The changing epidemiology of pulmonary infection in children and adolescents with cystic fibrosis: an 18-year experience

The impact of evolving treatment regimens, airway clearance strategies, and antibiotic combinations on the incidence and prevalence of respiratory infection in cystic fibrosis (CF) in children and adolescents remains unclear. The incidence, prevalence, and prescription trends from 2002 to 2019 with 18,339 airway samples were analysed. Staphylococcus aureus [- 3.86% (95% CI - 5.28-2.43)] showed the largest annual decline in incidence, followed by Haemophilus influenzae [- 3.46% (95% CI - 4.95-1.96)] and Pseudomonas aeruginosa [- 2.80%95% CI (- 4.26-1.34)]. Non-tuberculous mycobacteria and Burkholderia cepacia showed a non-significant increase in incidence. A similar pattern of change in prevalence was observed. No change in trend was observed in infants < 2 years of age. The mean age of the first isolation of S. aureus (p < 0.001), P. aeruginosa (p < 0.001), H. influenza (p < 0.001), Serratia marcescens (p = 0.006) and Aspergillus fumigatus (p = 0.02) have increased. Nebulised amikacin (+ 3.09 ± 2.24 prescription/year, p = 0.003) and colistin (+ 1.95 ± 0.3 prescriptions/year, p = 0.032) were increasingly prescribed, while tobramycin (- 8.46 ± 4.7 prescriptions/year, p < 0.001) showed a decrease in prescription. Dornase alfa and hypertonic saline nebulisation prescription increased by 16.74 ± 4.1 prescriptions/year and 24 ± 4.6 prescriptions/year (p < 0.001). There is a shift in CF among respiratory pathogens and prescriptions which reflects the evolution of cystic fibrosis treatment strategies over time.

Factors influencing treatment response of pulmonary exacerbation in children with cystic fibrosis

BACKGROUND

Pulmonary exacerbations in cystic fibrosis (CF) significantly impact morbidity and mortality. This study aimed to assess treatment response rates and identify contributing factors towards treatment response.

METHODS

In this single-center, retrospective, longitudinal study spanning four years, we analyzed all pulmonary exacerbation admissions. We compared lung function at baseline, admission, end of treatment, and 6-week follow-up. Treatment response was defined as ≥95% recovery of baseline FEV1%.

RESULTS

There were 78 children who required a total of 184 admissions. The mean duration of treatment was 14.9±2.9 days. FEV1% returned to 95% of baseline in 59% following treatment. The magnitude of the decline in lung function on admission in children who did not respond to treatment was 21.7±15.2% while the decline in children who responded to treatment was 8.3±9.4%, P<0.001. Children who experienced a decline in FEV1% greater than 40% exhibited an 80% reduced likelihood of returning to their baseline values (OR -0.8, 95% CI -0.988; -0.612). Similarly, those with FEV1% reductions in the ranges of 30-39% (OR -0.63, 95% CI -0.821; -0.439), 20-29% (OR -0.52, 95% CI -0.657; -0.383), and 10-19% (OR -0.239, 95% CI -0.33; -0.148) showed progressively lower odds of returning to baseline. Fourty-eight children required readmission within 7.7±5.4 months, children who responded to treatment had a longer time taken to readmission (8.9±6.4 months) versus children who did not respond to treatment (6.4±3.5 months), (OR: -0.20, 95% CI -0.355; -0.048).

CONCLUSIONS

A greater decline in lung function on admission and readmission within 6 months of the initial admission predicts non-response to treatment. This highlights the importance of re-evaluating follow-up strategies following discharge.

Can postural changes in spirometry in children with Duchenne muscular dystrophy predict sleep hypoventilation?

AIM

To explore the relationship between postural changes in lung function and polysomnography (PSG) in children with Duchenne muscular dystrophy (DMD).

METHODS

In this prospective cross-sectional study, children with DMD performed spirometry in sitting and supine positions. A control group of age and gender matched healthy children also underwent postural lung function testing. PSG was performed within six months of spirometry.

RESULTS

Seventeen children with DMD, aged 12.3 ± 3 years performed sitting spirometry. 14 (84%) performed acceptable spirometry in the supine position. Mean FEV1sit and FVCsit were 77% (SD ± 22) and 74% (SD ± 20.4) respectively, with mean% ΔFVC(sit-sup) 9% (SD ± 11) (range 2% to 20%), and was significantly greater than healthy controls 4% (n = 30, SD ± 3, P < 0.001). PSG data on the 14 DMD children with acceptable supine spirometry showed total AHI 6.9 ± 5.9/hour (0.3 to 29), obstructive AHI 5.2 ± 4.0/hour (0.2 to 10), and REM AHI 14.1 ± -5.3/hour (0.1 to 34.7). ΔFVC(sit-sup) had poor correlation with hypoventilation on polysomnography.

CONCLUSION

Children with DMD and mild restrictive lung disease showed greater postural changes in spirometry than healthy controls but lower supine spirometry was not predictive of sleep hypoventilation.

Recent advances and challenges in the utilization of nanomaterials in transesterification for biodiesel production

Due to diminishing fossil fuel supplies and rising energy needs, there has been an ever-increasing demand for renewable energy sources. The available renewable energy resources, such as solar, wind, hydropower, and biofuels, provide a new way of supplying the world's energy needs. Biofuels stand out among them because they are sustainable and have the potential to bring the idea of a global bioeconomy to life. As a result of their production of biofuels like biomethane, biohydrogen, and biodiesel, atmospheric CO₂ is being fixed, eventually lowering the world's carbon footprint. Current developments in the production of bioenergy have concentrated on producing biodiesel among other biofuels. Biodiesel is being produced from a variety of feedstocks using a number of processes, including transesterification, micro-emulsion, direct mixing, and pyrolysis. The most popular method among these is transesterification, which makes use of a variety of catalysts. As a result of the development of nanotechnology, nanocatalysts with desirable properties, such as increased catalytic activity, increased surface area, and superior thermal stability, have been made and modified. In this review, various nanocatalyst types and manufacturing processes are examined in relation to transesterification. It explores how crucial nanocatalysts are in boosting biodiesel production, highlights potential barriers, and makes recommendations for their widespread use in the future.

Approaches to the management of haemoptysis in young people with cystic fibrosis

Haemoptysis occurs in up to 25 % of young people with Cystic fibrosis (CF) [1]. We undertook a literature review and described the management approach to haemoptysis in CF between 2010 and 2020 at an Australian tertiary paediatric centre, The Children's Hospital Westmead, Sydney, New South Wales, using a retrospective review of the medical records which identified 67 episodes. Sixty episodes met inclusion criteria, including 31 patients. Using the US CF Foundation guidelines, episodes were classified as scant (53.3 %), moderate (38.3 %) or massive (8.3 %). Fifty-two percent of patients were female, mean age at presentation was 15.4 years (SD+/- 2.4) and 58 % were homozygous for the Fdel508 genotype. Twelve episodes (9 patients) required bronchial artery embolization (BAE). BAE was used in all cases of massive haemoptysis 5/5 (100 %), 6/23 (22 %) episodes of moderate and 1/32 (3 %) episode of scant haemoptysis as an elective procedure for recurrent haemoptysis. Our literature review and institutional experience highlights the need for up-to-date management guidelines in the management of haemoptysis in Cystic Fibrosis. Based on our experience, we provide a proposed algorithm to help guide the management of haemoptysis in CF.

Integrating Human Waste with Microbial Fuel Cells to Elevate the Production of Bioelectricity

Due to the continuous depletion of natural resources currently used for electricity generation, it is imperative to develop alternative energy sources. Human waste is nowadays being explored as an efficient source to produce bio-energy. Human waste is renewable and can be used as a source for an uninterrupted energy supply in bioelectricity or biofuel. Annually, human waste such as urine is produced in trillions of liters globally. Hence, utilizing the waste to produce bioenergy is bio-economically suitable and ecologically balanced. Microbial fuel cells (MFCs) play a crucial role in providing an effective mode of bioelectricity production by implementing the role of transducers. MFCs convert organic matter into energy using bio-electro-oxidation of material to produce electricity. Over the years, MFCs have been explored prominently in various fields to find a backup for providing bioenergy and biofuel. MFCs involve the role of exoelectrogens which work as transducers to convert the material into electricity by catalyzing redox reactions. This review paper demonstrates how human waste is useful for producing electricity and how this innovation would be beneficial in the long term, considering the current scenario of increasing demand for the supply of products and shortages of natural resources used to produce biofuel and bioelectricity.

Use of biomass-derived biochar in wastewater treatment and power production: A promising solution for a sustainable environment

Over the past few years, we are witnessing the advent of a revolutionary bioengineering technology in biochar production and its application in waste treatment and an important component in power generation devices. Biochar is a solid product, highly rich in carbon, whose adsorption properties are ideal for wastewater decontamination. Due to its high specific surface area to volume ratio, it can be utilized for many environmental applications. It has diverse applications in various fields. This review focuses on its various applications in wastewater treatment to remove various pollutants such as heavy metals, dyes, organic compounds, and pesticides. This review also highlights several energy-based applications in batteries, supercapacitors, and microbial fuel cells. It described information about the different feedstock materials to produce LB-derived biochar, the various conditions for the production process, i.e., pyrolysis and the modification methods of biochar for improving properties required for wastewater treatment. The present review helps the readers understand the importance of biochar in wastewater treatment and its application in power generation in terms of batteries, supercapacitors, microbial fuel cells, applications in fuel production, pollutant and dye removal, particularly the latest development on using LB-derived biochar. This review also highlights the economic and environmental sustainability along with the commercialization of biochar plants. It also describes various pyrolytic reactors utilized for biochar production.

Transition to adult care in cystic fibrosis: The challenges and the structure

In developed countries, it is projected that there will be a 70% increase in the number of adults living with Cystic Fibrosis (CF) between 2010 and 2025. This shift in demographics highlights the importance of high-quality transition programmes with developmentally appropriate integrated health care services as the individual moves through adolescence to adulthood. Adolescents living with CF face additional and unique challenges that may have long-term impacts on their health, quality of life and life-expectancy. CF specific issues around socially challenging symptoms, body image, reproductive health and treatment burden differentiate people with CF from their peers and require clinicians to identify and address these issues during the transition process. This review provides an overview of the health, developmental and psychosocial challenges faced by individuals with CF, their guardians and health care teams considering the fundamental components and tools that are required to build a transition programme that can be tailored to suit individual CF clinics.

Update in management of paediatric primary spontaneous pneumothorax

Paediatric spontaneous pneumothorax (PSP) management continues to lack paediatric-specific guideline recommendations. There have been increasing reports of paediatric retrospective case studies supplemented by important well designed RCT (predominantly) adult studies. Taken together, these suggest that conservative management may have an increasing role to play in the management of PSP and that aspiration may have limited utility as a first line intervention. Our local experience, as part of a multicentre retrospective analysis and subsequent audit of management since, corroborates recent published data: it highlights an increasing trend towards conservative management in spontaneous pneumothorax with similar rates of recurrence, compared to intervention, and low use of aspiration with similarly low success rates. We have therefore updated our local practice guidelines and share these with readers. Specifically, we have removed aspiration in the management of primary spontaneous pneumothorax and reserved intervention for children who are clinically unstable or show evidence of increasing air leak irrespective of pneumothorax size. Whilst the success of this change in clinical practice will need to be reviewed in the next 5-10 years, the overall low incidence of the condition, demands a multicentre, and probably multinational, collaborative approach to allow the best chance of obtaining definitive evidence to guide clinical paediatric management.

Discovery of MAP855, an Efficacious and Selective MEK1/2 Inhibitor with an ATP-Competitive Mode of Action

Mutations in MEK1/2 have been described as a resistance mechanism to BRAF/MEK inhibitor treatment. We report the discovery of a novel ATP-competitive MEK1/2 inhibitor with efficacy in wildtype (WT) and mutant MEK12 models. Starting from a HTS hit, we obtained selective, cellularly active compounds that showed equipotent inhibition of WT MEK1/2 and a panel of MEK1/2 mutant cell lines. Using a structure-based approach, the optimization addressed the liabilities by systematic analysis of molecular matched pairs (MMPs) and ligand conformation. Addition of only three heavy atoms to early tool compound 6 removed Cyp3A4 liabilities and increased the cellular potency by 100-fold, while reducing log P by 5 units. Profiling of MAP855, compound 30, in pharmacokinetic-pharmacodynamic and efficacy studies in BRAF-mutant models showed comparable efficacy to clinical MEK1/2 inhibitors. Compound 30 is a novel highly potent and selective MEK1/2 kinase inhibitor with equipotent inhibition of WT and mutant MEK1/2, whose drug-like properties allow further investigation in the mutant MEK setting upon BRAF/MEK therapy.

Paediatric empyema: worsening disease severity and challenges identifying patients at increased risk of repeat intervention

OBJECTIVE

Empyema is the most common complication of pneumonia. Primary interventions include chest drainage and fibrinolytic therapy (CDF) or video-assisted thoracoscopic surgery (VATS). We describe disease trends, clinical outcomes and factors associated with reintervention.

DESIGN/SETTING/PATIENTS

Retrospective cohort of paediatric empyema cases requiring drainage or surgical intervention, 2011-2018, admitted to a large Australian tertiary children's hospital.

RESULTS

During the study, the incidence of empyema increased from 1.7/1000 to 7.1/1000 admissions (p<0.001). We describe 192 cases (174 CDF and 18 VATS), median age 3.0 years (IQR 1-5), mean fever duration prior to intervention 6.2 days (SD ±3.3 days) and 50 (26%) cases admitted to PICU. PICU admission increased during the study from 18% to 34% (p<0.001). Bacteraemia occurred in 23/192 (12%) cases. A pathogen was detected in 131/192 (68%); Streptococcus pneumoniae 75/192 (39%), S. aureus 25/192 (13%) and group A streptococcus 13/192 (7%). Reintervention occurred in 49/174 (28%) and 1/18 (6%) following primary CDF and VATS. Comparing repeat intervention with single intervention cases, a continued fever postintervention increased the likelihood for a repeat intervention (OR 1.3 per day febrile; 95% CI 1.2 to 1.4, p<0.0001). Younger age, prolonged fever preintervention and previous antibiotic treatment were not associated with initial treatment failure (all p>0.05).

CONCLUSION

We report increasing incidence and severity of empyema in a large tertiary hospital. One in four patients required a repeat intervention after CDF. Neither clinical variables at presentation nor early investigations were able to predict initial treatment failure.

Use of non-invasive ventilation in children with congenital tracheal stenosis

INTRODUCTION

Congenital tracheal stenosis (CTS) is a rare airway condition characterized by complete tracheal rings. Most patients undergo a slide tracheoplasty, which greatly reduces mortality but significant morbidity remains. The assessment of sleep disordered breathing (SDB) and use of non-invasive ventilation (NIV) in these children has not been described.

AIM

To describe the presence of SDB and use of NIV in children diagnosed with CTS over a 10-year period (2005-2015).

DESIGN

Retrospective case series at a tertiary children's hospital.

RESULTS

There were 16 patients identified with CTS with a median [range] age at diagnosis of 2.5 months (0-9 months). One child died in the immediate post-operative period following a slide tracheoplasty, leaving 15 survivors. There were no later deaths during follow-up while using NIV for up to 3 years after surgery. Slide tracheoplasty was undertaken in (12/15) with long-segment tracheal stenosis. 3/15 patients had a short-segment tracheal stenosis and were managed conservatively. The use of NIV occurred in 10/15 (66.67%) patients, all of whom had long-segment CTS. Pre-operative polysomnography (PSG) showed a median (±SD) obstructive apnoea/hypopnoea index (OAHI) of 14.6/hr (±6.2) which reduced to 7.2/hour (±4.2) on NIV prior to slide tracheoplasty. The median oxygen desaturation index (ODI) before NIV use was 15.3 (±19.4) episodes/hour, which reduced to 6.3 (±11) on NIV. The median period of NIV use was 5 [1-24 months] months.

CONCLUSION

Patients with CTS have obstructed sleep disordered breathing. Trials of NIV are well-tolerated and improve sleep disordered breathing.

Increasing Rates of Pediatric Empyema and Disease Severity With Predominance of Serotype 3 S. pneumonia: An Australian Single-center, Retrospective Cohort 2011 to 2018

BACKGROUND

The impact of universal 13-valent pneumococcal conjugate vaccine immunization on pediatric empyema rates and pathogens in Australia is not known. We aimed to describe empyema epidemiology, clinical characteristics and treatment during an 8-year period.

METHODS

A retrospective study between 2011 and 2018 of empyema cases admitted to a large pediatric referral hospital, for management with either pleural drainage and fibrinolytics or surgical intervention.

RESULTS

There were 195 cases in 8 years. Empyema incidence and ICU admission rates significantly increased during the study with a peak incidence of 7.1/1000 medical admissions in 2016 (χ for trend of incidence 37.8, P < 0.001 and for ICU admissions 15.3, P < 0.001). S. pneumoniae was the most common pathogen (75/195, 39%) with serotype 3 the most detected (27/75: 27%). S. pyogenes compared with S. pneumoniae had significantly fewer days of fever before admission (3.9 vs. 6.4, mean difference 2.4, 95% CI: 0.84-4.08, P = 0.003) and higher proportion requiring direct ICU admission (6/75; 8% vs. 7/15; 47%, P < 0.001). Compared with S. pneumoniae, cases with no pathogen detected by culture or PCR had fewer days of fever post intervention (4.4 vs. 7.4 days, mean difference 2.7 days, P = 0.002). S. aureus occurred more commonly in infants (10/25; 40% vs. 1/75; 1%, P < 0.001) and children of indigenous background (5/25; 20% vs. 1/75; 1%, P < 0.001) compared with S. pneumoniae.

CONCLUSIONS

We report increasing rates of pediatric empyema with higher proportions requiring ICU treatment. The most common pathogens detected were S. pneumoniae, S. aureus and S. pyogenes. Despite high 13-valent pneumococcal conjugate vaccine coverage, serotype 3 was the most common S. pneumoniae serotype identified.

Glibenclamide treatment in a Cantú syndrome patient with a pathogenic ABCC9 gain-of-function variant: Initial experience

Cantú syndrome (CS), characterized by hypertrichosis, distinctive facial features, and complex cardiovascular abnormalities, is caused by pathogenic variants in ABCC9 and KCNJ8 genes. These genes encode gain‐of‐function mutations in the regulatory (SUR2) and pore‐forming (Kir6.1) subunits of K_ATP channels, respectively, suggesting that channel‐blocking sulfonylureas could be a viable therapy. Here we report a neonate with CS, carrying a heterozygous ABCC9 variant (c.3347G>A, p.Arg1116His), born prematurely at 32 weeks gestation. Initial echocardiogram revealed a large patent ductus arteriosus (PDA), and high pulmonary pressures with enlarged right ventricle. He initially received surfactant and continuous positive airway pressure ventilation and was invasively ventilated for 4 weeks, until PDA ligation. After surgery, he still had ongoing bilevel positive airway pressure (BiPAP) requirement, but was subsequently weaned to nocturnal BiPAP. He was treated for pulmonary hypertension with Sildenafil, but failed to make further clinical improvement. A therapeutic glibenclamide trial was commenced in week 11 (initial dose of 0.05 mg^–1 kg^–1 day^–1 in two divided doses). After 1 week of treatment, he began to tolerate time off BiPAP when awake, and edema improved. Glibenclamide was well tolerated, and the dose was slowly increased to 0.15 mg⁻¹ kg⁻¹day⁻¹ over the next 12 weeks. Mild transient hypoglycemia was observed, but there was no cardiovascular dysfunction. Confirmation of therapeutic benefit will require studies of more CS patients but, based on this limited experience, consideration should be given to glibenclamide as CS therapy, although problems associated with prematurity, and complications of hypoglycemia, might limit outcome in critically ill neonates with CS.

Disease caused by non-tuberculous mycobacteria in children with cystic fibrosis

Non-tuberculous mycobacterial (NTM) (especially M. abscessus complex) infections pose a considerable challenge in the management of lung disease in patients with cystic fibrosis (CF). The apparent increase in prevalence is likely multifactorial. Emergent evidence of patient-to-patient transmission and isolation of highly resistant strains is a concern for all CF centers around the world. Treatment is often long and burdensome with multiple agents. Treatment side effects are frequent and can cause significant morbidity. Although consensus guidelines provide some direction, many units are faced with the challenges of: finding drug combinations for highly resistant strains; dealing with interruptions of treatment; discussing additional facilitating procedures in the form of gastrostomy and long-term vascular access devices; as well as supporting families emotionally and psychologically through the process.

Surgery in nontuberculous mycobacteria pulmonary disease

Medical treatment of pulmonary nontuberculous mycobacteria (NTM) disease has highly variable outcomes. Despite the use of multiple antibiotics, sputum clearance is often difficult to achieve, especially in cases with macrolide resistant NTM infection. Immunocompromised patients and those with structural lung disease are at increased risk, although occurrence in immunocompetent patients without structural lung disease is well recognised. Most pulmonary NTM disease involves Mycobacterium avium complex (MAC), but with enhanced identification multiple species have now been recognised as opportunistic pathogens. The observed increase in NTM disease, especially infection with multidrug-resistant Mycobacterium abscessus complex, is probably multifactorial. Surgery has been used as adjuvant treatment in patients with 1) focal disease that can be removed or 2) bothersome symptoms despite medical treatment that can be ameliorated. Early post-surgical mortality is low, but long-term morbidity and mortality are highly dependent on the degree of lung involvement and the residual lung function, the potency of medical treatment and the type of surgical intervention. In conjunction with antibiotic therapy, reported post-surgical sputum clearance was excellent, although publication bias should be considered. Bronchopleural fistulae were problematic, especially in pneumonectomy cases. Study results support the use of minimal resection surgery, in a carefully selected subgroup of patients with focal disease or persistent symptoms.

Educational aims

To critically review the literature describing the use of surgery in the treatment of pulmonary disease caused by nontuberculous mycobacteria (NTM).To assess the outcomes and complications observed with different surgical approaches used in the treatment of pulmonary NTM disease.

Abstract 1392: Preclinical In vivo evaluation of efficacy, pharmacokinetics and pharmacodynamics of novel PRMT5 inhibitors in multiple tumor models

PRMT5 is a typical type II methyltransferase, transferring two methyl groups to arginine, leading to symmetric dimethylation of the substrate. It can symmetrically methylate histones H2AR3, H3R2, H3R8, and H4R3 and can also methylate many non-histone proteins contributing to tumorigenesis by regulating cell cycle progression, DNA repair, cell growth, apoptosis, and inflammation. Overexpression of PRMT5 is reported in several human malignancies including lymphoma, glioma, melanoma, lung, breast, ovarian, and prostate cancers. Elevated levels correlate with poor prognosis in NSCLC, ovarian cancers, and GBM. Therefore, PRMT5 is considered an attractive target for cancer therapy. We sought to discover and develop PRMT5 inhibitors with the “best-in-class” profile with an emphasis on improved permeability for their potential use in solid tumors. Utilizing structure-guided drug design and SAR-based approaches, we have optimized two chemical series of substrate competitive PRMT5 inhibitors. Determination of co-crystal structures with several de novo designed hits aided in the identification of lead compounds that exhibited potent inhibition of PRMT5. Lead compounds AU-574 and AU-755 were highly active in inhibiting proliferation of a number of cell lines derived from solid tumors that correlated well with cellular H4R3Me2s inhibition, confirming the mechanism. Lead compounds exhibited desirable drug-like properties including solubility, permeability, lack of CYP inhibition, and pharmacokinetic exposure. In xenograft models of Z-138 (lymphoma) and H-358 (lung cancer), treatment with lead compounds resulted in significant tumor growth inhibition while correlating with tumor drug levels and modulation of H4R3Me2s as the pharmacodynamic effect. In summary, we have identified PRMT5 inhibitors with “best-in-class" drug-like properties including optimized permeability and antitumor efficacy. Evaluation of these lead compounds in in vitro selectivity screening and in toxicity studies in higher species is currently under way.

Citation Format: Dinesh Chikkanna, Sunil Kumar Panigrahi, Sujatha Rajagopalan, Srinivasa Raju Sammeta, Darshan Chawla, Pavithra S, Samiulla D.S, Angelene Prasanna, Priyabrata Chand, Kiran Aithal, Sai Sudheer Marri, Naveen Kumar, Srinivasa Rao Ganipisetty, Raju Mutyala, Kasieswara Rao, Thomas Antony, Girish Daginakatte, Anirudha Lakshminarasimhan, Mohan R, Narasihmarao K, Shekar Chelur, Chetan Pandit, Susanta Samajdar, Murali Ramachandra. Preclinical In vivo evaluation of efficacy, pharmacokinetics and pharmacodynamics of novel PRMT5 inhibitors in multiple tumor models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1392.

Abstract 2384: Preclinical evaluation of PD and efficacy of novel potent selective and orally bioavailable CDK12 covalent inhibitors in TNBC model

Cyclin-dependent kinase 12 (CDK12) is a transcription-associated kinase that participates in various cellular processes such as DNA damage response, splicing and pre-mRNA processing. In association with Cyclin K (CycK), CDK12 regulates transcription elongation by phosphorylating RNA polymerase II (RNAP II) at Serine 2 in the C-terminal domain (CTD). Overexpression of CDK12 in various tumor types suggests the possibility that CDK12 has oncogenic properties, similarly to other transcription-associated kinases. Considering its critical role in transcription and RNA processing CDK12 is emerging as a potential therapeutic target for cancer. Multiple series of potent and selective CDK12 covalent inhibitors were identified by iterative medicinal chemistry efforts and SAR-based approaches. Early compounds were optimized towards attaining good physicochemical properties, high potency, good selectivity and desirable pharmacokinetic profile to achieve anti-tumour activity. Very potent and highly selective CDK12 inhibitors have been identified from two distinct chemical series. The covalent mode of action for these biochemically potent compounds has been confirmed by CDK12 target engagement assay in the cellular context. These selective inhibitors showed significant anti-proliferative activity in TNBC and other cancer cell lines, which correlated with inhibition of pS2 (RNAP II), a bonafide CDK12 substrate and target engagement. In vivo target engagement, PD and efficacy data for optimized compounds with good oral bioavailability in a TNBC (HCC-70) xenograft model along with will be presented.

Citation Format: Ramulu Poddutoori, Sujatha Rajagopalan, Subhendu Mukherjee, Sivapriya Marappan, Samiulla D S, Sasirekha Sivakumar, Shilpa S. Nayak, Ravindra M. V, Hadianawala Murtuza, Devaraja T. S, Srinivas Kondela, Suraj Tgore, Amit A. Dhudashiya, Charamanna K. B, Thomas Antony, Girish Daginakatte, Sanjeev Giri, Shekar Chelur, Murali Ramachandra, Chetan Pandit, Susanta Samajdar. Preclinical evaluation of PD and efficacy of novel potent selective and orally bioavailable CDK12 covalent inhibitors in TNBC model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2384.

Abstract B165: Potent selective and orally bioavailable inhibition of CDK12 by novel covalent inhibitors

Background: Cyclin-dependent kinase 12 (CDK12) coordinately regulates the transcription, splicing, and alternative splicing of several large pre-mRNAs. Defective CDK12 kinase activity has been associated with genomic instability and downregulation of genes in the DNA damage response (DDR) pathway. In addition, CDK12 depletion impairs alternate splicing, a process being increasingly implicated in cancer progression. Associated with Cyclin K (CycK), CDK12 regulates transcription elongation by phosphorylating RNA polymerase II (RNAP II) at S2 in the C-terminal domain (CTD). Considering its role in transcription and RNA processing to maintain genomic stability/integrity in cancer, CDK12 is emerging as a potential therapeutic target to treat cancer. Experimental Procedures: Potent and selective CDK12 inhibitors were identified from multiple series by iterative medicinal chemistry efforts and SAR-based approaches. Early compounds were optimized towards attaining good physicochemical properties, high potency, good selectivity, and desirable pharmacokinetic profile to achieve antitumor activity.Summary: Very potent and highly selective compounds were identified from two distinct chemical series that are highly potent in inhibiting CDK12 in biochemical assays. Proving their covalent mode of action, these orally exposed compounds demonstrated robust engagement of CDK12 in a cellular context. Several of these potent and selective CDK12 inhibitors showed potent antiproliferative activity in various cancer cell lines derived from different origin, accompanied by robust CDK12 engagement and inhibition of pS2 (RNAP II). Further optimization of potency and ADME properties of initial lead compounds is in progress. Tolerability and efficacy studies are ongoing with selected early leads to test their impact on tumor growth inhibition in xenograft models. Conclusion: We identified novel, selective, and orally bioavailable covalent inhibitors of CDK12 from multiple distinct series with desirable drug-like properties, which are being evaluated for antitumor activity in xenograft models.

Citation Format: Ramulu Poddutoori, Sujatha Rajagopalan, Subhendu Mukherjee, Sivapriya Marappan, Samiulla D S, Venkateswarlu Kasturi, Sasirekha Sivakumar, Shilpa Nayak, Ravindra M V, Suraj Tgore, Amit Dhudashiya, Charamanna K B, Thomas Antony, Mahaboobi M, Sanjeev Giri, Girish C. Daginakatte, Shekar Chelur, Murali Ramachandra, Chetan Pandit, Susanta Samajdar. Potent selective and orally bioavailable inhibition of CDK12 by novel covalent inhibitors [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr B165.

Abstract A174: Novel inhibitors of protein arginine methyltransferase 5 (PRMT5) for the treatment of solid tumors

PRMT5 is a typical type II methyltransferase, transferring two methyl groups to arginine, leading to symmetric dimethylation of the substrate. It can symmetrically methylate histones H2AR3, H3R2, H3R8, and H4R3 and can also methylate many non-histone proteins contributing to tumorigenesis by regulating cell cycle progression, DNA repair, cell growth, apoptosis, and inflammation. Overexpression of PRMT5 is reported in several human malignancies including lymphoma, glioma, melanoma, lung, breast, ovarian, and prostate cancers. Elevated levels correlate with poor prognosis in NSCLC, ovarian cancers, and GBM. Therefore, PRMT5 is considered an attractive target for cancer therapy. We sought to discover and develop PRMT5 inhibitors with the “best-in-class” profile with an emphasis on improved brain permeability for their potential use in solid tumors including glioblastoma. Utilizing structure-guided drug design and SAR-based approaches, we have optimized two chemical series of substrate competitive PRMT5 inhibitors. Determination of co-crystal structures with several de novo designed hits aided in the identification of lead compounds that exhibited potent inhibition of PRMT5. Lead compounds were highly active in inhibiting proliferation of a number of cell lines derived from solid tumors that correlated well with cellular H4R3Me2s inhibition, confirming the mechanism. Lead compounds exhibited desirable drug-like properties including solubility, permeability, lack of CYP inhibition, and pharmacokinetic exposure. A substantial improvement in brain permeability over reported PRMT5 inhibitors was noted in rodent pharmacokinetic studies. In a xenograft model of lung cancer, treatment with lead compounds resulted in significant tumor growth inhibition while correlating with tumor drug levels and modulation of H4R3Me2s as the pharmacodynamic effect. In summary, we have identified PRMT5 inhibitors with “best-in-class" drug-like properties including optimized brain permeability and antitumor efficacy. Evaluation of the efficacy of these lead compounds in additional xenograft models including glioblastoma is currently under way.

Citation Format: Dinesh Chikkanna, Sunil Kumar Panigrahi, Sujatha Rajagopalan, Srinivasa Raju Sammeta, Anirudha Lakshminarasimhan, Mohan R, Narasihmarao K, Darshan Chawla, Harsha Bhat, Venkateswarlu Kasturi, Samiulla D.S, Angelene Prasanna, Kiran Aithal, Priyabrata Chand Chand, Naveen Kumar, Sai Sudheer Marri, Srinivasa Rao Ganipisetty, Kasieswara Rao N, Raju Mutyala, Nageswara Rao Neerukattu, Nithesh K, Ramya Amin, Priyanka Machhindra Gorade, Thomas Antony, Girish Daginakatte, Shekar Chelur, Chetan Pandit, Susanta Samajdar, Murali Ramachandra. Novel inhibitors of protein arginine methyltransferase 5 (PRMT5) for the treatment of solid tumors [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr A174.

Abstract LB-317: Identification of a novel preclinical candidate for CDK7 inhibition

Cyclin-dependent kinase 7 (CDK7) is an important constituent of the cellular transcriptional machinery, where it phosphorylates the C-terminal domain (CTD) of RNAP polymerase II (RNAPII). Because many tumor types are critically dependent on transcription for maintenance of their oncogenic state, pharmacological modulation of CDK7 kinase activity is considered as an approach to treat cancer. Multiple series of covalent CDK7 inhibitors were identified by iterative medicinal chemistry efforts and SAR based approach. These compounds were optimized towards attaining good physicochemical properties, high potency, good selectivity and desirable pharmacokinetic profile to achieve anti-tumor activity. We have now identified a pre-clinical candidate AU-BGB-002 which is highly potent in inhibiting CDK7 in biochemical as well as cellular assays while fully efficiently engaging the target. In a panel of kinases, AU-BGB-002 shows selectivity for CDK7. A panel of cell lines derived from a diverse set of indications are sensitive to AU-BGB-002. AU-BGB-002 exhibits excellent drug-like characteristics including solubility, permeability, metabolic stability and good oral bioavailability. When tested in a xenograft model, AU-BGB-002 treatment resulted in dose dependent tumor growth inhibition in AML xenograft model with tumor stasis at a dose of 10 mg/kg. Potent inhibiton of tumor growth was accompanied by complete target engagement and suppression of pS5RNAPII RNAPolII Ser5 phosphorylation in a parallel PK-PD study. Efficacy studies in additional xenograft models, advanced DMPK and toxicity studies are ongoing for this compound. In summary, we have identified a novel and selective CDK7 covalent inhibitor candidate with desirable drug-like properties that shows excellent efficacy in an AML xenograft model. Findings presented here support further development of AU-BGB-002 for the treatment of cancer.

Citation Format: Leena K. Satyam, Ramulu Poddutoori, Subhendu Mukherjee, Sivapriya Marappan, Sreevalsam Gopinath, Aravind Basavaraju, Lakshmi Narayana Kaza, Manoj Kumar Pothuganti, Shilpa Nayak, Nandish C, Amith A, Ravindra MV, Dabbeeru Madhu Babu, Nagaraju A, Suraj Tgore, Thomas Antony, Chetan Pandit, Murali Ramachandra, Shekar Chelur, Girish Daginakatte, Susanta Samajdar. Identification of a novel preclinical candidate for CDK7 inhibition [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-317. doi:10.1158/1538-7445.AM2017-LB-317

Abstract 5108: Potent small molecule compounds that selectively inhibit proliferation of ABC-DLBCL cell lines

Diffuse large B cell lymphoma (DLBCL), which accounts for 25% of all lymphomas cases, has been classified into molecular subtypes including germinal center B cell like (GCB) DLBCL, activated B cell-like (ABC) DLBCL, and primary mediastinal B cell lymphoma (PMBL). Among these subtypes, patients with ABC-DLBCLs have the worst prognosis because of the high chemo-resistance, and require effective therapies.

Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 (MALT1) protease activity is linked to the pathogenesis of ABC-DLBCL. Therefore, a focused library of covalent compounds selected based on molecular docking on the reported crystal structure was screened for selective sensitivity to ABC-DLBCL, but not GCB-DLBCL cell lines. Optimization of initial hits resulted in the identification of lead compounds with an anti-proliferative EC50 of &lt;100 nM selectively in ABC-DLBCL cell lines. Consistent with the previously reported role of MALT1 inhibitors, lead compounds also showed anti-proliferative activity in selected melanoma and NSCLC cell lines. The anti-proliferative activity of the lead compounds correlated well with the inhibition IL-6, a downstream marker of MALT1 signaling, in ABC-DLBCL cell line such as OCI-LY3. The lead compounds exhibited excellent drug-like properties including solubility, metabolic stability, lack of CYP inhibition, permeability and desired dose-dependent oral exposure in pharmacokinetic studies. In a repeated dose MTD study, the lead compounds showed good tolerability with an exposure multiple of &gt;10 over cellular EC50 for up to 8 hours. The lead compounds showed dose-dependent tumor growth inhibition in a xenograft model upon oral dosing.

In summary, we have identified novel and potent MALT1 inhibitors capable of selectively inhibiting proliferation of DLBCL cell lines with optimized drug-like properties including oral bioavailability. The data presented here strongly support further development of these compounds for DLBCL and other indications.

Citation Format: Leena Khare Satyam, Dinesh Chikkanna, Vinayak Khairnar, Manoj Pothuganti, Sunil Panigrahi, Anirudha Lakshminarasimhan, Narasimha Rao, Wesley Balasubramanian, Sandeep Patil, Sreevalsam Gopinath, Gunta Upendra, Jwala Nagaraj, Kiran Aithal, Vijay Ahuja, Sanjeev Giri, Chetan Pandit, Murali Ramachandra. Potent small molecule compounds that selectively inhibit proliferation of ABC-DLBCL cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5108. doi:10.1158/1538-7445.AM2017-5108

Abstract 339: Identification of novel covalent inhibitors of K-Ras G12C that are efficacious in a xenograft model of NSCLC

KRAS is the frequently mutated isoform in RAS driven cancers. The G12C mutation is more predominantly associated with various tumor types over other changes in K-Ras. Although direct targeting of RAS is very challenging, it is possible to selectively target G12C mutant K-Ras using a covalent approach. Mutant specific covalent inhibitors with high selectivity against wild type K-Ras and other GTPases are expected to lead to efficacy with a very high degree of tolerability. Here, we report identification of lead compounds from two distinct chemical series that selectively target K-Ras G12C. Molecular modeling based on the reported crystal structures aided in the identification of these compounds. Covalent binding of the lead compounds to K-Ras G12C was demonstrated by MALDI-TOF. Lead compounds were potent in selectively inhibiting proliferation of cell lines with K-Ras G12C mutation but not with wild type K-Ras. The anti-proliferative activity of the lead compounds correlated well with their potency in a cellular mechanistic assay. Lead compounds from both series exhibited excellent drug-like properties including solubility, metabolic stability, permeability lack of CYP inhibition and desired exposure in pharmacokinetic studies. In a xenograft model of NSCLC, the lead compound demonstrated dose-dependent tumor growth inhibition with excellent tolerability upon oral dosing. In summary, we have identified a novel, potent and selective K-Ras G12C inhibitor with optimized drug-like properties including oral bioavailability and efficacy in a NSCLC derived xenograft model. Toxicity evaluation is ongoing towards progressing the lead compound to the clinic.

Citation Format: Leena Khare Satyam, Dinesh Chikkanna, Aswani K. G, Vinayak V. Khairnar, Sreekanth Reddy, Vakkapatla Durgaprasad, Kowju Radhakrishna, Sunil K. Panigrahi, Anuradha Ramanathan, Kumari Mahasweta, Anirudha Lakshminarasimhan, Narasimha R. K, Vinutha R, Sreevalsam Gopinath, Suryakant Kumar, Mubarak H. Shah, Raghuveer Ramachandra, Kiran A. B, Chetan Pandit, Murali Ramachandra. Identification of novel covalent inhibitors of K-Ras G12C that are efficacious in a xenograft model of NSCLC. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 339.

Abstract 4798: Efficacy and safety of highly selective novel IRAK4 inhibitors for treatment of ABC-DLBCL

Interleukin-1 receptor associated kinases (IRAKs) are serine/threonine protein kinases belonging to the tyrosine-like kinase (TLK) family. IRAKs function as mediators of Toll-like receptor (TLR) and interleukin-1 receptor (IL-1R) signaling pathways and play an important role in innate immune signaling. TLR/IL-1R stimulation leads to recruitment of MYD88, an adaptor molecule, to the activated receptor complex, which then complexes with IRAK4 and activates IRAK1. TRAF6 is then activated by IRAK1 leading to NFkB activation. Recent studies have reported the occurrence of gain of function oncogenic mutation (L265P) in MYD88 in ∼30% of activated B cell diffuse large B-cell lymphoma(ABC DLBCL) and ∼90% of Waldenstrom's macroglobulinemia (WM) leading to constitutive activation of IRAK4 and NFkB pathway. Among the DLBCL subtypes (GCB, ABC DLBCL and PMBL), ABC DLBCL is the most refractory. Inhibition of constitutive IRAK4 signalling can be used as a therapeutic strategy to treat ABC DLBCL

Small molecule inhibitors of IRAK4 were synthesized based on hits originating from Aurigene's compound library. Structure guided drug design approach was used to further improve the potency. Lead compounds demonstrated moderate to very high selectivity towardsIRAK4 (S35 score of 0.03) when screened against a large panel of 329 kinases. Aurigene's lead compounds have excellent PK profile and good oral bioavailability in mice, leading to good in-vivo activity in TLR4 induced cytokine release model. Selected lead compounds were tested in a OCI-Ly3 xenograft model, which has a MYD88(L265P) mutation leading to constitutive activation of IRAK4 signaling. An advanced lead compound has demonstrated excellent efficacy in OCI-Ly3 model, with tumor stasis at low doses and tumor regression at higher doses. The compound is well tolerated and has a good therapeutic window as determined in a 14 day rodent toxicity study. In summary, a selective IRAK4 inhibitor has been identified with excellent efficacy and good safety profile.

Citation Format: Wesley Roy Balasubramanian, Venkateshwar Rao Gummadi, Kavitha Nellore, Subhendu Mukherjee, Sivapriya Marappan, Aravind Basavaraju, Bharathi Raja Ainan, Girish Daginakatte, Sreevalsam Gopinath, Sanjeev Giri, Thomas Antony, Shekar Chelur, Susanta Samajdar, Chetan Pandit, Murali Ramachandra. Efficacy and safety of highly selective novel IRAK4 inhibitors for treatment of ABC-DLBCL. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4798.

Respiratory manifestations and management in children with Common Variable Immunodeficiency

Common variable immunodeficiency is an antibody deficiency that usually presents in childhood with recurrent sino-pulmonary infections. Diagnostic delay is frequent and thus respiratory morbidity is common, ranging from recurrent suppurative bronchitis to bronchiectasis. Immunoglobulin replacement therapy is the mainstay of treatment, whilst prophylactic antibiotic therapy and muco-ciliary clearance are additional treatment options. This review examines the diagnosis and management of respiratory issues in children with CVID.

Discovery of selective RORγ inverse agonists and demonstration of efficacy in inflammatory disease models

The nuclear hormone receptor RORγ controls the differentiation of Th17 cells that plays a key pro-inflammatory role in a variety of autoimmune diseases. RORγ inverse agonists from multiple structural classes were discovered and screened in a RORγ radio-ligand binding assay as well as in a cell based reporter assay and functional effect was evaluated using primary mouse/human CD4+ve T-cells differentiation to Th17 cells. Pharmacokinetic profile of potent compounds was determined to support evaluation of efficacy as well as safety profile in rodents.

Lead compounds have demonstrated good activity (&lt; 100 nM) in reporter assay. Crystal structure of RORγ in complex with known inverse agonists as well as novel compounds, were solved to support lead optimization. Selected compounds demonstrated &gt;100 fold selectivity against RORα as well as other nuclear receptors with significant inhibition of IL-17 release in Th17 differentiation assay. Lead compounds have shown optimal physicochemical profile including good solubility and high free fraction, leading to excellent pharmacokinetic profile in mice and rats. Efficacy of lead compounds has been demonstrated in multiple disease models including asthma, psoriasis, Experimental auto immune encephalomyelitis and collagen induced arthritis. Potential lead candidates have been identified with excellent in-vitro safety profile including CEREP-44 safety panel, Ames test and cytotoxicity. One of the lead candidates has also demonstrated good therapeutic window as determined by a 7 day rat toxicity study.

Conclusions

We have identified structurally diverse small molecule inverse agonists of RORγ and have demonstrated efficacy in relevant disease models as well as good therapeutic window.

Abstract A72: Novel NAMPT inhibitors for the treatment of Pancreatic cancer

Pancreatic cancer is reported to be dependent on NAD salvage pathway for its growth and survival. Nicotinamide phosphoribosyl transferase (NAMPT), an enzyme that catalyzes the rate limiting step of NAD biosynthesis is over expressed in a number of cancers. Inhibition of NAMPT with first generation inhibitors has been demonstrated to result in anti-tumor efficacy in preclinical models. Clinical development of first generation NAMPT inhibitors has been hindered because of their poor pharmacological profile, high cytochrome inhibition and possibly mechanism-based toxicities. Therefore, our objective was to develop NAMPT inhibitors with the “best-in-class” profile with strategies for overcoming mechanism-based toxicities. Utilizing structure-guided drug design including determination of co-crystal structures and SAR-based approaches, we have identified a novel chemical series of inhibitors of NAMPT. Optimization of the series for transient target inhibition as a result of reduced binding strength coupled with desirable pharmacokinetic profile to minimize mechanism based toxicity resulted in identification of AU-4869 as the lead compound. AU-4869 showed potent cross-species activity and reduced strength of binding in comparison with first generation NAMPT inhibitors. Anti-proliferative activity of AU-4869 correlated well with NAD depletion in a pancreatic cancer cell line. The anti-proliferative activities were rescued in NAPRT-proficient cell lines with the addition of nicotinic acid due to the NAMPT independent salvage pathway for biosynthesis of NAD, confirming the mechanism of action through NAD depletion. AU-4869 exhibited desirable drug-like properties including solubility, permeability, metabolic stability, lack of CYP & hERG inhibition and pharmacokinetic exposure upon oral dosing. At well-tolerated doses, AU-4869 exhibited superior efficacy at MTD doses in mice xenograft models as compared to first generation inhibitors. Addition of nicotinic acid improved the tolerability of AU-4869 and reversed the effects of mechanism based toxicity in Rodents. Anti-tumor activities of AU-4869 in the presence of nicotinic acid in NAPRT-deficient pancreatic cancer models are currently being evaluated in preclinical models.

Citation Format: Dinesh Chikanna, Anirudha Lakshminarasimhan, Vinayak Khairnar, Sunil Panigrahi, Anuradha Ramanathan, Narasimha Rao, Kishore Narayanan, Sreevalsam Gopinath, Raghuveer Ramachandra, Shekar Chelur, Chetan Pandit, Murali Ramachandra. Novel NAMPT inhibitors for the treatment of Pancreatic cancer. [abstract]. In: Proceedings of the AACR Special Conference: Metabolism and Cancer; Jun 7-10, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(1_Suppl):Abstract nr A72.

Abstract C190: Potent and selective inhibition of CDK7 by novel covalent inhibitors

Cyclin-dependent kinase 7 (CDK7) is an important constituent of the cellular transcriptional machinery, where it phosphorylates the C-terminal domain (CTD) of RNAP polymerase II (RNAPII). Because many tumor types are critically dependent on transcription for maintenance of their oncogenic state, pharmacological modulation of CDK7 kinase activity is considered as an approach to treat cancer. Multiple series of CDK7 inhibitors were identified by iterative medicinal chemistry efforts and SAR based approach. Early compounds were optimized towards attaining good physicochemical properties, high potency, good selectivity and desirable pharmacokinetic profile to achieve anti-tumor activity. We have identified compounds from two distinct chemical series that are highly potent in inhibiting CDK7 in biochemical assays. These inhibitors demonstrate time-dependent inhibition of CDK7 indicating covalent nature of binding. The compounds showed potent anti-proliferative activity in cell lines derived from various tumor types and this was accompanied by CDK7 modulation in cells as monitored by pS5RNAPII levels. They have excellent drug-like characteristics including solubility, permeability, metabolic stability and good oral bioavailability. In a broad panel of kinases (332 kinase), selected compounds from both series showed good selectivity profile. Tolerability and efficacy studies are ongoing with selected early leads to test their impact on tumor growth inhibition in xenograft models. We have identified novel and selective CDK7 covalent inhibitors from two series with desirable drug-like properties, which are being evauated for anti-tumor activity in xenograft models.

Citation Format: Ramulu Poddutoori, Leena K. Satyam, Girish Daginakatte, Subhendu Mukherjee, Sivapriya Marappan, Sreevalsam Gopinath, Raghuveer Ramachandra, Anirudha Lakshminarasimhan, Manoj Pothuganti, Shilpa Nayak, Nandish C, Chandranath Naik, Ravindra MV, Madhu Dabbeeru, Thomas Antony, Chetan Pandit, Murali Ramachandra, Shekar Chelur, Susanta Samajdar. Potent and selective inhibition of CDK7 by novel covalent inhibitors. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C190.

Abstract C191: Efficacy of novel IRAK4 inhibitors in ABC-DLBCL and AML models

Interleukin-1 receptor associated kinases (IRAKs) are serine/threonine protein kinases belonging to tyrosine-like kinase (TLK) family. The IRAK family consists of IRAK1, IRAK2, IRAK3 and IRAK4 out of which only IRAK1 and IRAK4 exhibit kinase activity. IRAKs function as mediators of Toll-like receptor (TLR) and interleukin-1 receptor (IL-1R) signaling pathways and play an important role in innate immune signaling. Recent studies have reported the occurrence of oncogenic mutations in MYD88 in 30% of activated B cell diffuse large B-cell lymphoma (ABC DLBCL) and 90% of Waldenstrom's macroglobulinemia (WM) leading to constitutive activation of the IRAK4 and NFkB pathway. Recent studies have also highlighted the association of dysregulated innate immune signaling with Myelodysplastic syndrome (MDS) and Acute Myeloid leukaemia (AML). TLRs and their associated signal transducers are frequently overexpressed and/or constitutively activated in MDS. Overexpression and activation of IRAK1 is observed in AML. Thus IRAKs are attractive therapeutic targets for treatment of tumors with altered innate immune signaling such as ABC DLBCL and AML.

We have designed, synthesized and tested small molecule inhibitors of IRAK4 based on hits originating from Aurigene's compound library. We have identified a series of novel bicyclic heterocycles as potent inhibitors of IRAK-4 with moderate to very high selectivity (S35 score = 0.03) in a 329 kinase panel. Lead compounds were profiled in proliferation and mechanistic assays (p-IRAK1 and p-TAK1 inhibition) in appropriate ABC DLBCL/AML cell lines. Aurigene lead compounds demonstrate potent inhibition of cellular proliferation with a good correlation to inhibition of phosphorylation of signaling intermediates in mechanistic assays. Lead compounds exhibit excellent PK profile and good oral bioavailability in mice. Preliminary in-vitro toxicology studies indicate a clean safety profile. Selected compounds demonstrate excellent in-vivo efficacy in relevant tumor models with &gt;90% tumor growth inhibition and good in-vivo PD modulation. In summary, a series of potent and selective IRAK4 inhibitors have been discovered and are being evaluated for treatment of cancers with dysregulated innate immune signaling.

Citation Format: Venkateshwar Rao, Wesley Roy Balasubramanian, Kavitha Nellore, Sivapriya Marappan, Aravind Basavaraju, Bharathi Raja Ainan, Girish Daginakatte, Sreevalsam Gopinath, Sanjeev Giri, Thomas Antony, Shekar Chelur, Susanta Samajdar, Chetan Pandit, Murali Ramachandra. Efficacy of novel IRAK4 inhibitors in ABC-DLBCL and AML models. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C191.

Abstract 5367: Discovery of dihydro-isoxazole derivatives as novel inhibitors of NAMPT for the treatment of multiple myeloma

Nicotinamide phosphoribosyl transferase (NAMPT) is the enzyme that catalyzes the rate-limiting step in the salvage pathway of Nicotinamide Adenine Dinucleotide (NAD) biosynthesis. NAMPT is overexpressed in a number of cancers, and inhibition of NAMPT has been shown to result in anti-tumor efficacy in preclinical models. Clinical development to first generation NAMPT inhibitors has been hindered because of their poor pharmacological profile, high cytochrome inhibition and possibly mechanism-based toxicities. Therefore, we sought to develop NAMPT inhibitors with the “best-in-class” profile for overcoming mechanism-based toxicities and/or resistance to current therapies. Utilizing structure-guided drug design including determination of co-crystal structures and SAR-based approaches, we have identified a novel chemical series of inhibitors of NAMPT. Optimization of the series for transient target inhibition as a result of reduced binding strength coupled with desirable pharmacokinetic profile to minimize mechanism based toxicity resulted in identification of AU-4869 as the Lead compound.AU-4869 showed potent cross-species activity and reduced strength of binding in comparison with first generation NAMPT inhibitors. Anti-proliferative activity of AU-4869 correlated well with NAD depletion in multiple cell lines derived from multiple myeloma and Pancreatic cancers. The anti-proliferative activities were rescued in NAPRT-proficient cell lines with the addition of NA due to the NAMPT independent salvage pathway for biosynthesis of NAD, confirming the mechanism of action through NAD depletion. AU-4869 exhibited desirable drug-like properties including solubility, permeability, metabolic stability, lack of CYP & hERG inhibition and pharmacokinetic exposure upon oral dosing. At well-tolerated doses, AU-4869 exhibited superior efficacy at MTD doses in mice xenograft models (pancreatic cancer and multiple myeloma) as compared to FK866 and GNE-617.

In view of the ability of NAMPT inhibitors to enhance sensitivity to a number of targeted agents and overcome resistance to available therapies such as bortezomib in multiple myeloma, further pre-clinical development of AU-4869 for multiple myeloma is ongoing.

Citation Format: Dinesh Chikkanna, Anirudha Lakshminarasimhan, Vinayak Khairnar, Sunil panigrahi, Anuradha Ramanathan, Sumalatha Rani, Narasimha Rao, Karthikeyan S, Kishore Narayanan, Sreevalsam Gopinath, Raghuveer Ramachandra, Charamanna K B, Shekar Chelur, Chetan Pandit, Murali Ramachandra. Discovery of dihydro-isoxazole derivatives as novel inhibitors of NAMPT for the treatment of multiple myeloma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5367. doi:10.1158/1538-7445.AM2015-5367

Effect of general anesthesia on pulmonary function and clinical status on children with cystic fibrosis

INTRODUCTION

Children with cystic fibrosis (CF) receive general anesthesia (GA) for a variety of different procedures. Historical studies assessing risk of GA report a high risk of morbidity. There is a paucity of data evaluating the risk of currently available anesthetic agents. The aim of this study was to assess the effect of GA on clinical status and lung function on children with CF.

METHODS

Children with CF aged 8-18 years admitted for IV antibiotic treatment for a pulmonary exacerbation were invited to participate. Spirometry, forced oscillation technique (FOT), and CF clinical score (CFCS) were measured pre-GA, at 24 and 48 h post-GA. The nature and duration of the GA were recorded.

RESULTS

Twenty two patients were recruited of which 19 patients (mean age 11.4 years, range 8-18 years, 12 male) required GA. Typically, either propofol or sevoflurane was used as induction agent and maintenance of anesthesia was with sevoflurane. A laryngeal mask was used in most cases. FEV1 mean (±SD) pre-GA was 75.1% (±23.46) which decreased at 24 h to 74.8 (±23.0) and at 48 h to 74.3 (±20.5). FOT resistance and reactance decreased at 24 and 48 h from baseline. Changes in spirometry and CFCS were not statistically significant. Two adverse events were observed in this cohort.

CONCLUSION

The results suggest that children with mild to moderate CF lung disease do not experience significant deterioration in central or peripheral airway function following GA. The low rate of complications suggests an improved level of safety for children with CF with modern anesthesia compared with historical published data.

Abstract B210: Novel inhibitors of nicotinamide phosphoribosyl transferase and their evaluation in combination with bortezomib

Nicotinamide phosphoribosyl transferase (NAMPT) is the enzyme that catalyzes the rate limiting step in the salvage pathway of Nicotinamide Adenine Dinucleotide (NAD) biosynthesis. NAMPT is reported to be overexpressed in a number of cancer and inflammatory indications. Because of the requirement of NAD for a number of key biochemical pathways, inhibition of NAMPT has been shown to result in antitumor efficacy in preclinical models. NAMPT inhibitors have also been reported to enhance sensitivity to a number of targeted agents and overcome resistance to available therapies such as bortezomib resistance in multiple myeloma. In view of the sub-optimal profile of the reported first generation NAMPT inhibitors with respect to pharmacokinetics and drug-drug interaction, we sought to develop NAMPT inhibitors with the "best-in-class" profile for overcoming mechanism-based toxicities and/or resistance to current therapies. Utilizing structure-guided drug design and SAR-based approaches, we have optimized two chemical series of inhibitors of NAMPT. Determination of co-crystal structures with several de novo designed hits greatly aided in the identification of lead compounds that exhibited potent inhibition of NAMPT. Lead compounds were highly active in inhibiting proliferation that correlated well with cellular NAD depletion of cell lines derived from multiple myeloma, prostate and breast cancers. The anti-proliferative activities were rescued in NAPRT- proficient cell lines with the addition of NA due to the NAMPT independent salvage pathway for biosynthesis of NAD, confirming the mechanism of action through NAD depletion. Lead compounds exhibited desirable drug-like properties including solubility, permeability, metabolic stability, lack of CYP inhibition and pharmacokinetic exposure. In a xenograft model of pancreatic cancer, treatment with lead compounds resulted in regression of tumors with no signs of toxicity. Recent reports demonstrating the overexpression of NAMPT in bortezomib-resistant cells and a synergistic efficacy with a combination of NAMPT inhibitor and bortezomib against the resistant cells prompted us to evaluate the combination with our optimized leads. The combination of lead NAMPT inhibitors with bortezomib showed synergistic killing of cultured multiple myeloma cell lines. Evaluation of efficacy of the lead compounds as a single agent or in combination with bortezomib in xenograft models of multiple myeloma is currently underway. Modulation of NAD levels at lower doses of NAMPT inhibitors in combination with bortezomib could overcome the limitations such as mechanism-based toxicity and/or resistance of both these therapies and provide an effective treatment option for multiple myeloma.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B210.

Citation Format: Dinesh Chikkanna, Anirudha Lakshminarasimhan, Vinayak Khairnar, Sunil Panigrahi, Anuradha Ramanathan, Aparna Satyanandan, Narasimha Rao, S Karthikeyan, Kishore Narayanan, Sreevalsam Gopinath, Raghuveer Ramachandra, Hosahalli Subramanya, Chetan Pandit, Murali Ramachandra. Novel inhibitors of nicotinamide phosphoribosyl transferase and their evaluation in combination with bortezomib. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B210.

Identification of a novel series of orexin receptor antagonists with a distinct effect on sleep architecture for the treatment of insomnia

Dual orexin receptor (OXR) antagonists (DORAs) such as almorexant, 1 (SB-649868), or suvorexant have shown promise for the treatment of insomnias and sleep disorders in several recent clinical trials in volunteers and primary insomnia patients. The relative contribution of antagonism of OX1R and OX2R for sleep induction is still a matter of debate. We therefore initiated a drug discovery project with the aim of creating both OX2R selective antagonists and DORAs. Here we report that the OX2R selective antagonist 26 induced sleep in mice primarily by increasing NREM sleep, whereas the DORA suvorexant induced sleep largely by increasing REM sleep. Thus, OX2R selective antagonists may also be beneficial for the treatment of insomnia.

Festival food coma in cystic fibrosis

Children with cystic fibrosis liver disease and portal hypertension are at risk of developing acute hepatic encephalopathy. Even in the presence of normal synthetic liver function these children may have porto-systemic shunting. We report a case of an adolosecent who had cystic fibrosis liver disease and presented with life threatening hepatinc encephalopathy. This case illustrates that it is necessary to consider an appropriate dietary regimen in adolosecents with liver disease to prevent hepatic decompensation.

Abstract 5389: Novel inhibitors of nicotinamide phosphoribosyl transferase (NAMPT)

Nicotinamide phosphoribosyl transferase (NAMPT) is the enzyme that catalyzes the rate limiting step in the salvage pathway of Nicotinamide Adenine Dinucleotide (NAD) biosynthesis. NAMPT is reported to be overexpressed in a number of cancer and inflammatory indications. Because of the requirement of NAD as a co-factor or substrate for a number of key biochemical pathways including those catalyzed by PARP1, Sirtuins and ADP-ribosyl cyclase, inhibition of NAMPT has been shown to result in anti-tumor efficacy in preclinical models. Two NAMPT Inhibitors FK866/APO866 and GMX1778 are currently in clinical trials for oncology indications. In the presence of these clinical agents, cultured cell lines show development of resistance due to mutations underscoring the potential need for inhibitors from distinct chemical series.

Here, we report a structure-guided drug design based approach for identification of lead compounds from two chemical series selectively targeting NAMPT. Determination of co-crystal structures with several de novo designed hits greatly aided in the identification of lead compounds that exhibited potent inhibition of NAMPT against both wild type and resistance mutants (G217R and H191R) Lead compounds were highly active in inhibiting proliferation that correlated well with cellular NAD depletion in several cancer cell lines. Normal cells and selected cancer cell lines have an NAMPT independent salvage pathway for biosynthesis of NAD, which is dependent on nicotinic acid phosphoribosyltransferase (NAPRT) and Nicotinic acid (NA). The anti-proliferative activities were fully rescued in NAPRT- proficient cell lines with the addition of NA, confirming the mechanism of action through specific NAD depletion. Lead compounds from both series exhibited excellent drug-like properties including solubility, metabolic stability and permeability, and desired exposure in pharmacokinetic studies. Anti-tumor activities of these compounds including NA rescue in NAPRT-proficient tumor models are currently being evaluated in preclinical models.

Citation Format: Murali Ramachandra, Chetan Pandit, Hosahalli Subramanya, Dinesh Chikkanna, Anirudha Lakshminarasimhan, Vinayak Khairnar, Sunil Panigrahi, Anuradha Ramanathan, Aparna Satyanandan, Narasimha Rao, Arnab Bera, Kishore Narayanan, Sreevalsam Gopinath, Raghuveer Ramachandra. Novel inhibitors of nicotinamide phosphoribosyl transferase (NAMPT). [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5389. doi:10.1158/1538-7445.AM2013-5389

Respiratory problems in children with Down syndrome

Down syndrome is associated with a significant health burden, which is particularly apparent in young children who will frequently present with cardiac and respiratory problems. Respiratory presentations include problems related to structural abnormalities of the airways and lungs, glue ears, recurrent lower respiratory tract infections and obstructive sleep apnoea. These conditions are readily identifiable and able to be treated. An awareness of the breadth of respiratory problems and a plan to monitor patients with Down syndrome for their development has the potential to improve outcomes.

Synthesis and antimicrobial activity of novel fluorine containing 4-(substituted-2-hydroxybenzoyl)-1H-pyrazoles and pyrazolyl benzo[d]oxazoles

A series of fluorine containing 4-(substituted-2-hydroxybenzoyl) pyrazoles and pyrazolyl benzo[d]oxazoles were synthesized and evaluated for their antibacterial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis and antifungal activity against Candida albicans. The antibacterial activities were expressed as the minimum inhibitory concentration (MIC50) in microg/ml. The compounds 1-(3,4-difluorophenyl)-4-(5-fluoro-2-hydroxybenzoyl)-1H-pyrazole (4b), oxime derivatives such as 1-(3,4-difluorophenyl)-1H-pyrazol-4-yl)(2-hydroxy-4-methylphenyl)methanone oxime (5b) and (5-chloro-2-hydroxyphenyl)(1-(3,4-difluorophenyl)-1H-pyrazol-4-yl)methanone oxime (5e) exhibited promising activities against tested bacterial strains. Except compound 1-(3,4-difluorophenyl)-4-(2-hydroxybenzoyl)-1H-pyrazole (4d), none of the other compounds showed promising antifungal activity.