Crizotinib (PF02341066) as a ALK /MET inhibitor- Special Emphasis as a Therapeutic Drug Against Lung Cancer

Overcoming Chemoresistance in Cancer: The Promise of Crizotinib

Chemoresistance is a major obstacle in cancer treatment, often leading to disease progression and poor outcomes. It arises through various mechanisms such as genetic mutations, drug efflux pumps, enhanced DNA repair, and changes in the tumor microenvironment. These processes allow cancer cells to survive despite chemotherapy, underscoring the need for new strategies to overcome resistance and improve treatment efficacy. Crizotinib, a first-generation multi-target kinase inhibitor, is approved by the FDA for the treatment of ALK-positive or ROS1-positive non-small cell lung cancer (NSCLC), refractory inflammatory (ALK)-positive myofibroblastic tumors (IMTs) and relapsed/refractory ALK-positive anaplastic large cell lymphoma (ALCL). Crizotinib exists in two enantiomeric forms: (R)-crizotinib and its mirror image, (S)-crizotinib. It is assumed that the R-isomer is responsible for the carrying out various processes reviewed here The S-isomer, on the other hand, shows a strong inhibition of MTH1, an enzyme important for DNA repair mechanisms. Studies have shown that crizotinib is an effective multi-kinase inhibitor targeting various kinases such as c-Met, native/T315I Bcr/Abl, and JAK2. Its mechanism of action involves the competitive inhibition of ATP binding and allosteric inhibition, particularly at Bcr/Abl. Crizotinib showed synergistic effects when combined with the poly ADP ribose polymerase inhibitor (PARP), especially in ovarian cancer harboring BRCA gene mutations. In addition, crizotinib targets a critical vulnerability in many p53-mutated cancers. Unlike its wild-type counterpart, the p53 mutant promotes cancer cell survival. Crizotinib can cause the degradation of the p53 mutant, sensitizing these cancer cells to DNA-damaging substances and triggering apoptosis. Interestingly, other reports demonstrated that crizotinib exhibits anti-bacterial activity, targeting Gram-positive bacteria. Also, it is active against drug-resistant strains. In summary, crizotinib exerts anti-tumor effects through several mechanisms, including the inhibition of kinases and the restoration of drug sensitivity. The potential of crizotinib in combination therapies is emphasized, particularly in cancers with a high prevalence of the p53 mutant, such as triple-negative breast cancer (TNBC) and high-grade serous ovarian cancer (HGSOC).

Histone deacetylase inhibitors as sanguine epitherapeutics against the deadliest lung cancer

The back-breaking resistance mechanisms generated by lung cancer cells against epidermal growth factor receptor (EGFR), KRAS and Janus kinase 2 (JAK2) directed therapies strongly prioritizes the requirement of novel therapies which are perfectly tolerated, potentially cytotoxic and can reinstate the drug-sensitivity in lung cancer cells. Enzymatic proteins modifying the post-translational modifications of nucleosome-integrated histone substrates are appearing as current targets for defeating various malignancies. Histone deacetylases (HDACs) are hyperexpressed in diverse lung cancer types. Blocking the active pocket of these acetylation erasers through HDAC inhibitors (HDACi) has come out as an optimistic therapeutic recourse for annihilating lung cancer. This article in the beginning gives an overview about lung cancer statistics and predominant lung cancer types. Succeeding this, compendium about conventional therapies and their serious drawbacks has been provided. Then, connection of uncommon expression of classical HDACs in lung cancer onset and expansion has been detailed. Moreover, keeping the main theme in view this article deeply discusses HDACi in the context of aggressive lung cancer as single agents and spotlights various molecular targets suppressed or induced by these inhibitors for engendering cytotoxic effect. Most particularly, the raised pharmacological effects achieved on using these inhibitors in concerted form with other therapeutic molecules and the cancer-linked pathways altered by this procedure are described. The positive direction towards further heightening of efficacy and the pressing requirement of exhaustive clinical assessment has been proposed as a new focus point.

Comparison of MET gene amplification analysis by next-generation sequencing and fluorescence in situ hybridization

MET gene alterations are known to be involved in acquired resistance to epidermal growth factor receptor inhibition. MET amplifications present a potential therapeutic target in non-small cell lung cancer. Although next-generation sequencing (NGS) and fluorescence in situ hybridization (FISH) are conventionally used to assess MET amplifications, there are currently no clinically defined cut-off values for NGS, with FISH still being the gold standard. A collective of 20 formalin-fixed paraffin-embedded lung cancer tissue samples (mean age 64 years) were selected based on increased MET gene copy number (CNV) status or the presence of mutations detected by NGS (GeneReader, QIAGEN) and were further assessed by FISH (MET/CEN7, Zytomed). Of these, 17 tumor samples were MET-amplified and one patient was found to have a MET rearrangement by NGS, while two samples had no MET gene alteration. In contrast to the NGS result, FISH analysis showed only one highly amplified sample and 19 negative samples. The single highly amplified case detected by FISH was also positive by NGS with a fold change (FC) of 3.18 and a mean copy number (CN_{MV 10−100%}) of 20.5. Therefore, for the assessment of MET amplifications using the QIAGEN NGS workflow, we suggest detecting amplified cases with an FC value of ≥ 3.0 and a CN_{MV 10−100%} value of ≥ 20.0 by FISH. In summary, NGS allows for DNA- and RNA-based analysis of specific MET gene amplifications, point mutations or rearrangements.

Treatment Sequencing for Anaplastic Lymphoma Kinase-Rearranged Non-Small-Cell Lung Cancer

Non-small-cell lung cancer (NSCLC) accounts for about 85% of all lung cancer cases and is the leading cause of cancer-related deaths. Most NSCLC patients are diagnosed with advanced disease and require systemic treatment. Despite emerging advances in chemotherapy and immunotherapy, the prognosis of stage IV patients remains poor. However, the discovery of oncogenic driver mutations including mutations in the epidermal growth factor receptor (EGFR), the anaplastic lymphoma kinase (ALK) and others, characterize a subset of patients with the opportunity of targeted therapies. Fusions between the ALK and echinoderm microtubule-associated protein-like 4 (EML4) are present in ∼ 3-5% of patients with NSCLC. Several first-, second-, and third-generation ALK tyrosine kinase inhibitors (TKIs) have been developed in the last decade and have tremendously changed treatment options and outcomes of ALK-positive NSCLC patients. With increasing treatment options, treatment sequence decisions have become more and more complex. ALK-mutations, fusion variants, or activation of by-pass pathways result in treatment resistance during the course of treatment in nearly all patients. Mutation-guided treatment sequencing can lead to better outcomes, and re-biopsy or liquid-biopsy should be performed whenever possible in case of disease progression in ALK-rearranged patients. In the future, combinational treatment of ALK TKIs with other pathway-inhibitors might further improve patients' treatment options and outcomes. Here, we review the data for currently available ALK TKIs, discuss approaches of treatment sequencing, and give an outlook on emerging developments.

ALK inhibitors, resistance development, clinical trials

The treatment of advanced non-small-cell lung cancer (nsclc) has undergone a paradigm shift since the early 2000s. The identification of molecular subtypes of the disease, based on oncogenic drivers, has led to the development of personalized medicine and the ability to deliver molecularly targeted therapies to patients. In the 10 years that have elapsed since the discovery of the ALK gene in a patient with nsclc, several active drugs have moved rapidly from bench to bedside, and multiple others are currently in clinical trials. Those developments have led to important improvements in patient outcomes, while simultaneously raising key questions about the optimal treatment for ALK-positive nsclc. The inevitable emergence of resistance to alk-directed therapy is central to ongoing research and daily clinical practice for affected patients. In the present review, we highlight the current treatment landscape, the available and emerging clinical trials, and the evolving clinical decision-making in ALK-positive nsclc, with a focus on Canadian practice.

Crizotinib: from discovery to accelerated development to front-line treatment

Non-small-cell lung cancer (NSCLC) is associated with a poor prognosis and low survival rates, providing a strong rationale for the development of new treatment options. The discovery of ALK gene rearrangements in a subset of NSCLC specimens and the identification and development of the first-in-class ALK inhibitor crizotinib provided a personalised treatment option for patients with advanced ALK-positive NSCLC. Crizotinib demonstrated rapid and durable responses in advanced ALK-positive NSCLC patients in phase I and II studies, leading to accelerated FDA approval. Subsequent evaluation in phase III studies showed that crizotinib improved progression-free survival compared with platinum-based doublet chemotherapy in previously untreated patients and compared with pemetrexed or docetaxel in previously treated patients. Crizotinib was shown to have an acceptable safety profile and also to improve quality of life and symptom scores. Overall, crizotinib has been shown to provide a valuable first- and second-line treatment option and is now the first-line standard of care for patients with advanced ALK-positive NSCLC.