monitoring-pd-1-blocking-antibodies-bound-to-t-cells-derived-from

Monitoring PD-1-Blocking Antibodies Bound to T Cells Derived from a Drop of Peripheral Blood

Immune checkpoint inhibitors, including PD-1&#8211;blocking antibodies, have significantly improved treatment outcomes in various types of cancer. The ...

Osaka University Graduate School of Medicine

We present two patients with leptomeningeal metastases (LM) from lung adenocarcinoma that progressed or newly developed, respectively, during gefitinib therapy which had exhibited substantial antitumor effects on widespread lesions. In both cases, a switch to erlotinib therapy brought about long-lasting dramatic symptomatic improvement and markedly prolonged survival. The first patient is a 46-year-old female who presented with progressive headache and vomiting. Multiple pulmonary, hepatic and bone metastases immediately shrank in response to gefitinib. However, 1 month after completion of concurrent whole brain radiation, dizziness and urinary retention newly emerged, worsening the symptoms observed at presentation. Magnetic resonance imaging (MRI) demonstrated enlargement of ventricles and new gadolinium (Gd)-enhanced disseminated nodules on the surface of the cerebral cortex, suggesting the existence of uncontrollable LM. Sequential erlotinib therapy resulted in symptomatic improvement with a finding of regression of Gd-enhancement on MRI. The beneficial effect lasted for 10 months, though a follow-up brain MRI showed further enlarged ventricles. She finally died due to LM after surviving for 11 months under erlotinib treatment. The other patient is a 55-year-old female in whom headache and vomiting occurred while gefitinib therapy had maintained shrinkage of all pre-existing tumors in the thorax and bones. Brain MRI strongly suggested occurrence of LM with a finding of Gd-enhanced sulci. A switch to erlotinib therapy relieved the symptoms with disappearance of Gd-enhancement. However, the symptoms recurred with a finding of further enlargement of ventricles on brain MRI after 11 months. Finally, she died due to LM after surviving for 12 months under erlotinib treatment.

Two cases of leptomeningeal metastases from lung adenocarcinoma which progressed during gefitinib therapy but responded to erlotinib.

Proinflammatory cytokine interleukin-17A (IL-17A) is overexpressed in a subset of patients with lung cancer. We hypothesized that IL-17A promotes a protumorigenic inflammatory phenotype and inhibits antitumor immune responses.

Interleukin-17A Promotes Lung Tumor Progression through Neutrophil Attraction to Tumor Sites and Mediating Resistance to PD-1 Blockade.

Overcoming chemoresistance is essential for achieving better prognoses in SCLC. Previously, we reported that HER2 is upregulated when HER2-positive SCLC cells acquire chemoresistance. HER2-upregulated cisplatin- or etoposide-resistant SCLC cells were sensitive to trastuzumab-mediated ADCC. However, irinotecan-resistant SCLC cells, such as SBC-3/SN-38, were refractory to trastuzumab despite high HER2 expression. To address this issue, we examined the antitumor efficacy of trastuzumab emtansine (T-DM1) on trastuzumab-resistant HER2-positive SCLC. Treatment with T-DM1 significantly suppressed the growth of SBC-3/SN-38 xenografts in mice compared with trastuzumab (P < 0.05). Histological analysis of xenografts was performed to evaluate the therapeutic effect on apoptosis, proliferation and tumor vasculature. T-DM1 monotherapy induced apoptosis in SBC-3/SN-38 xenografts to a greater extent than trastuzumab monotherapy with the apoptotic index of 3.71 ± 1.56% vs. 0.60 ± 0.32% (P < 0.05), and also inhibited the proliferation of tumor cells compared with trastuzumab with the proliferative index of 74.30 ± 5.54% vs. 80.12 ± 4.81% (P < 0.05). On the other hand, no significant difference in micro vessel density was observed between the treatment groups. In vivo imaging using fluorescence-labeled T-DM1 showed that intravenously administered T-DM1 was rapidly delivered to xenografts and continued to accumulate for several days in a HER2-selective fashion. From these findings, delivery of the cytotoxic agent DM1 into cells via HER2-mediated internalization is expected to exert antitumor effect in such ADCC-lacking SCLC cells. Collectively, T-DM1 will be a promising option for overcoming trastuzumab-resistance in HER2-upregulated SCLC.

Trastuzumab emtansine suppresses the growth of HER2-positive small-cell lung cancer in preclinical models.

The PD-1-blocking antibody nivolumab persists in patients several weeks after the last infusion. However, no study has systematically evaluated the maximum duration that the antibody persists on T cells or the association between this duration and residual therapeutic efficacy or potential adverse events.

Clinical implications of monitoring nivolumab immunokinetics in non-small cell lung cancer patients.

Although responses to EGFR tyrosine kinase inhibitors (EGFR-TKIs) are initially positive, 30%-40% of patients with EGFR-mutant tumors do not respond well to EGFR-TKIs, and most lung cancer patients harboring EGFR mutations experience relapse with resistance. Therefore, it is necessary to identify not only the mechanisms underlying EGFR-TKI resistance, but also potentially novel therapeutic targets and/or predictive biomarkers for EGFR-mutant lung adenocarcinoma. We found that the GPI-anchored protein semaphorin 7A (SEMA7A) is highly induced by the EGFR pathway, via mTOR signaling, and that expression levels of SEMA7A in human lung adenocarcinoma specimens were correlated with mTOR activation. Investigations using cell culture and animal models demonstrated that loss or overexpression of SEMA7A made cells less or more resistant to EGFR-TKIs, respectively. The resistance was due to the inhibition of apoptosis by aberrant activation of ERK. The ERK signal was suppressed by knockdown of integrin β1 (ITGB1). Furthermore, in patients with EGFR mutant tumors, higher SEMA7A expression in clinical samples predicted poorer response to EGFR-TKI treatment. Collectively, these data show that the SEMA7A-ITGB1 axis plays pivotal roles in EGFR-TKI resistance mediated by ERK activation and apoptosis inhibition. Moreover, our results reveal the potential utility of SEMA7A not only as a predictive biomarker, but also as a potentially novel therapeutic target in EGFR-mutant lung adenocarcinoma.

Semaphorin 7A promotes EGFR-TKI resistance in EGFR mutant lung adenocarcinoma cells.

We report a case of a 65-year-old woman with stage IV lung adenocarcinoma who experienced Stevens-Johnson syndrome (SJS) during afatinib therapy. The patient received afatinib as the first-line therapy after the confirmation of harboring an exon 19 deletion mutation in the epidermal growth factor receptor (EGFR) gene. The patient presented with multiple erythematous papules mainly on the body trunk and thigh 32 days after afatinib administration. Subsequently, diffuse erosions of oral mucosa and purpuric macules with flat atypical targets emerged. Skin biopsy specimen showed the histology compatible with epidermal necrosis and the patient was diagnosed as having SJS. The symptoms of SJS were recovered by systemic steroid and immunoglobulin treatment. Gefitinib was administered as the third-line therapy after the second-line therapy with carboplatin plus pemetrexed had failed. Tumor shrinkage was obtained shortly and has been maintained without the recurrence of SJS. Rechallenge of tyrosine kinase inhibitor by gefitinib could be an alternative treatment option in patients who experienced SJS by afatinib.

Successful treatment with gefitinib after Stevens-Johnson syndrome associated with afatinib therapy in a patient with adenocarcinoma of the lung.

Recent clinical trials have demonstrated that anti-PD-1 blocking antibodies showed remarkable clinical efficacy in a subset of non-small cell lung cancer (NSCLC) patients. Clinical trials usually exclude patients with renal dysfunction who are receiving hemodialysis (HD). Therefore, it is unclear whether these patients can be safely and effectively treated with pembrolizumab. Here, we present a non-small cell lung cancer patient on HD who achieved complete remission after one dose of pembrolizumab without severe adverse events. We assessed pembrolizumab binding to peripheral blood T cells in this patient using a method that we recently developed. This is the first report to visualize pembrolizumab binding to T cells in a patient on HD during and after pembrolizumab treatment. The pharmacokinetics of pembrolizumab in this case were similar to those in patients with normal renal function, suggesting that severe renal dysfunction has little influence on the metabolism of pembrolizumab, and is not a contraindication for anti-PD-1 treatment. Immune checkpoint inhibitors, including pembrolizumab, may be a vital therapeutic option for lung cancer patients on HD.

Akio Osa

Department of Respiratory Medicine and Clinical Immunology

Osaka University Graduate School of Medicine

Monitoring PD-1-Blocking Antibodies Bound to T Cells Derived from a Drop of Peripheral Blood