PDZK1 suppresses TNBC development and sensitizes TNBC cells to erlotinib via the EGFR pathway.

Epidermal growth factor receptor (EGFR)-targeted drugs (erlotinib, etc.) are used to treat multiple types of tumours. EGFR is highly expressed in most triple-negative breast cancer (TNBC) patients. However, only a small proportion of TNBC patients benefit from EGFR-targeted drugs in clinical trials, and the resistance mechanism is unclear. Here, we found that PDZ domain containing 1 (PDZK1) is downregulated in erlotinib-resistant TNBC cells, suggesting that PDZK1 downregulation is related to erlotinib resistance in TNBC. PDZK1 binds to EGFR. Through this interaction, PDZK1 promotes EGFR degradation by enhancing the binding of EGFR to c-Cbl and inhibits EGFR phosphorylation by hindering EGFR dimerisation. We also found that PDZK1 is specifically downregulated in TNBC tissues and correlated with a poor prognosis in TNBC patients. In vitro and in vivo functional assays showed that PDZK1 suppressed TNBC development. Restoration of EGFR expression or kinase inhibitor treatment reversed the degree of cell malignancy induced by PDZK1 overexpression or knockdown, respectively. PDZK1 overexpression sensitised TNBC cells to erlotinib both in vitro and in vivo. In conclusion, PDZK1 is a significant prognostic factor for TNBC and a potential molecular therapeutic target for reversing erlotinib resistance in TNBC cells.

Development of erlotinib-loaded nanotransferosomal gel for the topical treatment of ductal carcinoma in situ.

Aims: This study was aimed to formulate erlotinib (ERL)-loaded transferosomal gel (ERL@TG) intended for topical application for the treatment of ductal carcinoma in situ. Materials & methods: The optimized process involved a thin-film hydration method to generate ERL-loaded transferosomes (ERL@TFS), which was incorporated into a carbopol gel matrix to generate ERL@TG. The optimized formulation was characterized in vitro followed by cytotoxicity evaluation on MCF-7 breast cancer cell lines and acute toxicity and skin irritation studies was performed in vivo. Results: In a comparative assessment against plain ERL, ERL@TG displayed enhanced efficacy against MCF-7 cell lines, reflected in considerably lower IC50 values with an enhanced safety profile. Conclusion: Optimized ERL@TG was identified as a promising avenue for addressing ductal carcinoma in situ breast cancer.

Despite progress, breast cancer remains a significant cause of death. This study aimed to revolutionize the treatment of noninvasive ductal carcinoma in situ, a type of breast cancer, by developing a special gel that can be applied directly to the breast. The developed gel was in the nanoform, a 'nanotransfersomal' gel that contained erlotinib, a potent drug for breast cancer. To ensure its effectiveness, we evaluated the erlotinib-loaded transfersomal gel through various tests. The results confirmed that the gel was nano-sized and loaded with a high amount of erlotinib. Animal studies were conducted to check if the prepared gel caused any skin irritation and interestingly, there was no irritation observed on the animals' skin. Furthermore, we treated breast cancer cells with the developed gel using a method called MTT assay and the results showed improved cell-killing activity in comparison to plain drug. In conclusion, this special gel represents a breakthrough in breast cancer treatment. It offers hope for better outcomes in the fight against this disease. This innovative approach involves directly applying the gel on the affected area topically to increase patient compliance and decreasing side effects of drugs. This could potentially transform ductal carcinoma in situ breast cancer treatment, bringing us closer to improved treatments and outcomes.

Monolayer culture alters EGFR inhibitor response through abrogation of microRNA-mediated feedback regulation.

Ex vivo drug screening is a potentially powerful tool for the future of cancer care, but the accuracy of results is contingent on the culture model. Both monolayer (2D) and spheroid (3D) culture systems offer advantages, but given the differences in mechanical environment, we hypothesized that that the suitability of one system over another would be critical for screening drugs with mechanical targets in mechanical tissues. HCC827 lung adenocarcinoma cells were challenged with EGFR tyrosine kinase inhibitors in monolayer and spheroid culture. RNA sequencing was performed on cells in both conditions to assess culture-induced transcriptional changes that could account for differences in drug response and differences in EGFR expression detected by immunostain. A microRNA microarray was performed to assess culture-induced differences in regulation of microRNA, and the impact of miR-146a-5p on drug response was verified by inhibition. Results were confirmed in human lung adenocarcinoma tissue. HCC827 spheroids were resistant to erlotinib and gefitinib, but significantly more sensitive in 2D culture. RNA-seq and immunostaining show a discrepancy in EGFR transcript and protein expression between the two conditions, which we attribute to miR-146a-5p. This microRNA targets EGFR and is differentially expressed between 2D and 3D culture. Inhibition of miR-146a-5p significantly increased erlotinib cytotoxicity, but validation in patient-derived spheroids suggests that the effect may be mutation-specific. Analysis of RNA-seq data suggests that cells in 2D culture become highly dependent on EGFR signaling to drive proliferation and cell spreading, resulting in a misleading level of sensitivity to EGFR TKIs, while the same cells in spheroid culture retain microRNA-driven EGFR feedback regulation that leaves them less vulnerable to EGFR inhibition. These findings underscore the need for close scrutiny of culture-induced effects on drug target regulation in model design for ex vivo drug screening.

Association of systemic inflammatory markers with prognosis in erlotinib-treated EGFR-mutant non-small cell lung cancer.

BACKGROUND: To evaluate the relationship of overall survival (OS) and progression-free survival (PFS) with the derived neutrophil-lymphocyte ratio (dNLR), neutrophil-lymphocyte ratio (NLR), lymphocyte-monocyte ratio (LMR), and platelet-lymphocyte ratio (PLR) in patients with epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC). METHODS: The study included 43 patients with EGFR-mutant metastatic NSCLC. The dNLR, NLR, LMR, and PLR values were calculated using the baseline complete blood counts before and after treatment with erlotinib. RESULTS: The NLR value had the best diagnostic test performance with a sensitivity of 91.3%. dNLR, NLR, LMR, and PLR were found to be significant for the prediction of OS and PFS. While the delta dNLR and NLR values were significant for OS, only the delta NLR value was significant for PFS. CONCLUSIONS: The dNLR, NLR, LMR, and PLR values were found to be significant in the prediction of OS and PFS in erlotinib-treated metastatic NSCLC. Further clinical studies are needed to determine the ideal target-specific tyrosine kinase inhibitor in cases of metastatic NSCLC presenting with the EGFR-activating mutation.

Erlotinib combination with a mitochondria-targeted ubiquinone effectively suppresses pancreatic cancer cell survival.

BACKGROUND: Pancreatic cancer is a leading cause of cancer-related deaths. Increased activity of the epidermal growth factor receptor (EGFR) is often observed in pancreatic cancer, and the small molecule EGFR inhibitor erlotinib has been approved for pancreatic cancer therapy by the food and drug administration. Nevertheless, erlotinib alone is ineffective and should be combined with other drugs to improve therapeutic outcomes. We previously showed that certain receptor tyrosine kinase inhibitors can increase mitochondrial membrane potential (Δψm), facilitate tumor cell uptake of Δψm-sensitive agents, disrupt mitochondrial homeostasis, and subsequently trigger tumor cell death. Erlotinib has not been tested for this effect. AIM: To determine whether erlotinib can elevate Δψm and increase tumor cell uptake of Δψm-sensitive agents, subsequently triggering tumor cell death. METHODS: Δψm-sensitive fluorescent dye was used to determine how erlotinib affects Δψm in pancreatic adenocarcinoma (PDAC) cell lines. The viability of conventional and patient-derived primary PDAC cell lines in 2D- and 3D cultures was measured after treating cells sequentially with erlotinib and mitochondria-targeted ubiquinone (MitoQ), a Δψm-sensitive MitoQ. The synergy between erlotinib and MitoQ was then analyzed using SynergyFinder 2.0. The preclinical efficacy of the two-drug combination was determined using immune-compromised nude mice bearing PDAC cell line xenografts. RESULTS: Erlotinib elevated Δψm in PDAC cells, facilitating tumor cell uptake and mitochondrial enrichment of Δψm-sensitive agents. MitoQ triggered caspase-dependent apoptosis in PDAC cells in culture if used at high doses, while erlotinib pretreatment potentiated low doses of MitoQ. SynergyFinder suggested that these drugs synergistically induced tumor cell lethality. Consistent with in vitro data, erlotinib and MitoQ combination suppressed human PDAC cell line xenografts in mice more effectively than single treatments of each agent. CONCLUSION: Our findings suggest that a combination of erlotinib and MitoQ has the potential to suppress pancreatic tumor cell viability effectively.

Mismatch Between Brain MRIs and 18 F-DOPA PET/CT : Impact on the Management of a Long Survivor With EGFR-Mutated Lung Adenocarcinoma.

ABSTRACT: After receiving erlotinib for 4 years, a man with advanced lung adenocarcinoma was treated with stereotactic radiotherapy for a left cerebellar brain metastasis. Local relapse of the metastasis was suspected 14 months after and confirmed on 18 F-DOPA PET. Three additional uptakes were described with no unequivocal MRI pathological signal. A second radiotherapy course was delivered. One year later, isolated local recurrence was suspected on a 3 T MRI, with a suspicious 18 F-DOPA uptake. Five additional 18 F-DOPA uptakes were described among which one increased between the 2 PETs. Because of these MRI/PET mismatches, a switch from erlotinib to osimertinib was preferred over surgery.

Dendritic cell vaccination in combination with erlotinib in a patient with inoperable lung adenocarcinoma: a case report.

BACKGROUND: Satisfactory treatment for patients with unresectable advanced lung cancer has not yet been established. We report a case of unresectable advanced lung cancer (stage IIIb: T2aN3M0) treated with a total of 15 doses of dendritic cells pulsed with a Wilms' tumor 1 and mucin 1 vaccine in combination with erlotinib, a small molecule epidermal growth factor receptor tyrosine kinase inhibitor, for more than 699 days without recurrence or metastasis. CASE PRESENTATION: A 63-year-old Korean woman was diagnosed with lung adenocarcinoma by pathology and computed tomography. The adenocarcinoma showed an epidermal growth factor receptor (EGFR) mutation, no anaplastic lymphoma kinase expression, and less than 1% expression of programmed death ligand 1. She received erlotinib alone for approximately 1 month. She then received erlotinib and the dendritic cells pulsed with Wilms' tumor 1 and mucin 1 vaccine. The diameter of the erythema at the vaccinated sites was 30 mm at 48 hours after the first vaccination. Moreover, it was maintained at more than 20 mm during the periods of vaccination. These results suggested the induction of antitumor immunity by the vaccine. Remarkably, the tumor size decreased significantly to 12 mm, a 65.7% reduction, after combined therapy with eight doses of the dendritic cells pulsed with Wilms' tumor 1 and mucin 1 vaccine and erlotinib for 237 days based on fluorodeoxyglucose uptake by positron emission tomography/computed tomography and computed tomography. Interestingly, after 321 days of combination therapy, the clinical findings improved, and no tumor was detected based on computed tomography. Validation of the tumor's disappearance persisted for at least 587 days after treatment initiation, without any indication of recurrence or metastasis. CONCLUSION: Standard anticancer therapy combined with the dendritic cells pulsed with Wilms' tumor 1 and mucin 1 vaccine may have therapeutic effects for such patients with unresectable lung adenocarcinoma.

Quantitative modeling of tumor dynamics and development of drug resistance in non-small cell lung cancer patients treated with erlotinib.

Insight into the development of treatment resistance can support the optimization of anticancer treatments. This study aims to characterize the tumor dynamics and development of drug resistance in patients with non-small cell lung cancer treated with erlotinib, and investigate the relationship between baseline circulating tumor DNA (ctDNA) data and tumor dynamics. Data obtained for the analysis included (1) intensively sampled erlotinib concentrations from 29 patients from two previous pharmacokinetic (PK) studies, and (2) tumor sizes, ctDNA measurements, and sparsely sampled erlotinib concentrations from 18 patients from the START-TKI study. A two-compartment population PK model was first developed which well-described the PK data. The PK model was subsequently applied to investigate the exposure-tumor dynamics relationship. To characterize the tumor dynamics, models accounting for intra-tumor heterogeneity and acquired resistance with or without primary resistance were investigated. Eventually, the model assumed acquired resistance only resulted in an adequate fit. Additionally, models with or without exposure-dependent treatment effect were explored, and no significant exposure-response relationship for erlotinib was identified within the observed exposure range. Subsequently, the correlation of baseline ctDNA data on EGFR and TP53 variants with tumor dynamics' parameters was explored. The analysis indicated that higher baseline plasma EGFR mutation levels correlated with increased tumor growth rates, and the inclusion of ctDNA measurements improved model fit. This result suggests that quantitative ctDNA measurements at baseline have the potential to be a predictor of anticancer treatment response. The developed model can potentially be applied to design optimal treatment regimens that better overcome resistance.

Pancreatic adenocarcinoma third line systemic treatments: a retrospective cohort study.

BACKGROUND: Chemotherapy for metastatic pancreatic adenocarcinoma (PDAC) primarily relies on FOLFIRINOX (LV5FU- irinotecan - Oxaliplatine) and Gemcitabine - Nab-Paclitaxel in the first-line setting. However, second-lines remain less well-defined and there is limited data regarding third-line treatments. The objective of our study was to determine the proportion of patients advancing to third line chemotherapy, to outline the various third-line chemotherapy regimens used in routine practice and to evaluate their respective efficacy. METHODS: A retrospective single-center cohort from 2010-2022 compiled baseline characteristics, treatment outcomes and survival of PDAC patients who received at least one chemotherapy line in a French tertiary-center. Overall survivals (OS) were analyzed using a Cox multivariable model. RESULTS: In total, 676 patients were included, with a median follow-up time of 69.4 months, (Interquartile Range (IQR) = 72.1). Of these, 251 patients (37%) that proceeded to 3rd-line chemotherapy. The median PFS in 3rd line was 2.03 months, [CI95%: 1.83, 2.36]. The median 3rd line overall survival was 5.5 months, [CI95%: 4.8, 6.3]. In multivariable analysis erlotinib-based chemotherapy was found to be deleterious (HR=2.38, [CI95%: 1.30, 4.34], p=0.005) compared to fluoropyrimidine-based chemotherapy in terms of 3rd line overall survival while gemcitabine monotherapy showed a tendency towards negative outcomes. First and 2nd line chemotherapies sequence didn't influence 3rd line outcome. CONCLUSION: In our cohort, one-third of treated patients proceeded to 3rd line chemotherapy resulting in a 5.5 months median 3rd line OS, consistent with treatments at advanced stage. Our results argue against the use of erlotinib and gemcitabine monotherapy.

Self-Assembly of Erlotinib-Platinum(II) Complexes for Epidermal Growth Factor Receptor-Targeted Photodynamic Therapy.

Due to cell mutation and self-adaptation, the application of clinical drugs with early epidermal growth factor receptor (EGFR)-targeted inhibitors is severely limited. To overcome this limitation, herein, the synthesis and in-depth biological evaluation of an erlotinib-platinum(II) complex as an EGFR-targeted anticancer agent is reported. The metal complex is able to self-assemble inside an aqueous solution and readily form nanostructures with strong photophysical properties. While being poorly toxic toward healthy cells and upon treatment in the dark, the compound was able to induce a cytotoxic effect in the very low micromolar range upon irradiation against EGFR overexpressing (drug resistant) human lung cancer cells as well as multicellular tumor spheroids. Mechanistic insights revealed that the compound was able to selectively degrade the EGFR using the lysosomal degradation pathway upon generation of singlet oxygen at the EGFR. We are confident that this work will open new avenues for the treatment of EGFR-overexpressing tumors.

Effectiveness and safety of afatinib, gefitinib, and erlotinib for treatment-naïve elderly patients with epidermal growth factor receptor-mutated advanced non-small-cell lung cancer: a multi-institute retrospective study.

BACKGROUND: In real-world practice, most patients with lung cancer are diagnosed when they are aged ≥65 years. However, clinical trials tend to lack data for the elderly population. Therefore, we aimed to describe the effectiveness and safety of afatinib, gefitinib, and erlotinib for elderly patients with epidermal growth factor receptor (EGFR)-mutated advanced non-small-cell lung cancer (NSCLC). METHODS: Treatment-naïve patients with EGFR-mutated advanced NSCLC were enrolled at many hospitals in Taiwan. Patient characteristics and the effectiveness and safety of afatinib, gefitinib, and erlotinib were compared. RESULTS: This study enrolled 1,343 treatment-naïve patients with EGFR-mutated advanced NSCLC, of whom 554 were aged <65 years, 383 were aged 65-74 years, 323 were aged 75-84 years, and 83 were aged ≥85 years. For elderly patients, afatinib was more effective, with a median progression-free survival (PFS) of 14.7 months and overall survival (OS) of 22.2 months, than gefitinib (9.9 months and 17.7 months, respectively) and erlotinib (10.8 months and 18.5 months, respectively; PFS: p = 0.003; OS: p = 0.026). However, grade ≥3 adverse events, including skin toxicities, paronychia, mucositis, and diarrhea, were more frequently experienced by patients receiving afatinib than those receiving gefitinib or erlotinib. CONCLUSIONS: This large retrospective study provides real-world evidence of the effectiveness and safety of EGFR-TKIs for elderly patients with EGFR-mutated advanced NSCLC, a population that is often underrepresented in clinical trials and real-world evidence. Afatinib was more effective as a first-line treatment than gefitinib or erlotinib for elderly patients with EGFR-mutated advanced NSCLC.

Radiation-Activated Cobalamin-Kinase Inhibitors for Treatment of Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most dismal diagnoses that a patient can receive. PDAC is extremely difficult to treat, as drug delivery is challenging in part due to the lack of vascularization, high stromal content, and high collagen content of these tumors. We have previously demonstrated that attaching drugs to the cobalamin scaffold provides selectivity for tumors over benign cells due to a high vitamin demand in these rapidly growing cells and an overexpression of transcobalamin receptors in a variety of cancer types. Importantly, we have shown the ability to deliver cobalamin derivatives to orthotopic pancreas tumors. Tyrosine kinase inhibitors have shown promise in treating PDAC as well as other cancer types. However, some of these inhibitors suffer from drug resistance, and as such, their success has been diminished. With this in mind, we synthesized the tyrosine kinase inhibitors erlotinib (EGFR) and dasatinib (Src) that are attached to this cobalamin platform. Both of these cobalamin-drug conjugates cause visible light-induced apoptosis, and the cobalamin-erlotinib conjugate (2) causes X-ray-induced apoptosis in MIA PaCa-2 cells. Both visible light and X-rays provide spatial control of drug release; however, utilizing X-ray irradiation offers the advantage of deeper tissue penetration. Therefore, we explored the utilization of 2 as a synergistic therapy with radiation in athymic nude mice implanted with MIA PaCa-2 tumors. We discovered that the addition of 2 caused an enhanced reduction in tumor margins in comparison with radiation therapy alone. In addition, treatment with 2 in the absence of radiation caused no significant reduction in tumor size in comparison with the controls. The cobalamin technology presented here allows for the spatial release of drugs in conjunction with external beam radiation therapy, potentially allowing for more effective treatment of deep-seated tumors with less systemic side effects.

Zebrafish drug screening identifies Erlotinib as an inhibitor of Wnt/ß-catenin signaling and self-renewal in T-cell acute lymphoblastic leukemia.

The Wnt/ß-catenin pathway's significance in cancer initiation, progression, and stem cell biology underscores its therapeutic potential. However, the clinical application of Wnt inhibitors remains limited due to challenges posed by off-target effects and complex cross-talk of Wnt signaling with other pathways. In this study, we leveraged a zebrafish model to perform a robust and rapid drug screening of 773 FDA-approved compounds to identify Wnt/ß-catenin inhibitors with minimal toxicity. Utilizing zebrafish expressing a Wnt reporter, we identified several drugs that suppressed Wnt signaling without compromising zebrafish development. The efficacy of the top hit, Erlotinib, extended to human cells, where it blocked Wnt/ß-catenin signaling downstream of the destruction complex. Notably, Erlotinib treatment reduced self-renewal in human T-cell Acute Lymphoblastic Leukemia cells, which rely on active ß-catenin signaling for maintenance of leukemia-initiating cells. Erlotinib also reduced leukemia-initiating cell frequency and delayed disease formation in zebrafish models. This study underscores zebrafish's translational potential in drug discovery and repurposing and highlights a new use for Erlotinib as a Wnt inhibitor for cancers driven by aberrant Wnt/ß-catenin signaling.

Targeting epidermal growth factor receptor signalling pathway: A promising therapeutic option for COVID-19.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is continuously producing new variants, necessitating effective therapeutics. Patients are not only confronted by the immediate symptoms of infection but also by the long-term health issues linked to long COVID-19. Activation of epidermal growth factor receptor (EGFR) signalling during SARS-CoV-2 infection promotes virus propagation, mucus hyperproduction, and pulmonary fibrosis, and suppresses the host's antiviral response. Over the long term, EGFR activation in COVID-19, particularly in COVID-19-induced pulmonary fibrosis, may be linked to the development of lung cancer. In this review, we have summarised the significance of EGFR signalling in the context of SARS-CoV-2 infection. We also discussed the targeting of EGFR signalling as a promising strategy for COVID-19 treatment and highlighted erlotinib as a superior option among EGFR inhibitors. Erlotinib effectively blocks EGFR and AAK1, thereby preventing SARS-CoV-2 replication, reducing mucus hyperproduction, TNF-α expression, and enhancing the host's antiviral response. Nevertheless, to evaluate the antiviral efficacy of erlotinib, relevant clinical trials involving an appropriate patient population should be designed.

Binding Thermodynamics of Fourth-Generation EGFR Inhibitors Revealed by Absolute Binding Free Energy Calculations.

The overexpression or mutation of the kinase domain of the epidermal growth factor receptor (EGFR) is strongly associated with non-small-cell lung cancer (NSCLC). EGFR tyrosine kinase inhibitors (TKIs) have proven to be effective in treating NSCLC patients. However, EGFR mutations can result in drug resistance. To elucidate the mechanisms underlying this resistance and inform future drug development, we examined the binding affinities of BLU-945, a recently reported fourth-generation TKI, to wild-type EGFR (EGFRWT) and its double-mutant (L858R/T790M; EGFRDM) and triple-mutant (L858R/T790M/C797S; EGFRTM) forms. We compared the binding affinities of BLU-945, BLU-945 analogues, CH7233163 (another fourth-generation TKI), and erlotinib (a first-generation TKI) using absolute binding free energy calculations. Our findings reveal that BLU-945 and CH7233163 exhibit binding affinities to both EGFRDM and EGFRTM stronger than those of erlotinib, corroborating experimental data. We identified K745 and T854 as the key residues in the binding of fourth-generation EGFR TKIs. Electrostatic forces were the predominant driving force for the binding of fourth-generation TKIs to EGFR mutants. Furthermore, we discovered that the incorporation of piperidinol and sulfone groups in BLU-945 substantially enhanced its binding capacity to EGFR mutants. Our study offers valuable theoretical insights for optimizing fourth-generation EGFR TKIs.

Brain metastasis, EGFR mutation subtype and generation of EGFR-TKI jointly influence the treatment outcome of patient with EGFR-mutant NSCLC.

Non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutation is brain metastasis (BM)-prone. We determined the impact of this hallmark, along with EGFR subtype and generation of tyrosine kinase inhibitor (TKI) treatment, on patients' outcome. 553 metastatic EGFR-mutant NSCLC patients received front-line EGFR-TKI treatment. Progression-free survival (PFS), overall survival (OS) and secondary T790M rate were analysed. BM was observed in 211 (38.2%) patients. BM (HR 1.20 [95% CI 0.99-1.48]; p = 0.053), ECOG PS 0-1 (HR 0.71 [95% CI 0.54-0.93]; p = 0.014) and afatinib treatment (HR 0.81 [95% CI 0.66-0.99]; p = 0.045) were associated with PFS. Afatinib-treated patients without BM demonstrated a significantly longer PFS (16.3 months) compared to afatinib-treated patients with BM (13.7 months) and to gefitinib/erlotinib-treated patients with (11.1 months) or without BM (14.2 months; p < 0.001). CNS-only progression trended higher in afatinib-treated patients. ECOG PS 0-1 (HR 0.41 [95% CI 0.31-0.56]; p < 0.001) and EGFR L858R mutation (HR 1.46 [95% CI 1.13-1.88]; p = 0.003), but not BM, were the predictors for OS. BM (OR 2.02 [95% CI 1.02-4.08]; p = 0.040), afatinib treatment (OR 0.26 [95% CI 0.12-0.50]; p < 0.001) and EGFR L858R mutation (OR 0.55 [95% CI 0.28-1.05]; p = 0.070) were associated with secondary T790M rate. In BM patients, gefitinib/erlotinib-treated ones with 19 deletion mutation and afatinib-treated ones with L858R mutation had the highest and the lowest T790M rate (94.4% vs. 27.3%, p < 0.001), respectively. BM and generation of EGFR-TKI jointly impact PFS and secondary T790M rate in patients with EGFR-mutant NSCLC, whereas OS was mainly associated with EGFR subtype.

Bayesian survival extrapolation for cost-effectiveness analysis: a case study of RELAY for ramucirumab in combination with erlotinib in the treatment of non-small-cell lung cancer.

AIM: Increasing trend for progression-free survival (PFS)-based primary endpoint in oncology has led to lack of mature overall survival (OS) data at the time of approval. To address this evidence gap in economic evaluations, we used a joint Bayesian approach to predict survival outcomes using immature OS data from the RELAY trial. METHODS: Patient data from RELAY and systematic literature review (SLR) of phase 3 randomized clinical trials with hazard ratio (HR) estimates of mature PFS and immature OS were considered. OS and PFS were analyzed individually using a univariate model; bivariate analysis was performed using a joint model based on modified Bayesian normal induced copula estimation model. First, a Bayesian univariate model incorporated informative priors based on predicted HR and acceleration factor for OS and PFS. Second, a Bayesian-based joint model of RELAY PFS and OS data was based on the correlation between PFS and OS established in trials of similar populations. Marginal distribution of PFS was used to estimate the same for OS. RESULTS: Publications (N = 122) of first-line treatments in patients with epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer were identified in the SLR, of which 36 trials were linked to RELAY. Twenty-six trials with HR data were used. The univariate model could predict OS with reduced uncertainty compared with the frequentist approach. In the joint model, the marginal OS distribution borrowed strength from the marginal PFS distribution through the established correlation coefficient. LIMITATIONS: Bayesian approach was successfully used in RELAY analysis but may not be universally applied to oncology trials due to the different associations of OS and PFS and different trial patient populations. CONCLUSIONS: We demonstrated that both the univariate and joint Bayesian models reduced uncertainty in predicting OS compared to frequentist method. The methodology introduced here will have potential applications in clinical decision-making for other oncology trials.

[Experimental study on the therapeutic effect and mechanism of erlotinib on non-proliferative diabetic retinopathy].

Objective: To investigate the therapeutic effect and mechanism of erlotinib, an epidermal growth factor receptor (EGFR) inhibitor, on non-proliferative diabetic retinopathy (NPDR). Methods: An experimental research was conducted. Human retinal Müller cells (RMC) were MIO-M1 cells from Moorfields Ophthalmology Hospital and the Institute of Ophthalmology at London University College. MIO-M1 cells were divided into normal, hypertonic, high glucose, high glucose+dimethyl sulfoxide (DMSO), high glucose+erlotinib 0.5 mmol/L, high glucose+erlotinib 1 mmol/L, and high glucose+erlotinib 2 mmol/L groups using a random number table method. Detection of the effect of erlotinib on the proliferation of MIO-M1 cells under high glucose conditions was performed by 5-ethynyl-2'-deoxyuridine (EdU) method. Western blotting (WB) was used to detect the effect of erlotinib on the activation markers of glial fibrillary acidic protein (GFAP) and glutamine synthetase (GS) protein levels in MIO-M1 cells under high glucose conditions. WB was used to detect the effect of erlotinib on the protein levels of nerve growth factor receptor (p75NTR), vimentin, and cell retinol binding protein (CRALBP) in RMC under high glucose conditions. MIO-M1 cells were divided into normal group, high glucose group, high glucose+DMSO group, and high glucose+erlotinib (1 mmol/L) group using random number table method. The effect of erlotinib on EGFR nuclear translocation under high glucose conditions was detected by cell immunofluorescence staining. Immunoprecipitation was used to detect the effect of erlotinib on the interaction between EGFR and transcription intermediate factor 2 (TIF2) in MIO-M1 cells under high glucose conditions. MIO-M1 cells were randomly divided into normal group, high glucose group, high glucose+DMSO group, high glucose+Myc-DDK empty body group, high glucose+erlotinib group, high glucose+erlotinib+human doublet protein group, high glucose+erlotinib+TIF2 plasmid group, and high glucose+erlotinib+human doublet protein+TIF2 plasmid group. Cell immunofluorescence staining was used to detect the effect of erlotinib on the binding of EGFR and TIF2 in MIO-M1 cells under high glucose conditions through the EGFR/TIF2 axis. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect the regulatory effect of EGFR and TIF2 binding on cyclin D1 transcription in MIO-M1 cells under high glucose conditions. The mouse model of diabetes retinopathy (DR) was constructed and divided into normal group, DR group, DR+DMSO group, DR+erlotinib 0.25 mg·kg-1·d-1 group, DR+erlotinib 0.5 mg·kg-1·d-1 group and DR+erlotinib 1 mg·kg-1·d-1 group. 25 mice in total, 5 in each group. Tissue immunofluorescence staining was used to detect the expression of RMC activation marker GFAP. The FITC-dextran injection experiment was used to detect the effect of erlotinib on retinal vascular leakage in a murine DR model. Results: Compared with the normal group (32.4%±3.0%), the proportion of EdU positive cells in RMC in the high glucose group (59.2%±3.8%) increased (P<0.001). Compared with the high glucose group (59.2%±3.8%), the proportion of EdU positive cells in the high glucose+1 mmol/L erlotinib group (37.6%±4.4%) decreased (P<0.001). Compared with the normal group, the expression of GFAP in RMC in the high glucose group increased (1 in the normal group, 2.27±0.11 in the high glucose group, P<0.001), while the expression of GS decreased (1 in the normal group, 0.32±0.03 in the high glucose group, P<0.001). 1 mmol/L erlotinib treatment reduced the expression of GFAP in RMC under high glucose conditions (1.32±0.13 and 2.27±0.11, respectively; P<0.001), and increased the expression of GS (0.71±0.06 and 0.32±0.03, respectively; P<0.001). The colocalization of EGFR and DAPI in RMC of the high glucose+1 mmol/L erlotinib group was lower than that of the high glucose group (52.2%±4.1% and 76.4%±5.7%, respectively; P<0.001). The expression of TIF2 or EGFR both increased while using EGF or TIF2 antibodies to precipitate TIF2 or EGFR under high glucose conditions compared to the normal group (1 in the normal group, 2.27±0.20 in the high glucose group, 2.17±0.21 in the EGFR, all P<0.05). And the expression of TIF2 (1.38±0.10) or EGFR (1.32±0.13) in the high glucose+erlotinib group was lower than that in the high glucose group (2.27±0.20) and the high glucose group (2.17±0.21) (all P<0.05). The colocalization of EGFR and TIF2 (17.2%±3.9%) and the mRNA level of Cyclin D1 (1.32±0.16) in the RMC of the high glucose+erlotinib group were lower than those in the high glucose group (54.6%±3.7% of EGFR and TIF2 colocalization ratio, 2.58±0.19 of Cyclin D1 mRNA level,all P<0.05). The high glucose+erlotinib+AREG (EGFR agonist) group, high glucose+erlotinib+Myc DDK-TIF2 plasmid group and high sugar+erlotinib+AREG+Myc-DDK-TIF2 plasmid group EGFR colocalization with TIF2 (colocalization ratios 24.1%±1.9%, 26.0%±2.3%, 35.3%±2.5%) and TIF2 mRNA levels (1.71±0.16, 1.72±0.18, 2.20±0.18). Compared with the high glucose+erlotinib group, The increases were statistically significant (all P<0.05). Compared to the normal group, the expression of GFAP in mouse retina tissue was increased in the DR group (1 in the normal group, 3.07±0.19 in the DR group, P<0.001), and 0.5 mg·kg-1·d-1 erlotinib (1.73±0.30) significantly reduced the expression of GFAP in the retina of DR group mice (P<0.05). Compared to the normal group (3.97±0.47), the DR group (23.13±2.15) showed an increase in fluorescein leakage, while the DR+erlotinib group (11.66±1.45) showed a significant decrease in leakage compared to the DR group (all P<0.05). Conclusions: Erlotinib inhibits the proliferation and activation of RMC induced by high glucose, inhibits the entry of EGFR into the nucleus, inhibits the binding of EGFR to TIF2 in RMC, and reduces the transcription of Cyclin D1 in RMC by inhibiting the interaction between EGFR and TIF2. At the same time, erlotinib inhibits the proliferation and activation of RMC in the mouse DR model, ameliorating retinal vascular leakage in mice. These results suggest that erlotinib inhibits the activation and proliferation of RMC by downregulating the EGFR/TIF2/Cyclin D1 pathway under high glucose conditions, thereby alleviating the progression of NPDR.