title: Insight into Discovery of Next Generation Reversible TMLR Inhibitors Targeting EGFR Activating and Drug Resistant T790M Mutants.
abstract: BACKGROUND
  Epidermal growth factor receptor (EGFR) is a well-recognised drug target exploited for treating non-small cell lung cancer (NSCLC). Gefitinib and erlotinib are first generation clinically employed inhibitors used against EGFR activating mutants. However, during course of treatment these inhibitors become ineffective due to the emergence of an acquired secondary mutation. Subsequently, in order to overcome non-responsiveness second and third generation inhibitors were designed having covalent bond and irreversible mode of action. However, these inhibitors were shown to be toxic. This led to the discovery of lead candidates with completely different mode of action and therapeutic efficacy.
  
  
  OBJECTIVE
  We have reviewed the recent efforts undertaken by researchers in discovering newer noncovalent reversible next generation inhibitors for treating NSCLC.
  
  
  METHODS
  We first studied the optimization steps and pharmacokinetic variables of the synthesised molecules. We also analysed bonds and interactions using PDB X-ray crystal structures as well as scaffold and selectivity analysis was undertaken.
  
  
  RESULTS
  We identified that ligand lipophilic efficiency driven potency is a preferable optimisation parameter for maintaining drug likeliness of the molecule. Also, few h-bonds were recognised as major players in affecting the binding of compound. The scaffold analysis revealed that ligand molecules with pyrimidine core exhibit higher inhibitory activity against TMLR, as well as higher selectivity with respect to other kinases.
  
  
  CONCLUSIONS
  Next generation reversible inhibitors exhibited unique binding mode and were found to occupy three major pockets (ribose pocket, back pocket and hinge region), which is critical for increasing the selectivity of the compound against TMLR mutants.
authors.affiliation: Bioinformatics Division, ICMR-Institute of Cytology and Preventive Oncology, I-7, Sector-39, Noida-201301. India.
authors.forename: Subhash Mohan
authors.initials: SM
authors.lastname: Agarwal
authors.affiliation: Bioinformatics Division, ICMR-Institute of Cytology and Preventive Oncology, I-7, Sector-39, Noida-201301. India.
authors.forename: Divyani
authors.initials: D
authors.lastname: Pal
authors.affiliation: Bioinformatics Division, ICMR-Institute of Cytology and Preventive Oncology, I-7, Sector-39, Noida-201301. India.
authors.forename: Mansi
authors.initials: M
authors.lastname: Gupta
authors.affiliation: Bioinformatics Division, ICMR-Institute of Cytology and Preventive Oncology, I-7, Sector-39, Noida-201301. India.
authors.forename: Ravi
authors.initials: R
authors.lastname: Saini
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry* / Q000494:pharmacology*; D001665:Binding Sites; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000235:genetics; D055808:Drug Discovery; D019008:Drug Resistance, Neoplasm / Q000187:drug effects* / Q000235:genetics; D066246:ErbB Receptors / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000077156:Gefitinib; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000235:genetics; D009154:Mutation; D047428:Protein Kinase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D011687:Purines / Q000737:chemistry / Q000494:pharmacology; D011728:Pyridones / Q000737:chemistry; D011743:Pyrimidines / Q000737:chemistry; D011799:Quinazolines / Q000737:chemistry / Q000494:pharmacology; D013329:Structure-Activity Relationship
chemical_list: D000970:Antineoplastic Agents; D047428:Protein Kinase Inhibitors; D011687:Purines; D011728:Pyridones; D011743:Pyrimidines; D011799:Quinazolines; C575621:SKLB1206; C512478:EGFR protein, human; D066246:ErbB Receptors; C030986:pyrimidine; D000077156:Gefitinib
keywords: EGFR; TMLR inhibitors; activating mutation; covalent inhibitors; reversible inhibitors; secondary mutant