The impacts of CYP3A4 genetic polymorphism and drug interactions on the metabolism of lurasidone

The aim of this study was to investigate the impacts of 24 variants of recombinant human CYP3A4 and drug interactions on the metabolism of lurasidone. In vitro, enzymatic reaction incubation system of CYP3A4 was established to determine the kinetic parameters of lurasidone catalyzed by 24 CYP3A4 variants. Then, we constructed rat liver microsomes (RLM) and human liver microsomes (HLM) incubation system to screen potential anti-tumor drugs that could interact with lurasidone and studied its inhibitory mechanism. In vivo, Sprague-Dawley (SD) rats were applied to study the interaction between lurasidone and olmutinib. The concentrations of the analytes were detected by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). As the results, we found that compared with the wild-type CYP3A4, the relative intrinsic clearances vary from 355.77 % in CYP3A4.15 to 14.11 % in CYP3A4.12. A series of drugs were screened based on the incubation system, and compared to without olmutinib, the amount of ID-14283 (the metabolite of lurasidone) in RLM and HLM were reduced to 7.22 % and 7.59 %, and its IC50 were 18.83 ± 1.06 μM and 16.15 ± 0.81 μM, respectively. At the same time, it exerted inhibitory effects both through a mixed mechanism. When co-administration of lurasidone with olmutinib in rats, the AUC(0-t) and AUC(0-∞) of lurasidone were significantly increased by 73.52 % and 69.68 %, respectively, while CLz/F was observably decreased by 43.83 %. In conclusion, CYP3A4 genetic polymorphism and olmutinib can remarkably affect the metabolism of lurasidone.

Spectroscopic, molecular docking and dynamic simulation studies of binding between the new anticancer agent olmutinib and human serum albumin

In this study, the interaction between human serum albumin (HSA), which is the key bio-distributor of exogenous and endogenous compounds in the human bloodstream, and HM61713 (Olmutinib; OMB), which is used as an anticancer drug, is examined by multiple spectroscopic techniques (steady-state fluorescence, UV spectrophotometry, synchronous, and 3 D fluorescence) combined with molecular docking and molecular dynamic simulation investigations. The fluorescence results clearly demonstrated quenching in HSA fluorescence in the existence of OMB indicating the formation of complex and have also shown that the interaction is static. Fluorescence spectroscopy was used to obtain the binding constant values that revealed a strong interaction between the HSA and OMB at 298 K with a binding constant of 7.39x10⁴ M^-1 suggesting strong interaction. OMB binds to HSA at site I (IIA). Electrostatic forces and H-bonding were the main binding forces of main bonding between HSA and OMB as revealed by docking and thermodynamic results.Communicated by Ramaswamy H. Sarma.

Safety, tolerability, and anti-tumor activity of olmutinib in non-small cell lung cancer with T790M mutation: A single arm, open label, phase 1/2 trial

OBJECTIVES

The aim of this phase 1/2 study was to evaluate the safety, tolerability, pharmacokinetics and antitumor activity of olmutinib in patients with epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) who had failed ≥ 1 previous line of EGFR-tyrosine kinase inhibitor (TKI) therapy.

MATERIALS AND METHODS

Phase 1 consisted of dose-escalation and four dose-expansion parts (1: olmutinib 300 mg once daily; 2A: 800 mg once daily [EGFR T790 M mutation-positive patients]; 2B: 500 mg twice daily [EGFR T790 M mutation-positive]; 3: 800 mg once daily [EGFR T790 M mutation-negative]). In phase 2, EGFR T790 M mutation-positive patients received olmutinib 800 mg once daily. Data from expansion part 2A and phase 2 were integrated (`pooled phase 2'). Each olmutinib cycle was 21 days. Outcomes included: tumor response, treatment-emergent adverse events (TEAEs), pharmacokinetic parameters.

RESULTS

Overall, 272 patients received at least one olmutinib dose: dose-escalation (n = 66), expansion parts (n = 165), phase 2 (n = 41). In pooled phase 2, the overall objective response rate, confirmed by independent review, was 55.1% (38/69 evaluable patients; 95% CI, 42.6-67.1). All responses were partial responses; 23 patients had stable disease. Estimated median progression-free survival was 6.9 (95% CI, 5.6-9.7) months; estimated median overall survival was not reached. The most frequent treatment-related AEs were diarrhea (59.2% of patients), pruritus (42.1%), rash (40.8%), and nausea (39.5%).

CONCLUSION

Olmutinib showed effective clinical activity with a manageable safety profile, indicating therapeutic potential for T790M-positive NSCLC patients who have failed ≥ 1 previous line of EGFR-TKI therapy.

Olmutinib Induced Lichen Planus Like Eruption

Drug induced lichen planus like eruption is an uncommon cutaneous adverse effect of several drugs. This appears symmetric eruption of erythematous or violaceous plaques resembling lichen planus on the trunk and extremities. A 50-year-old male presented with scaly, violaceous plaques and dusky brown macules on whole body. For four months, the patient was treated with olmutinib, an oral, third-generation epidermal growth factor receptor-tyrosine kinase inhibitor. In May 2016, olmutinib received its first global approval in South Korea for the treatment of patients with locally advanced or metastatic epidermal growth factor receptor T790M mutation-positive non-small cell lung cancer. The biopsy specimen from the patient showed features of lichen planus. We diagnosed him with olmutinib-induced lichen planus like eruption. He was treated with oral methylprednisolone and topical desoxymethasone 0.25% ointment. At the same time, olmutinib dose was decreased to three-fourths of this patient's starting dose. After that, the cutaneous lesions improved.

Olmutinib (HM61713) reversed multidrug resistance by inhibiting the activity of ATP-binding cassette subfamily G member 2 in vitro and in vivo

Overexpressing of ATP-binding cassette (ABC) transporters is the essential cause of multidrug resistance (MDR), which is a significant hurdle to the success of chemotherapy in many cancers. Therefore, inhibiting the activity of ABC transporters may be a logical approach to circumvent MDR. Olmutinib is an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), which has been approved in South Korea for advanced EGFR T790M-positive non-small cell lung cancer (NSCLC). Here, we found that olmutinib significantly increased the sensitivity of chemotherapy drug in ABCG2-overexpressing cells. Furthermore, olmutinib could also increase the retention of doxorubicin (DOX) and rhodamine 123 (Rho 123) in ABC transporter subfamily G member 2 (ABCG2)-overexpressing cells. In addition, olmutinib was found to stimulate ATPase activity and inhibit photolabeling of ABCG2 with [¹²⁵I]-iodoarylazidoprazosin (IAAP). However, olmutinib neither altered ABCG2 expression at protein and mRNA levels nor blocked EGFR, Her-2 downstream signaling of AKT and ERK. Importantly, olmutinib enhanced the efficacy of topotecan on the inhibition of S1-MI-80 cell xenograft growth. All the results suggest that olmutinib reverses ABCG2-mediated MDR by binding to ATP bind site of ABCG2 and increasing intracellular chemotherapeutic drug accumulation. Our findings encouraged to further clinical investigation on combination therapy of olmutinib with conventional chemotherapeutic drugs in ABCG2-overexpressing cancer patients.

Third generation EGFR TKIs in EGFR-mutated NSCLC: Where are we now and where are we going

The therapeutic landscape of Non Small Lung Cancer (NSCLC) has been profoundly changed over the last decade with the clinical introduction of Epidermal Growth Factor Receptor (EGFR) tyrosine kinase inhibitors (TKIs) and the discovery of EGFR activating mutations as the major predictive factor to these agents. Despite impressive clinical activity against EGFR-mutated NSCLCs, the benefit seen with 1st and 2nd generation EGFR TKIs is usually transient and virtually all patients become resistant. Several different mechanisms of acquired resistance have been reported to date, but the vast majority of patients develop a secondary exon 20 mutation in the ATP-binding site of EGFR, namely T790M. The discovery of mutant-selective EGFR TKIs that selectively inhibit EGFR-mutants, including T790M-harboring NSCLCs, while sparing EGFR wild type, provide the opportunity for overcoming the major mechanism of acquired resistance to 1st and 2nd generation EGFR TKIs, with a relatively favorable toxicity profile. The development of this novel class of EGFR inhibitors poses novel challenges in the rapidly evolving therapeutic paradigm of EGFR-mutated NSCLCs and the next few years will witness the beginning of a new era for EGFR inhibition in lung cancer. The aim of this paper is to provide a comprehensive overview of the increasing body of data emerging from the ongoing clinical trials with this promising novel therapeutic class of EGFR inhibitors.

Update on recent preclinical and clinical studies of T790M mutant-specific irreversible epidermal growth factor receptor tyrosine kinase inhibitors

The first- and second-generation epidermal growth factor receptor tyrosine kinase inhibitors (1/2G EGFR-TKIs) gefitinib, erlotinib, and afatinib have all been approved as standard first-line treatments for advanced EGFR mutation-positive non-small cell lung cancer. The third-generation (3G) EGFR-TKIs have been developed to overcome the EGFR T790M mutation, which is the most common mechanism of acquired resistance to 1/2G EGFR-TKI treatment. This resistance mutation develops in half of the patients who respond to 1/2G EGFR-TKI therapy. The structures of the novel 3G EGFR-TKIs are different from those of 1/2G EGFR-TKIs. Particularly, 3G EGFR-TKIs have lower affinity to wild-type EGFR, and are therefore associated with lower rates of skin and gastrointestinal toxicities. However, many of the adverse events (AEs) that are observed in patients receiving 3G EGFR-TKIs have not been observed in patients receiving 1/2G EGFR-TKIs. Although preclinical studies have revealed many possible mechanisms for these AEs, the causes of some AEs remain unknown. Many mechanisms of resistance to 3G EGFR-TKI therapy have also been reported. Here, we have reviewed the recent clinical and preclinical developments related to novel 3G EGFR-TKIs, including osimertinib, rociletinib, olmutinib, EGF816, and ASP8273.