LDK378 inhibits the recruitment of myeloid-derived suppressor cells to spleen via the p38-GRK2-CCR2 pathway in mice with sepsis.

Myeloid-derived suppressor cells (MDSCs) are functionally immunosuppressive cells that are persistently increased in abundance and associated with adverse clinical outcomes in sepsis. Here, we investigated the therapeutic potential of an anaplastic lymphoma kinase inhibitor, LDK378, in cecal ligation and puncture (CLP)-induced polymicrobial sepsis and examined its effects on the recruitment of MDSCs. LDK378 significantly improved the survival of CLP-induced polymicrobial septic mice, which was paralleled by reduced organ injury, decreased release of inflammatory cytokines and decreased recruitment of MDSCs to the spleen. Importantly, LDK378 inhibited the migration of MDSCs to the spleen by blocking the CLP-mediated upregulation of CC chemokine receptor 2 (CCR2), a chemokine receptor critical for the recruitment of MDSCs. Mechanistically, LDK378 treatment blocked the CLP-induced CCR2 upregulation of MDSCs via partially inhibiting the phosphorylation of p38 and G-protein-coupled receptor kinase-2 (GRK2) in bone marrow MDSCs of septic mice. Furthermore, in vitro experiments also showed that lipopolysaccharide (LPS)-induced migration of MDSCs was similarly owing to the activation of GRK2 and upregulation of CCR2 by LPS, whereas the treatment with LDK378 partially blocked the LPS-induced phosphorylation of p38 and GRK2 and decreased the expression of CCR2 on the cell surface, therefore leading to the suppression of MDSC migration. Together, these findings unravel a novel function of LDK378 in the host response to infection and suggest that LDK378 could be a potential therapeutic agent for sepsis.

Discovery of novel tetrahydroisoquinoline-containing pyrimidines as ALK inhibitors.

Exploration of the two-position side chain of pyrimidine in LDK378 with tetrahydroisoquinolines (THIQs) led to discovery of 8 and 17 as highly potent ALK inhibitors. THIQs 8 and 17 showed encouraging in vitro and in vivo xenograft efficacies, comparable with those of LDK378. Although THIQ analogs (8a-o and 17a-i) prepared were not as active as their parent compounds, both 8 and 17 have significant inhibitory activities against various ALK mutant enzymes including G1202R, indicating that this series of compounds could be further optimized as useful ALK inhibitors overcoming the resistance issues found from crizotinib and LDK378.

ALK-positive non-small cell lung cancer: mechanisms of resistance and emerging treatment options.

Targeted therapy has emerged as an effective treatment option for certain molecular subsets of advanced stage non-small cell lung cancer (NSCLC). The discovery of the echinoderm microtubule-associated protein like 4-anaplastic lymphoma kinase (EML4-ALK) translocation as an oncogenic driver has led to the development of novel therapies with activity in vitro and in the clinic. The first-in-class tyrosine kinase inhibitor crizotinib is effective against ALK-positive NSCLC and is currently used as first-line or salvage therapy in the setting of advanced disease. However, resistance inevitably develops through a variety of mechanisms, including point mutations affecting the fusion protein, activation of bypass signaling pathways, copy number gain of ALK, and other means. Increased understanding of these pathways is essential for tailoring treatment choices to improve outcomes and minimize toxicities. Potent second-generation ALK inhibitors currently in trials are producing encouraging results in ALK-positive NSCLC, even in patients with acquired resistance to crizotinib. The success in identifying the ALK translocations and rapidly developing targeted drugs to exploit it paves the way for a better understanding of NSCLC biology and the quest to provide effective, personalized treatment for lung cancer patients.

Ceritinib for treatment of ALK-rearranged advanced non-small-cell lung cancer.

The anaplastic lymphoma kinase (ALK) gene plays a key role in the pathogenesis of selected tumors, including non-small-cell lung cancer (NSCLC). Patients with ALK-rearranged NSCLC are initially sensitive to the ALK inhibitor crizotinib but eventually become resistant, limiting its therapeutic potential. Ceritinib is an oral second-generation ALK inhibitor with greater preclinical antitumor potency than crizotinib in ALK-positive NSCLC. A Phase I trial of ceritinib in ALK-positive tumors demonstrated good activity in patients with advanced NSCLC, including those who had progressed on crizotinib. Adverse events are similar to those seen with other ALK tyrosine kinase inhibitors and are generally manageable. Ongoing trials are evaluating ceritinib in patients with ALK-rearranged NSCLC treated with prior chemotherapy and/or crizotinib.

Ceritinib (LDK378) prevents bone loss via suppressing Akt and NF-κB-induced osteoclast formation.

Background: Ceritinib is used for the treatment of patients with anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer (NSCLC), who are at the risk of developing bone metastasis. During bone metastasis, tumor cells release factors that induce osteoclast formation, resulting in osteolysis. However, the effect of ceritinib on osteoclast formation remains unclear. Methods: Osteoclastogenesis was induced to assess the effect of ceritinib on osteoclast formation and osteoclast-specific gene expression. Western blotting was used to examine the molecular mechanisms underlying the effect of ceritinib on osteoclast differentiation. An in vivo ovariectomized mouse model was established to validate the effect of ceritinib in suppressing osteoclast formation and preventing bone loss. Results: The differentiation of osteoclasts and the expression of osteoclast-specific genes were inhibited upon ceritinib stimulation. Ceritinib suppressed Akt and p65 phosphorylation during the receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclastogenesis. The administration of ceritinib to ovariectomized mice ameliorated trabecular bone loss by inhibiting osteoclast formation. Conclusions: Ceritinib is beneficial in preventing bone loss by suppressing osteoclastic Akt and nuclear factor κB (NF-κB) signaling.

LDK378 improves micro- and macro-circulation via alleviating STING-mediated inflammatory injury in a Sepsis rat model induced by Cecal ligation and puncture.

BACKGROUND: Sepsis is a systemic inflammatory response syndrome caused by severe infections. LDK378, a second-generation ALK inhibitor, exhibits a potential anti-inflammatory function against sepsis. Micro- and macro-circulatory dysfunctions are pivotal elements of the pathogenesis of severe sepsis and septic shock. We hypothesized that LDK378 can improve micro- and macro-circulation of septic rats, therefore improving the outcome of survival via blocking the ALK-STING pathway to attenuate inflammatory injuries. METHODS: A septic rat model was established by the cecal ligation and puncture (CLP) method. A total of 60 rats were randomized into three groups: a sham group, CLP group, and CLP + LDK378 group (n = 20 in each group). Five rats were randomly selected from each group for the mechanism study; the remaining 15 rats in each group were involved in a survival curve examination. A sidestream dark field video microscope was used to record sublingual microcirculation and mean arterial pressure (MAP) and levels of inflammatory cytokine secretion were examined at 6 h, 30 h, and 54 h after CLP surgery. Expressions of TANK binding kinase 1 (TBK1) and its downstream targets were determined, and histological alterations to the heart, lungs, and kidneys were examined at 54 h after CLP surgery. RESULTS: We found the group that received LDK378 treatment showed increased MAP levels compared to the CLP group at 30 h and 54 h. Meanwhile, LDK378 ameliorated the perfused small vessel density and microvascular flow index, decreased the expression of TNF-a and IL-6, and upregulated the expression of IL-10 in comparison with the CLP group. LDK378 injections also downregulated the expression of TBK1 and its downstream targets. Furthermore, LDK378 treatment significantly reduced sepsis-induced organ injuries, therefore improving survival rates. CONCLUSIONS: These findings demonstrate that LDK378 treatment can improve microcirculation and reduce organ injuries in CLP-induced septic rats via the regulation of inflammatory cytokine secretion and the downstream signaling components of the ALK-STING pathway.

Overcoming the resistance to crizotinib in patients with non-small cell lung cancer harboring EML4/ALK translocation.

The large knowledge learned in molecular biology specifically in the oncology field during the last ten years has resulted in fruitful results for the treatment of non-small cell lung cancer. The first pathway to be effectively targeted in lung cancer was the epidermal growth factor receptor. The acceptance of epidermal growth factor receptor mutation as a strong predictive biomarker in non-small cell lung carcinoma has encouraged the search for more targets. In 2011, regulatory entities granted conditional approval to an anaplastic lymphoma kinase inhibitor (crizotinib) based on an impressive overall response rate in previously treated non-small cell lung cancer patients whose tumors harbored EML4/ALK translocations. The landmark approval of crizotinib based on early promising clinical data highlights the remarkable success of molecular medicine in lung cancer therapeutics. The cumulative data developed after that approval has confirmed the appropriateness of this decision as recently reported phase III has now demonstrated. Unfortunately, resistance to this agent invariably develops and we now face the challenge of understanding several resistance pathways and overcoming them with new and more potent compounds. New agents in clinical development such as alectinib, LDK378, AP26113, and AUY922 have not only demonstrated promising activity in crizotinib resistant patients, but also crossing new pharmacokinetic boundaries in ALK inhibition as potent CNS penetration.

Ceritinib for the treatment of non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) represents the paradigm of personalized treatment in human cancer. Several oncogenic alterations with druggable potential have been identified, with ALK rearrangements representing one of the newest and most appealing. Crizotinib is now recognized as the standard of care in chemotherapy-pretreated ALK-positive NSCLC due to the positive results of a recently published trial. Unfortunately, no patient exposed to crizotinib can be cured, and after a median time of 1 year, resistance inevitably occurs. Overcoming resistance is the major challenge in clinical oncology and many molecules are currently under evaluation, including ceritinib (LDK-378). Ceritinib is an oral, potent, second-generation ALK inhibitor recently approved by the U.S. Food and Drug Administration. Preclinical data showed impressive antitumor activity against crizotinib-resistant clones, and based on available data, ceritinib could represent a suitable option in crizotinib-resistant NSCLC.