characteristics in over five million ultrasound examinations

OBJECTIVE

The Nuchal Translucency Quality Review (NTQR) program has provided standardized education, credentialing and epidemiological monitoring of nuchal translucency (NT) measurements since 2005. Our aim was to review the effect on NT measurement of provider characteristics since the program's inception.

METHODS

We evaluated the distribution of NT measurements performed between January 2005 and December 2019, for each of the three primary performance indicators of NT measurement (NT median multiples of the median (MoM), SD of log₁₀ NT MoM and slope of NT with respect to crown-rump length (CRL)) for all providers within the NTQR program with more than 30 paired NT/CRL results. Provider characteristics explored as potential sources of variability included: number of NT ultrasound examinations performed annually (annual scan volume of the provider), duration of participation in the NTQR program, initial credentialing by an alternative pathway, provider type (physician vs sonographer) and number of NT-credentialed providers within the practice (size of practice). Each of these provider characteristics was evaluated for its effect on NT median MoM and geometric mean of the NT median MoM weighted for the number of ultrasound scans, and multiple regression was performed across all variables to control for potential confounders.

RESULTS

Of 5 216 663 NT measurements from 9340 providers at 3319 sites, the majority (75%) of providers had an NT median MoM within the acceptable range of 0.9-1.1 and 85.5% had NT median MoM not statistically significantly outside this range. Provider characteristics associated with measurement within the expected range of performance included higher volume of NT scans performed annually, practice at a site with larger numbers of other NT-credentialed providers, longer duration of participation in the NTQR program and alternative initial credentialing pathway.

CONCLUSIONS

Annual scan volume, duration of participation in the NTQR program, alternative initial credentialing pathway and number of other NT-credentialed providers within the practice are all associated with outcome metrics indicating quality of performance. It is critical that providers participate in ongoing quality assessment of NT measurement to maintain consistency and precision. Ongoing assessment programs with continuous feedback and education are necessary to maintain quality care. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

The antibody drug conjugate VLS-101 targeting ROR1 is effective in CAR T-resistant mantle cell lymphoma

Mantle cell lymphoma (MCL) is a rare, aggressive and incurable subtype of non-Hodgkin’s B-cell lymphoma. The principal barrier is frequent clinical relapse to multiple lines of therapies, including new FDA-approved biologics and cell therapy. Brexucabtagene autoleucel, the first and only FDA approved chimeric antigen receptor (CAR) T product in MCL, demonstrated unprecedented efficacy in overcoming resistance to Bruton’s tyrosine kinase inhibitors. However, relapses have inevitably occurred and once relapsed these patients display a very poor clinical outcome. Currently, there is no optional therapy specifically designed for these patients. The development of tailored and more efficacious therapies is therefore critical and represents a new medical need. We found that while the receptor tyrosine kinase-like orphan receptor 1 (ROR1) is expressed across most of the MCL cells, it is significantly elevated in CAR T-relapsed MCL tumors. To see whether this aberrant ROR1 expression contributed to CAR T resistance, we targeted ROR1 using VLS-101, a monomethyl auristatin E conjugated anti-ROR1 antibody. VLS-101 showed potent anti-MCL activity in vitro in ROR1-expressing MCL cell lines and ex vivo in primary patient samples. Importantly, VLS-101 safely induced tumor regression in PDX models resistant to CAR T-cell therapy, ibrutinib and/or venetoclax. These data advocate for targeting ROR1 as a viable approach in the treatment of ROR1-positive MCL tumors, especially those with failure to prior therapies. These data also provide strong evidence for future enrollment of post-CD19 CAR T-cell relapsed MCL patients in a first in-human phase 1b VLS-101 trial. The upcoming testing in a clinical setting will provide important insights on this new therapeutic development aiming to overcome the CAR T resistance via targeting ROR1, which is a rising unmet clinical need in MCL.

Longitudinal single-cell profiling reveals molecular heterogeneity and tumor-immune evolution in refractory mantle cell lymphoma

The mechanisms driving therapeutic resistance and poor outcomes of mantle cell lymphoma (MCL) are incompletely understood. We characterize the cellular and molecular heterogeneity within and across patients and delineate the dynamic evolution of tumor and immune cell compartments at single cell resolution in longitudinal specimens from ibrutinib-sensitive patients and non-responders. Temporal activation of multiple cancer hallmark pathways and acquisition of 17q are observed in a refractory MCL. Multi-platform validation is performed at genomic and cellular levels in PDX models and larger patient cohorts. We demonstrate that due to 17q gain, BIRC5/survivin expression is upregulated in resistant MCL tumor cells and targeting BIRC5 results in marked tumor inhibition in preclinical models. In addition, we discover notable differences in the tumor microenvironment including progressive dampening of CD8+ T cells and aberrant cell-to-cell communication networks in refractory MCLs. This study reveals diverse and dynamic tumor and immune programs underlying therapy resistance in MCL.

Evaluating assumptions of definition-based pulmonary exacerbation endpoints in cystic fibrosis clinical trials

BACKGROUND

Cystic fibrosis (CF) pulmonary exacerbations can be serious respiratory events and reduction in exacerbation rate or risk are important efficacy endpoints for CF therapeutic trials. Variability in exacerbation diagnoses and treatment have led drug developers to employ "objective" exacerbation definitions combining antimicrobial treatment (AT) and the presence of ≥4 of 12 respiratory criteria (first published by Fuchs et al. [NEJM 1994;331(10):637-42]). Assumptions underlying this approach have yet to be formally evaluated.

METHODS

Respiratory events (RE) observed during a 48-week trial of ataluren (NCT02139306), a read-through agent for premature nonsense codons, were compared across six exacerbation definitions: any AT, intravenous AT (IVAT), ≥4 Fuchs criteria present, AT plus ≥4 Fuchs criteria, IVAT plus ≥4 Fuchs criteria, and investigator assessment. Fuchs definitions were evaluated by assessing missingness of individual criteria and associations between criteria presence and clinician exacerbation assessment.

RESULTS

Among 751 RE, more than one third had ≥4 Fuchs criteria present but were not assessed as exacerbations by investigators. Data for ≥1 and for 4 Fuchs criteria, respectively, were missing for ~ 90% and >30% of RE. Only 6/12 Fuchs criteria were present more often when investigators assessed RE as exacerbations than when they did not.

CONCLUSIONS

"Objective" definitions have shortcomings inconsistent with their purpose of optimizing exacerbation capture in clinical trials : 1) they capture events clinicians do not consider exacerbations, 2) are prone to data missingness which can bias the likelihood of meeting the definition, and 3) employ criteria that are not associated with investigator assessment of exacerbation.

Meta-analyses of ataluren randomized controlled trials in nonsense mutation Duchenne muscular dystrophy

Aim: Assess the totality of efficacy evidence for ataluren in patients with nonsense mutation Duchenne muscular dystrophy (nmDMD). Materials & methods: Data from the two completed randomized controlled trials (ClinicalTrials.gov: NCT00592553; NCT01826487) of ataluren in nmDMD were combined to examine the intent-to-treat (ITT) populations and two patient subgroups (baseline 6-min walk distance [6MWD] ≥300–<400 or <400 m). Meta-analyses examined 6MWD change from baseline to week 48. Results: Statistically significant differences in 6MWD change with ataluren versus placebo were observed across all three meta-analyses. Least-squares mean difference (95% CI): ITT (n = 342), +17.2 (0.2–34.1) m, p = 0.0473; ≥300–<400 m (n = 143), +43.9 (18.2–69.6) m, p = 0.0008; <400 m (n = 216), +27.7 (6.4–49.0) m, p = 0.0109. Conclusion: These meta-analyses support previous evidence for ataluren in slowing disease progression versus placebo in patients with nmDMD over 48 weeks. Treatment benefit was most evident in patients with a baseline 6MWD ≥300–<400 m (the ambulatory transition phase), thereby informing future trial design.

Abstract 5683: Single-cell RNA-seq reveals heterogeneity, clonal evolution and strategies to overcome ibrutinib-venetoclax dual resistance in mantle cell lymphoma

Introduction The clinical, pathological, genetic, and transcriptomic characteristics of mantle cell lymphoma (MCL) are extremely heterogeneous, and MCL patients frequently develop therapeutic resistance after frontline therapies. In this study, we performed longitudinal transcriptomic analysis on patient specimens at the single-cell level, aiming to understand the dynamic and complex cellular and molecular changes underlying therapeutic resistance and to identify potential targets to overcome dual resistance to ibrutinib and venetoclax.

Methods Single-cell RNA-seq was performed on sequential MCL patient specimens. Integrative computational approaches were employed to characterize the cellular and molecular basis of therapeutic resistance and clonal evolution. Bulk RNA sequencing, deep WES, and 17-color flow analysis of multiple patient cohorts were used to validate the novel findings. An orthotopic PDX model derived from one of the ibrutinib-venetoclax non-responders was used for further analysis and to investigate the in vivo efficacy of therapeutic agents against multiple actionable targets.

Results To dissect the inter- and intra-tumor heterogeneity underlying the therapeutic resistance, we performed sequential scRNA-seq analysis of 21 specimens (18,794 cells in total) collected from 3 ibrutinib responders and 2 ibrutinib-venetoclax non-responders along the course of ibrutinib and/or venetoclax treatments. The analysis revealed a high degree of inter- and intra-tumor heterogeneity with distinct cellular and transcriptomic profiling within and across ibrutinib-responders and ibrutinib-venetoclax non-responders. The observed transcriptomic evolution of cancer hallmarks associated with disease progression and therapeutic resistance were faithfully passed onto the orthotopic PDX model derived from one of the ibrutinib-venetoclax non-responders. We tracked the clinical ibrutinib-induced lymphocytosis at a single-cell level in ibrutinib responders and disease progression-associated clonal evolution in non-responders, which was validated by deep WES analysis. 17q gain in non-responders was further validated in a larger patient cohort. Our analysis revealed the reprogramming of tumor microenvironment and tumor immune evasion, which was further validated by 17-color flow analysis in a large cohort (n = 70). Inhibition of multiple actionable targets showed effective anti-MCL activity in the PDX model to overcome the ibrutinib-venetoclax dual resistance.

Conclusions This study demonstrates the potential of longitudinal single-cell transcriptomic analysis to reveal the molecular mechanisms underlying tumor heterogeneity, clonal evolution, disease progression, and therapeutic resistance, and to identify potential novel targets to circumvent therapeutic resistance in MCL and other diseases.

Citation Format: Changying Jiang, Shaojun Zhang, Yuanxin Wang, Rongjia Zhang, Yang Liu, Joseph McIntosh, Guangchun Han, Ruiping Wang, David Santos, Maria Badillo, Angela Leeming, Zhihong Chen, Kimberly Hartig, John Bigcal, Hun Lee, Raphael Steiner, Jorge Romaguera, Preetesh Jain, Krystle Nomie, Andy Futreal, Linghua Wang, Michael Wang. Single-cell RNA-seq reveals heterogeneity, clonal evolution and strategies to overcome ibrutinib-venetoclax dual resistance in mantle cell lymphoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5683.

Efficacy and safety of ataluren in patients with nonsense-mutation cystic fibrosis not receiving chronic inhaled aminoglycosides: The international, randomized, double-blind, placebo-controlled Ataluren Confirmatory Trial in Cystic Fibrosis (ACT CF)

BACKGROUND

Ataluren was developed for potential treatment of nonsense-mutation cystic fibrosis (CF). A previous phase 3 ataluren study failed to meet its primary efficacy endpoint, but post-hoc analyses suggested that aminoglycosides may have interfered with ataluren's action. Thus, this subsequent trial (NCT02139306) was designed to assess the efficacy and safety of ataluren in patients with nonsense-mutation CF not receiving aminoglycosides.

METHODS

Eligible subjects with nonsense-mutation CF (aged ≥6 years; percent predicted (pp) FEV1 ≥40 and ≤90) from 75 sites in 16 countries were randomly assigned in double-blinded fashion to receive oral ataluren or matching placebo thrice daily for 48 weeks. The primary endpoint was absolute change in average ppFEV1 from baseline to the average of Weeks 40 and 48.

FINDINGS

279 subjects were enrolled; 138 subjects in the ataluren arm and 136 in the placebo arm were evaluable for efficacy. Absolute ppFEV1 change from baseline did not differ significantly between the ataluren and placebo groups at Week 40 (-0.8 vs -1.8) or Week 48 (-1.7 vs -2.4). Average ppFEV1 treatment difference from baseline to Weeks 40 and 48 was 0.6 (95% CI -1.3, 2.5; p = 0.54). Pulmonary exacerbation rate per 48 weeks was not significantly different (ataluren 0.95 vs placebo 1.13; rate ratio p = 0.40). Safety was similar between groups. No life-threatening adverse events or deaths were reported.

INTERPRETATION

Neither ppFEV1 change nor pulmonary exacerbation rate over 48 weeks were statistically different between ataluren and placebo groups. Development of a nonsense-mutation CF therapy remains elusive.

Ataluren Pharmacokinetics in Healthy Japanese and Caucasian Subjects

To evaluate the potential for ethnicity-related differences in ataluren pharmacokinetics (PK) and safety, a phase 1 single-dose study was conducted in 48 healthy (24 Japanese and 24 Caucasian subjects), nonsmoking male volunteers who were equally divided into 3 cohorts of oral doses at 5, 10, and 20 mg/kg. Blood samples were collected until 48 hours postdose. PK results demonstrated rapid absorption of ataluren, with peak plasma levels (C_max ) being attained between 0.875 and 2.5 hours after dosing. The mean C_max and area under the concentration-time curve (AUC_(0-last) ) increased with each increasing dose level in both Japanese and Caucasian subjects. Although the C_max was similar across all subjects at each dose regardless of ethnicity, Japanese subjects had a mean AUC_(0-last) approximately 14% to 34% lower than that of Caucasian subjects across the 3 dose levels. This difference was likely due to the higher variability of AUC values in Caucasian subjects and the relatively small study population. In conclusion, similar ataluren PK profiles were observed in healthy Japanese and Caucasian subjects following single oral administration of ataluren at all dose levels.

The relationship between deficit in digit span and genotype in nonsense mutation Duchenne muscular dystrophy

OBJECTIVE

To evaluate the relationship between deficit in digit span and genotype in nonsense mutation (nm) Duchenne muscular dystrophy (DMD) (nmDMD).

METHODS

We investigated the relationship between normalized digit-span forward (d-sf) and digit-span backward (d-sb) scores to the location of nmDMD mutations in 169 participants ≥5 to ≤20 years who participated in a phase 2b clinical trial. Because alternative promoters are found upstream of DMD exons 30, 45, and 63, we correlated d-sf and d-sb to the specific nmDMD mutation location.

RESULTS

Participants with nm downstream of exon 30, downstream of exon 45, and downstream of exon 63 had significantly lower normalized d-sf scores (p < 0.0001). Participants with nm downstream of exon 45 in addition had significantly lower normalized d-sb score (p < 0.04). There was no significant difference in the normalized d-sb score in participants with mutations upstream or downstream of DMD exon 30 or upstream or downstream of DMD exon 63.

CONCLUSION

Our data provide evidence that specific cognitive deficits correlate to genotype in individuals with nmDMD, highlighting the critical role of brain-specific dystrophin isoforms in the neurobiological manifestations of this disease.

CLINICALTRIALSGOV IDENTIFIER

NCT02090959.

Ataluren in patients with nonsense mutation Duchenne muscular dystrophy (ACT DMD): a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

Duchenne muscular dystrophy (DMD) is a severe, progressive, and rare neuromuscular, X-linked recessive disease. Dystrophin deficiency is the underlying cause of disease; therefore, mutation-specific therapies aimed at restoring dystrophin protein production are being explored. We aimed to assess the efficacy and safety of ataluren in ambulatory boys with nonsense mutation DMD.

METHODS

We did this multicentre, randomised, double-blind, placebo-controlled, phase 3 trial at 54 sites in 18 countries located in North America, Europe, the Asia-Pacific region, and Latin America. Boys aged 7-16 years with nonsense mutation DMD and a baseline 6-minute walk distance (6MWD) of 150 m or more and 80% or less of the predicted normal value for age and height were randomly assigned (1:1), via permuted block randomisation (block size of four) using an interactive voice-response or web-response system, to receive ataluren orally three times daily (40 mg/kg per day) or matching placebo. Randomisation was stratified by age (<9 years vs ≥9 years), duration of previous corticosteroid use (6 months to <12 months vs ≥12 months), and baseline 6MWD (<350 m vs ≥350 m). Patients, parents and caregivers, investigational site personnel, PTC Therapeutics employees, and all other study personnel were masked to group allocation until after database lock. The primary endpoint was change in 6MWD from baseline to week 48. We additionally did a prespecified subgroup analysis of the primary endpoint, based on baseline 6MWD, which is reflective of anticipated rates of disease progression over 1 year. The primary analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT01826487.

FINDINGS

Between March 26, 2013, and Aug 26, 2014, we randomly assigned 230 patients to receive ataluren (n=115) or placebo (n=115); 228 patients comprised the intention-to-treat population. The least-squares mean change in 6MWD from baseline to week 48 was -47·7 m (SE 9·3) for ataluren-treated patients and -60·7 m (9·3) for placebo-treated patients (difference 13·0 m [SE 10·4], 95% CI -7·4 to 33·4; p=0·213). The least-squares mean change for ataluren versus placebo in the prespecified subgroups was -7·7 m (SE 24·1, 95% CI -54·9 to 39·5; p=0·749) in the group with a 6MWD of less than 300 m, 42·9 m (15·9, 11·8-74·0; p=0·007) in the group with a 6MWD of 300 m or more to less than 400 m, and -9·5 m (17·2, -43·2 to 24·2; p=0·580) in the group with a 6MWD of 400 m or more. Ataluren was generally well tolerated and most treatment-emergent adverse events were mild to moderate in severity. Eight (3%) patients (n=4 per group) reported serious adverse events; all except one event in the placebo group (abnormal hepatic function deemed possibly related to treatment) were deemed unrelated to treatment.

INTERPRETATION

Change in 6MWD did not differ significantly between patients in the ataluren group and those in the placebo group, neither in the intention-to-treat population nor in the prespecified subgroups with a baseline 6MWD of less than 300 m or 400 m or more. However, we recorded a significant effect of ataluren in the prespecified subgroup of patients with a baseline 6MWD of 300 m or more to less than 400 m. Baseline 6MWD values within this range were associated with a more predictable rate of decline over 1 year; this finding has implications for the design of future DMD trials with the 6-minute walk test as the endpoint.

FUNDING

PTC Therapeutics.

An improved human anxiety process biomarker: characterization of frequency band, personality and pharmacology

Anxiety disorders are among the most common mental illness in the western world with a major impact on disability. But their diagnosis has lacked objective biomarkers. We previously demonstrated a human anxiety process biomarker, goal-conflict-specific electroencephalography (EEG) rhythmicity (GCSR) in the stop-signal task (SST). Here we have developed and characterized an improved test appropriate for clinical group testing. We modified the SST to produce balanced numbers of trials in clearly separated stop-signal delay groups. As previously, right frontal (F8) GCSR was extracted as the difference in EEG log Fourier power between matching stop and go trials (that is, stop-signal-specific power) of a quadratic contrast of the three delay values (that is, power when stopping and going are in balanced conflict compared with the average of when stopping or going is greater). Separate experiments assessed drug sensitivity (n=34) and personality relations (n=59). GCSR in this new SST was reduced by three chemically distinct anxiolytic drugs (administered double-blind): buspirone (10 mg), triazolam (0.25 mg) and pregabalin (75 mg); had a frequency range (4-12 Hz) consistent with rodent model data; and positively correlated significantly with neuroticism and nonsignificantly with trait anxiety scores. GCSR, measured in our new form of the SST, should be suitable as a biomarker for one specific anxiety process in the testing of clinical groups and novel drugs and in the development of measures suitable for individual diagnosis.

Long term developmental outcomes of pre-school age children following laser surgery for twin-to-twin transfusion syndrome

BACKGROUND

Laser therapy is now a well recognised treatment for twin-to-twin transfusion syndrome (TTTS). We investigated the early childhood neurodevelopmental outcome of children post laser treatment for TTTS in our centre.

METHODS

Children of women who had laser therapy for TTTS between March 2006 and June 2008 were assessed at 30-69 months of age with WPPSI-III and a general health questionnaire. Major neurodevelopmental impairment (NDI) was reported as IQ<70 or cerebral palsy (CP). Borderline cognitive impairment was defined by IQ 70-79.

RESULTS

Amongst the 37 pregnancies treated, 62 infants were discharged home and the overall foetal survival rate was 84%. A total of 50 children (84%) from 31 pregnancies were assessed. Average age at assessment was 47 months. Two children with late treatment of congenital hypothyroidism were excluded. The majority of pregnancies were Quintero Stage III (74%). There was a significant trend for worse outcome with higher Quintero stage. The average gestational age at birth was 32 weeks. The majority (39, 78%) of children were found to be neurodevelopmentally normal; 9 (18%) had borderline cognitive development; and 2 (4%) had a major NDI, including one with cerebral palsy (2%).

CONCLUSIONS

There was a modest level of neurocognitive impairment post laser therapy for TTTS, mainly borderline cognitive development, lesser so major NDI. There was a low incidence of cerebral palsy. Routine developmental and neurological follow-up of these children is recommended.

Homogeneity, Anisotropy, and Texture In Si3n4 Ceramics made by Fused Deposition

The Fused Deposition of Ceramics (FDC) process is an extrusion based layered manufacturing technique. In this study, the microstructural and property homogeneity of GS44-Si3N4 parts made by FDC is examined. The feedstock, green, and sintered parts were examined using characterization techniques such as optical and scanning electron microscopy, x-ray radiography, and x-ray diffraction. In addition, mechanical properties (σf, and Klc), shrinkage, and warpage results were used to characterize the FDC parts. It was found that by using proper build parameters and tool paths, dense, homogenous, near-net-shape GS44-Si3N4 parts can be fabricated. While the mechanical properties of these parts are shown to be isotropic, there is some degree of texturing detected with XRD. Si3N4 filament feedstock intentionally textured with 5.5 vol% of β-seed particles has also been made.

AAV-mediated knockdown of peripherin-2 in vivo using miRNA-based hairpins

Gene therapy for inherited retinal degeneration in which expression of a mutant allele has a gain-of-function effect on photoreceptor cells is likely to depend on efficient silencing of the mutated allele. Peripherin-2 (Prph2, also known as peripherin/RDS) is an abundantly expressed photoreceptor-specific gene. In humans, gain-of-function mutations in PRPH2 result in both autosomal dominant retinitis pigmentosa and dominant maculopathies. Gene-silencing strategies for these conditions include RNA interference by short hairpin RNAs (shRNAs). Recent evidence suggests that microRNA (miRNA)-based hairpins may offer a safer and more effective alternative. In this study, we used for the first time a virally transferred miRNA-based hairpin to silence Prph2 in the murine retina. The results show that an miRNA-based shRNA can efficiently and specifically silence Prph2 in vivo as early as 3 weeks after AAV2/8-mediated subretinal delivery, leading to a nearly 50% reduction of photoreceptor cells after 5 weeks. We conclude that miRNA-based hairpins can achieve rapid and robust gene silencing after efficient vector-mediated delivery to the retina. The rationale of using an miRNA-based template to improve the silencing efficiency of a hairpin may prove valuable for allele-specific silencing in which the choice for an RNAi target is limited and offers an alternative therapeutic strategy for the treatment of dominant retinopathies.

Effect of a staffing strategy based on voluntary increase in working hours on quality of patient care in a hospital in KwaZulu-Natal

Two of the issues facing the South African Health Care System are the shortage of nursing staff and a lack of adequate skills to provide quality patient care. The hospital under study experienced a critical shortage of applications from professional registered nurses, consequently a staffing strategy was implemented to overcome the shortage of nurses and to maintain quality patient care. The strategy introduced encouraged nurses to voluntarily work an additional ten hours per week with remuneration. A non-experimental, descriptive design with a quantitative approach was applied to investigate the effect of a staffing strategy aimed at improving the quality of care in a hospital in Kwa-Zulu Natal based on voluntarily increasing staff working hours. The investigation compared the quality of nursing care before and after the implementation of the staffing strategy through retrospective audits of randomly selected patient files 372 (11%) of the total population of 400 files were audited. A random sample of 4 boxes each containing a 100 patient files, of a total of 34 boxes, was selected from the hospital filing system. Descriptive statistical analyses were performed and correlations between various variables using the Chi-square test. No statistically significant differences (p<0.05) were found between the quality of nursing care before and after the implementation of the management strategy, even though deterioration of results after the implementation was observed. The study shows that the quality of nursing care in most wards deteriorated after implementation. The staffing strategy failed to improve or maintain the quality of nursing care.