Efficacy and Safety of Re-administration of Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitor (EGFR-TKI) After EGFR-TKI-Induced Interstitial Lung Disease (CS-Lung-005).

PURPOSE: This study investigated the safety and efficacy of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) re-administration after recovery from EGFR-TKI-induced interstitial lung disease (ILD). METHODS: This multicenter retrospective study collected data from consecutive advanced NSCLC patients who underwent EGFR-TKI re-administration after recovery from EGFR-TKI-induced ILD. RESULTS: Fifty-eight patients were registered. The grades of initial TKI-induced ILD were grade 1 to 4. TKIs used for re-administration were erlotinib for 15 patients, osimertinib for 15, gefitinib for 14, afatinib for 13 patients, and dacomitinib for 1 patient. ILD recurred in 13 patients (22.4%), comprising 3 patients with grade 1, 6 patients with grade 2, and 4 patients with grade 3. No significant associations were found between ILD recurrence and age, smoking history, performance status, time from initial ILD to TKI re-administration, or concomitant corticosteroid use. However, the incidence of ILD recurrence was high in cases of repeated use of gefitinib or erlotinib or first time use of osimertinib at TKI re-administration. The ILD recurrence rate was lowest in patients treated with first time use of gefitinib (8%) or erlotinib (8%), followed by patients treated with repeated use of osimertinib (9%). The response rate, median progression-free survival by TKI re-administration, and median overall survival were 55%, 9.6 and 84.8 months, respectively. CONCLUSION: This study showed that EGFR-TKI re-administration is a feasible and effective treatment for patients who recovered from EGFR-TKI-induced ILD. Our results indicate that re-administration of EGFR-TKI is an important option for long-term prognosis after recovery from EGFR-TKI-induced ILD.

Efficacy of gilteritinib in comparison with alectinib for the treatment of ALK-rearranged non-small cell lung cancer.

Gilteritinib is a multitarget tyrosine kinase inhibitor (TKI), approved for the treatment of FLT3-mutant acute myeloid leukemia, with a broad range of activity against several tyrosine kinases including anaplastic lymphoma kinase (ALK). This study investigated the efficacy of gilteritinib against ALK-rearranged non-small cell lung cancers (NSCLC). To this end, we assessed the effects of gilteritinib on cell proliferation, apoptosis, and acquired resistance responses in several ALK-rearranged NSCLC cell lines and mouse xenograft tumor models and compared its efficacy to alectinib, a standard ALK inhibitor. Gilteritinib was significantly more potent than alectinib, as it inhibited cell proliferation at a lower dose, with complete attenuation of growth observed in several ALK-rearranged NSCLC cell lines and no development of drug tolerance. Immunoblotting showed that gilteritinib strongly suppressed phosphorylated ALK and its downstream effectors, as well as mesenchymal-epithelial transition factor (MET) signaling. By comparison, MET signaling was enhanced in alectinib-treated cells. Furthermore, gilteritinib was found to more effectively abolish growth of ALK-rearranged NSCLC xenograft tumors, many of which completely receded. Interleukin-15 (IL-15) mRNA levels were elevated in gilteritinib-treated cells, together with a concomitant increase in the infiltration of tumors by natural killer (NK) cells, as assessed by immunohistochemistry. This suggests that IL-15 production along with NK cell infiltration may constitute components of the gilteritinib-mediated antitumor responses in ALK-rearranged NSCLCs. In conclusion, gilteritinib demonstrated significantly improved antitumor efficacy compared with alectinib against ALK-rearranged NSCLC cells, which can warrant its candidacy for use in anticancer regimens, after further examination in clinical trial settings.

Role of phosphate transporter PiT-2 in the pathogenesis of primary brain calcification.

Primary brain calcification (PBC), also known as idiopathic basal ganglia calcification (IBGC), primary familial brain calcification (PFBC) and so on, is a rare intractable disease characterized by abnormal mineral deposits, including mostly calcium in the basal ganglia, thalamus, and cerebellum. The causative gene of familial PBC is SLC20A2, which encodes the phosphate transporter PiT-2. Despite this knowledge, the molecular mechanism underlying SLC20A2-associated PBC remains unclear. In the present study, we investigated whether haploinsufficiency or a dominant-negative mechanism reduced Pi uptake in two PiT-2 variants (T115 M and R467X). We demonstrated that the presence of T115 M or R467X had no dominant-negative effect on Pi transport activity of wild-type (WT). In addition, the subcellular localization of R467X completely differed from that of WT, indicating that there is no interaction between R467X and WT. Conversely, T115 M and WT showed almost the same localization. Therefore, we examined the interaction between T115 M and WT using the bioluminescence resonance energy transfer (BRET) method. Although WT and T115 M interact with each other, T115 M does not inhibit WT's Pi transport activity. These results suggest that the role of SLC20A2 in the pathogenesis of PBC may involve decreased intracellular Pi uptake by a haploinsufficiency mechanism rather than a dominant-negative mechanism; agents promoting PiT-2 dimerization may be promising potential therapeutic agents for PBC.

Identification of targetable kinases in idiopathic pulmonary fibrosis.

BACKGROUND: Tyrosine kinase activation plays an important role in the progression of pulmonary fibrosis. In this study, we analyzed the expression of 612 kinase-coding and cancer-related genes using next-generation sequencing to identify potential therapeutic targets for idiopathic pulmonary fibrosis (IPF). METHODS: Thirteen samples from five patients with IPF (Cases 1-5) and eight samples from four patients without IPF (control) were included in this study. Six of the thirteen samples were obtained from different lung segments of a single patient who underwent bilateral pneumonectomy. Gene expression analysis of IPF lung tissue samples (n = 13) and control samples (n = 8) was performed using SureSelect RNA Human Kinome Kit. The expression of the selected genes was further confirmed at the protein level by immunohistochemistry (IHC). RESULTS: Gene expression analysis revealed a correlation between the gene expression signatures and the degree of fibrosis, as assessed by Ashcroft score. In addition, the expression analysis indicated a stronger heterogeneity among the IPF lung samples than among the control lung samples. In the integrated analysis of the 21 samples, DCLK1 and STK33 were found to be upregulated in IPF lung samples compared to control lung samples. However, the top most upregulated genes were distinct in individual cases. DCLK1, PDK4, and ERBB4 were upregulated in IPF case 1, whereas STK33, PIM2, and SYK were upregulated in IPF case 2. IHC revealed that these proteins were expressed in the epithelial layer of the fibrotic lesions. CONCLUSIONS: We performed a comprehensive kinase expression analysis to explore the potential therapeutic targets for IPF. We found that DCLK1 and STK33 may serve as potential candidate targets for molecular targeted therapy of IPF. In addition, PDK4, ERBB4, PIM2, and SYK might also serve as personalized therapeutic targets of IPF. Additional large-scale studies are warranted to develop personalized therapies for patients with IPF.

VEGFR2 blockade augments the effects of tyrosine kinase inhibitors by inhibiting angiogenesis and oncogenic signaling in oncogene-driven non-small-cell lung cancers.

Molecular agents targeting the epidermal growth factor receptor (EGFR)-, anaplastic lymphoma kinase (ALK)- or c-ros oncogene 1 (ROS1) alterations have revolutionized the treatment of oncogene-driven non-small-cell lung cancer (NSCLC). However, the emergence of acquired resistance remains a significant challenge, limiting the wider clinical success of these molecular targeted therapies. In this study, we investigated the efficacy of various molecular targeted agents, including erlotinib, alectinib, and crizotinib, combined with anti-vascular endothelial growth factor receptor (VEGFR) 2 therapy. The combination of VEGFR2 blockade with molecular targeted agents enhanced the anti-tumor effects of these agents in xenograft mouse models of EGFR-, ALK-, or ROS1-altered NSCLC. The numbers of CD31-positive blood vessels were significantly lower in the tumors of mice treated with an anti-VEGFR2 antibody combined with molecular targeted agents compared with in those of mice treated with molecular targeted agents alone, implying the antiangiogenic effects of VEGFR2 blockade. Additionally, the combination therapies exerted more potent antiproliferative effects in vitro in EGFR-, ALK-, or ROS1-altered NSCLC cells, implying that VEGFR2 inhibition also has direct anti-tumor effects on cancer cells. Furthermore, VEGFR2 expression was induced following exposure to molecular targeted agents, implying the importance of VEGFR2 signaling in NSCLC patients undergoing molecular targeted therapy. In conclusion, VEGFR2 inhibition enhanced the anti-tumor effects of molecular targeted agents in various oncogene-driven NSCLC models, not only by inhibiting tumor angiogenesis but also by exerting direct antiproliferative effects on cancer cells. Hence, combination therapy with anti-VEGFR2 antibodies and molecular targeted agents could serve as a promising treatment strategy for oncogene-driven NSCLC.

Beneficial effect of erlotinib and trastuzumab emtansine combination in lung tumors harboring EGFR mutations.

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) is the standard therapy for non-small cell lung cancer (NSCLC) harboring EGFR mutations, but the resistance is inevitable. The drug-tolerant persister cancer cells are thought to be involved in the resistance. We recently reported that HER2 expression had a negative impact on time-to-treatment-failure in patients with EGFR mutant NSCLC. In this study, we hypothesized that HER2 might be a potential target for alternative combination therapy in NSCLC harboring EGFR mutations. In vitro study showed that the level of HER2 expression had no correlation with the sensitivity to EGFR-TKI, erlotinib but showed some correlation with HER2-inhibitor, ado-trastuzumab emtansine (T-DM1) in multiple EGFR-mutant lung cancer cell lines. In addition, HER2 expression was increased in persister cancer cells in 11-18 cell line harboring EGFR L858R or HCC827 cell line harboring EGFR exon 19 deletion after the exposure to erlotinib in vitro and in vivo. The combination of erlotinib and T-DM1 showed a superior inhibitory effect on cell proliferation compared with those of the erlotinib or T-DM1 alone in either 11-18 or HCC827 cells in vitro. The combination therapy also induced a significantly greater inhibitory effect on tumor growth in xenograft model in mice transplanted with either 11-18 or HCC827 cells compared with erlotinib alone or T-DM1 alone. No body weight loss was observed in these mice. These results suggested that the combination therapy with EGFR-TKI and T-DM1 might be a potentially promising strategy for treating lung cancer harboring EGFR mutations.

SLC20A2 variants cause dysfunctional phosphate transport activity in endothelial cells induced from Idiopathic Basal Ganglia Calcification patients-derived iPSCs.

Idiopathic Basal Ganglia Calcification (IBGC) is a rare neuropsychiatric illness also known as Fahr's disease or Primary Familial Brain Calcification (PFBC). IBGC is caused by SLC20A2 variants, which encodes the inorganic phosphate (Pi) transporter PiT-2, a transmembrane protein associated with Pi homeostasis. We have reported novel SLC20A2 variants in the Japanese population and established an induced pluripotent stem cells (iPSCs) from an IBGC patient carrying a SLC20A2 variant. To investigate the effect of these SLC20A2 variants identified in our previous study, we used Chinese hamster ovary (CHO) cells expressing these variant proteins using the Flp-In system (Flp-In CHO cells), and showed that variant SLC20A2 proteins significantly disrupted the Pi transport activity in Flp-In CHO cells. Endothelial cells (ECs) represent important target cells for elucidating the pathology of IBGC. Using patient-derived iPSCs in this study, we differentiated these cells into ECs and found no significant difference in their differentiation capacity into ECs compared with control iPSCs. However, the Pi transport activity of IBGC patient-derived iPS-ECs was significantly decreased compared with that of control iPS-ECs without changing the gene expression of the other SLC 20 family members. We confirmed that SLC20A2 variants caused the loss of function of the Pi transport activity in both Flp-In CHO cells and disease-specific iPSCs. This is the first report to show an in vitro model of iPSCs in IBGC with patient-identified SLC20A2 variants. These useful tools will help in elucidating IBGC pathogenesis and can be used for screening drug candidates.

A Case of Dupilumab-Induced Diffuse Alveolar Hemorrhage.

Eosinophilic pneumonia is a known side effect of dupilumab; however, diffuse alveolar hemorrhage has not yet been reported in association with dupilumab. We herein report a case of diffuse alveolar hemorrhage caused by dupilumab. A 57-year-old man with severe asthma was unable to discontinue oral steroids and thus was prescribed dupilumab. The patient was admitted to the hospital four weeks after treatment because of suspected eosinophilic pneumonia. Bronchoscopy revealed diffuse alveolar hemorrhage characterized by hemosiderin-phagocytic macrophages in the bronchoalveolar lavage fluid without eosinophils. The steroid dosage improved the respiratory status and resolved the infiltrate shadow. Dupilumab may thus cause diffuse alveolar hemorrhage, which can be differentiated using bronchoscopy.

Ramucirumab-induced ascites with endothelial growth factor receptor mutation-positive non-small cell lung cancer: Two case reports.

Ramucirumab (RAM) has been approved for the treatment of non-small cell lung cancer (NSCLC). Here, we report two cases of RAM-induced ascites with epidermal growth factor receptor-mutant NSCLC. Patient 1, a 72-year-old man, developed ascites 20 months after erlotinib (ERL) and RAM administration, which resolved after their discontinuation and performing paracentesis. Patient 2, an 83-year-old woman, developed ascites 9 months after ERL and RAM administration, which resolved after RAM discontinuation and furosemide administration. Ramucirumab administration can cause ascites due to increased hepatic sinusoidal pressure. Clinicians should be aware of RAM-induced ascites in patients with NSCLC and should appropriately manage it.

Efficacy of immune checkpoint inhibitors according to programmed cell death-ligand 1 expression in patients with non-small cell lung cancer and brain metastasis: A real-world prospective observational study.

INTRODUCTION: Studies have shown the antitumor efficacy of immune checkpoint inhibitors (ICI) in patients with non-small cell lung cancer (NSCLC) and brain metastases (BM). However, it is unclear whether the efficacy of ICI is similar between patients with and without BM. It is yet unclear whether the efficacy of ICI in patients with BM increases with higher levels of programmed cell death-ligand 1 (PD-L1) expression, as observed in patients without BM. METHODS: We compared the outcomes of ICI treatment between patients with and without BM using a cohort containing 1741 prospectively enrolled patients with lung cancer. We investigated whether there were differences in the outcomes of ICI based on PD-L1 expression levels between these patients. RESULTS: We enrolled 240 patients with NSCLC with or without BM who were treated with ICI or both chemotherapy and ICI. There were no significant differences in overall survival (OS) between all patients with or without BM (p = 0.489). However, OS was significantly shorter in patients with BM than in those without in the PD-L1 ≥ 50% group (16.5 M vs. 30.6 M, p = 0.003) but not in the PD-L1 ≥ 1% or negative group. BM was an independent poor prognostic factor for OS (hazard ratio: [95% confidence interval], 2.045; [1.058-3.953], p = 0.033) in the PD-L1 ≥ 50% group. CONCLUSION: Our study indicated that the outcomes of patients with or without BM treated with ICI were not significantly different. The efficacy of ICI in patients with PD-L1 expression ≥50% would be lower in patients with BM than in those without.

Clinical characteristics of patients treated with immune checkpoint inhibitors in EGFR-mutant non-small cell lung cancer: CS-Lung-003 prospective observational registry study.

PURPOSE: Immune checkpoint inhibitors (ICIs) are ineffective against epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC). This study aimed to investigate the clinical characteristics of patients who were treated or not treated with ICIs, and of those who benefit from immunotherapy in EGFR-mutant NSCLC. METHODS: We analyzed patients with unresectable stage III/IV or recurrent NSCLC harboring EGFR mutations using a prospective umbrella-type lung cancer registry (CS-Lung-003). RESULTS: A total of 303 patients who met the eligibility criteria were analyzed. The median age was 69 years; 116 patients were male, 289 had adenocarcinoma, 273 had major mutations, and 67 were treated with ICIs. The duration of EGFR-TKI treatment was longer in the Non-ICI group than in the ICI group (17.1 vs. 12.7 months, p < 0.001). Patients who received ICIs for more than 6 months were categorized into the durable clinical benefit (DCB) group (24 patients), and those who received ICIs for less than 6 months into the Non-DCB group (43 patients). The overall survival in the DCB group exhibited longer than the Non-DCB group (69.3 vs. 47.1 months), and an equivalent compared to that in the Non-ICI group (69.3 vs. 68.9 months). Multivariate analysis for time to next treatment (TTNT) of ICIs showed that a poor PS was associated with a shorter TTNT [hazard ratio (HR) 3.309; p < 0.001]. Patients who were treated with ICIs and chemotherapy combination were associated with a longer TTNT (HR 0.389; p = 0.003). In addition, minor EGFR mutation was associated with a long TTNT (HR 0.450; p = 0.046). CONCLUSION: ICIs were administered to only 22% of patients with EGFR-mutated lung cancer, and they had shorter TTNT of EGFR-TKI compared to other patients. ICI treatment should be avoided in EGFR mutated lung cancer with poor PS but can be considered for lung cancer with EGFR minor mutations. Pathological biomarker to predict long-term responders to ICI are needed.

A case of synovitis-acne-pustulosis-hyperostosis-osteitis syndrome with right pleural effusion.

A 79-year-old man presented with fatigue and right shoulder pain. Computed tomography revealed right pleural effusion and osteosclerosis of the sternoclavicular joint. There were no signs of malignancy or infection in the pleural fluid studies. His bone scintigraphy exhibited the "bull's head sign." Despite the absence of skin lesions, he was diagnosed with synovitis-acne-pustulosis-hyperostosis-osteitis (SAPHO) syndrome. Remission was achieved after treatment with non-steroidal anti-inflammatory drugs and oral prednisolone. SAPHO syndrome causes pleural effusion, even in patients without skin lesions. Bone scintigraphy should be considered in the workup for patients with unexplained pleural effusion.

A case of successful desensitization treatment with tepotinib after tepotinib-induced rash.

Tepotinib is one of the key drugs for MET exon 14-skipping mutation-positive non-small cell lung cancer (NSCLC). The main adverse event of tepotinib treatment is edema. Rash is a rare adverse event, affecting only 0.7% of patients. We report a case of successful desensitization after skin rash caused by tepotinib. A 61-year-old male was treated with tepotinib 500 mg as second-line therapy for NSCLC with MET exon 14-skipping mutation. Treatment was discontinued on day 12 due to grade 3 erythema throughout the body. After improvement of the skin rash, he was started on 250 mg tepotinib with an oral antihistamine and topical steroid. Treatment was discontinued on day 11 due to skin rash exacerbation. One month of treatment-free follow-up showed skin rash improvement but lung carcinoma growth. Tepotinib desensitization therapy was started at a dose of 12.5 mg and gradually increased to 250 mg/day. The patient has since continued tepotinib treatment without skin rashes. Desensitization therapy may be effective for managing skin rash due to tepotinib.

PD-1 blockade augments CD8+ T cell dependent antitumor immunity triggered by Ad-SGE-REIC in Egfr-mutant lung cancer.

OBJECTIVES: No immunotherapeutic protocol has yet been established in never-smoking patients with lung cancer harboring driver oncogenic mutations, such as epidermal growth factor receptor (EGFR) mutations. The immunostimulatory effect of Ad-REIC, a genetically engineered adenovirus vector expressing a tumor suppressor gene, reduced expression in immortalized cells (REIC), has been investigated in clinical trials for various solid tumors. However, the immunostimulatory effect of the Ad-REIC in EGFR-mutant lung cancer with a non-inflamed tumor microenvironment (TME) has not been explored. MATERIALS AND METHODS: We used a syngeneic mouse model developed by transplanting Egfr-mutant lung cancer cells into single or double flanks of C57BL/6J mice. Ad-SGE-REIC, a 2nd-generation vector with an enhancer sequence, was injected only into the tumors from one flank, and its antitumor effects were assessed. Tumor-infiltrating cells were evaluated using immunohistochemistry or flow cytometry. The synergistic effects of Ad-SGE-REIC and PD-1 blockade were also examined. RESULTS: Injection of Ad-SGE-REIC into one side of the tumor induced not only a local antitumor effect but also a bystander abscopal effect in the non-injected tumor, located on the other flank. The number of PD-1+CD8+ T cells increased in both injected and non-injected tumors. PD-1 blockade augmented the local and abscopal antitumor effects of Ad-SGE-REIC by increasing the number of CD8+ T cells in the TME of Egfr-mutant tumors. Depletion of CD8+ cells reverted the antitumor effect, suggesting they contribute to antitumor immunity. CONCLUSION: Ad-SGE-REIC induced systemic antitumor immunity by modifying the TME status from non-inflamed to inflamed, with infiltration of CD8+ T cells. Additionally, in Egfr-mutant lung cancer, this effect was enhanced by PD-1 blockade. These findings pave the way to establish a novel combined immunotherapy strategy with Ad-SGE-REIC and anti-PD-1 antibody for lung cancer with a non-inflamed TME.

A case of immunoglobulin G4-Related disease with pleural effusion, requiring exclusion of tuberculous pleurisy.

Immunoglobulin G4 (IgG4)-related pleurisy is a rare type of IgG4-related disease. We present the case of a 69-year-old woman with left pleural effusion and elevated adenosine deaminase levels. Initially, tuberculous pleuritis was suspected; however, the bacterial cultures and polymerase chain reaction test results for tuberculosis were negative. Thoracoscopic pleural biopsy revealed dense lymphocytic infiltrates with large numbers of IgG4-positive plasma cells. The ratio of IgG4-positive to IgG-positive plasma cells exceeded 40%. The patient was diagnosed with IgG4-related disease.

First and repeat rebiopsy for detecting EGFR T790M mutation in non-small-cell lung cancer: CS-Lung-003 prospective observational registry study.

PURPOSE: Osimertinib is still essential for the treatment of epidermal growth factor receptor (EGFR)-T790M-positive non-small-cell lung cancer (NSCLC) even in a relapsed setting, which suggests the importance of rebiopsy. The clinical value of repeat rebiopsy in patients with NSCLC who are T790M-negative on a first rebiopsy remains unclear. In this study, we examined the status of the first rebiopsy and evaluated the frequency of repeat rebiopsy of T790M-negative tumors detected by the first rebiopsy. METHODS: We reviewed 144 patients with NSCLC with major EGFR mutations, but not T790M, who received first- or second-generation EGFR tyrosine kinase inhibitors (TKIs), registered in the prospective, umbrella-type lung cancer patient registry (CS-Lung-003). RESULTS: Overall, 63 patients (44%) underwent the first rebiopsy. In the first rebiopsy, 51 (81%) and 12 (19%) of 63 underwent histological/cytological rebiopsy and liquid biopsy with the blood sampling, respectively. In the repeat rebiopsy, 23 (85%) and 4 (15%) of 27 underwent histological/cytological rebiopsy and liquid biopsy, respectively. The most frequently rebiopsied site was a pulmonary lesion (n = 24, 38.7%). Overall, 29 (46.0%) of 63 patients harbored the T790M mutation. Interestingly, a high detection rate of cancer cells did not necessarily indicate a high detection rate of the T790M mutation (p < 0.01). Among 34 patients with T790M-negative tumors confirmed on the first rebiopsy, 20 (58.8%) underwent repeat rebiopsies following interval therapy, revealing that seven (36.8%) had T790M-positive tumors. Osimertinib yielded median progression-free survival of 11.8 and 16.2 months in patients with the 790M mutation detected by the first rebiopsy and repeat rebiopsy, respectively. CONCLUSION: In our prospective cohort, the T790M mutation was detected in 46% of patients who underwent the first rebiopsy. Repeat rebiopsy may increase the ability to detect the T790M mutation positivity rate.

CD8+ T-cell Responses Are Boosted by Dual PD-1/VEGFR2 Blockade after EGFR Inhibition in Egfr-Mutant Lung Cancer.

Epidermal growth factor receptor (EGFR) is the most frequently mutated driver oncogene in nonsmoking-related, non-small cell lung cancer (NSCLC). EGFR-mutant NSCLC has a noninflamed tumor microenvironment (TME), with low infiltration by CD8+ T cells and, thus, immune-checkpoint inhibitors, such as antiprogrammed cell death-1 (anti-PD-1), have weak antitumor effects. Here, we showed that CD8+ T-cell responses were induced by an EGFR-tyrosine kinase inhibitor (TKI) in syngeneic Egfr-mutant NSCLC tumors, which was further pronounced by the sequential dual blockade of PD-1 and vascular endothelial growth factor receptor 2 (VEGFR2). However, the simultaneous triple blockade had no such effect. The PD-1/VEGFR2 dual blockade did not exert tumor-inhibitory effects without pretreatment with the EGFR-TKI, suggesting that the treatment schedule is crucial for the efficacy of the dual blockade therapy. Pretreatment with EGFR-TKI increased the CD8+ T-cell/regulatory T-cell (Treg) ratio, while also increasing the expression of immunosuppressive chemokines and chemokine receptors, as well as increasing the number of M2-like macrophages, in the TME. Discontinuing EGFR-TKI treatment reversed the transient increase of immunosuppressive factors in the TME. The subsequent PD-1/VEGFR2 inhibition maintained increased numbers of infiltrating CD8+ T cells and CD11c+ dendritic cells. Depletion of CD8+ T cells in vivo abolished tumor growth inhibition by EGFR-TKI alone and the sequential triple therapy, suggesting that EGFR inhibition is a prerequisite for the induction of CD8+ T-cell responses. Our findings could aid in developing an alternative immunotherapy strategy in patients with cancers that have driver mutations and a noninflamed TME.

Triple therapy with osimertinib, bevacizumab and cetuximab in EGFR-mutant lung cancer with HIF-1α/TGF-α expression.

Osimertinib, a third generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, is the standard treatment for patients with lung cancer harboring EGFR T790M; however, acquired resistance is inevitable due to genetic and epigenetic changes in cancer cells. In addition, a recent randomized clinical trial revealed that the combination of osimertinib and bevacizumab failed to exhibit superior progression-free survival compared with osimertinib alone. The present study aimed to investigate the effect of triple therapy with osimertinib, bevacizumab and cetuximab in xenograft tumors with different initial tumor volumes (conventional model, 200 mm3 and large model, 500 mm3). The results demonstrated that osimertinib significantly inhibited tumor growth in both the conventional and large models; however, maximum tumor regression was attenuated in the large model in which hypoxia-inducible factor-1α (HIF-1α) and transforming growth factor-α (TGF-α) expression levels increased. Although the combination of osimertinib and bevacizumab exerted a greater inhibitory effect on tumor growth compared with osimertinib in the conventional model, the effect of this combination therapy was attenuated in the large model. TGF-α attenuated sensitivity to osimertinib in vitro; however, this negative effect was counteracted by the combination of osimertinib and cetuximab, but not osimertinib and bevacizumab. In the large xenograft tumor model, the triple therapy induced the greatest inhibitory effect on tumor growth compared with osimertinib alone and its combination with bevacizumab. Clinical trials of the triple therapy are required for patients with lung cancer with EGFR mutations and HIF-1α/TGF-α.

SHP2 Inhibition Enhances the Effects of Tyrosine Kinase Inhibitors in Preclinical Models of Treatment-naïve ALK-, ROS1-, or EGFR-altered Non-small Cell Lung Cancer.

After molecular-targeted therapy, some cancer cells may remain that are resistant to therapies targeting oncogene alterations, such as those in the genes encoding the EGFR and anaplastic lymphoma kinase (ALK) as well as c-ros oncogene 1 (ROS1). The mechanisms underlying this type of resistance are unknown. In this article, we report the potential role of Src homology 2 domain-containing phosphatase 2 (SHP2) in the residual cells of ALK/ROS1/EGFR-altered non-small cell lung cancer (NSCLC). Molecular-targeted therapies failed to inhibit the ERK signaling pathway in the residual cells, whereas the SHP2 inhibitor SHP099 abolished their remaining ERK activity. SHP099 administered in combination with molecular-targeted therapy resulted in marked growth inhibition of cancer cells both in vitro and in vivo Thus, treatment combining an SHP2 inhibitor and a tyrosine kinase inhibitor may be a promising therapeutic strategy for oncogene-driven NSCLC.