An ultrasensitive method for quantitating circulating tumor DNA with broad patient coverage

Circulating tumor DNA (ctDNA) represents a promising biomarker for noninvasive assessment of cancer burden, but existing methods have insufficient sensitivity or patient coverage for broad clinical applicability. Here we introduce CAncer Personalized Profiling by deep Sequencing (CAPP-Seq), an economical and ultrasensitive method for quantifying ctDNA. We implemented CAPP-Seq for non-small cell lung cancer (NSCLC) with a design covering multiple classes of somatic alterations that identified mutations in >95% of tumors. We detected ctDNA in 100% of stage II–IV and 50% of stage I NSCLC patients, with 96% specificity for mutant allele fractions down to ~0.02%. Levels of ctDNA significantly correlated with tumor volume, distinguished between residual disease and treatment-related imaging changes, and provided earlier response assessment than radiographic approaches. Finally, we explored biopsy-free tumor screening and genotyping with CAPP-Seq. We envision that CAPP-Seq could be routinely applied clinically to detect and monitor diverse malignancies, thus facilitating personalized cancer therapy.

Early Detection of Molecular Residual Disease in Localized Lung Cancer by Circulating Tumor DNA Profiling

Identifying molecular residual disease (MRD) after treatment of localized lung cancer could facilitate early intervention and personalization of adjuvant therapies. Here, we apply cancer personalized profiling by deep sequencing (CAPP-seq) circulating tumor DNA (ctDNA) analysis to 255 samples from 40 patients treated with curative intent for stage I-III lung cancer and 54 healthy adults. In 94% of evaluable patients experiencing recurrence, ctDNA was detectable in the first posttreatment blood sample, indicating reliable identification of MRD. Posttreatment ctDNA detection preceded radiographic progression in 72% of patients by a median of 5.2 months, and 53% of patients harbored ctDNA mutation profiles associated with favorable responses to tyrosine kinase inhibitors or immune checkpoint blockade. Collectively, these results indicate that ctDNA MRD in patients with lung cancer can be accurately detected using CAPP-seq and may allow personalized adjuvant treatment while disease burden is lowest.Significance: This study shows that ctDNA analysis can robustly identify posttreatment MRD in patients with localized lung cancer, identifying residual/recurrent disease earlier than standard-of-care radiologic imaging, and thus could facilitate personalized adjuvant treatment at early time points when disease burden is lowest. Cancer Discov; 7(12); 1394-403. ©2017 AACR.See related commentary by Comino-Mendez and Turner, p. 1368This article is highlighted in the In This Issue feature, p. 1355.

Rociletinib in EGFR-mutated non-small-cell lung cancer

BACKGROUND

Non-small-cell lung cancer (NSCLC) with a mutation in the gene encoding epidermal growth factor receptor (EGFR) is sensitive to approved EGFR inhibitors, but resistance develops, mediated by the T790M EGFR mutation in most cases. Rociletinib (CO-1686) is an EGFR inhibitor active in preclinical models of EGFR-mutated NSCLC with or without T790M.

METHODS

In this phase 1-2 study, we administered rociletinib to patients with EGFR-mutated NSCLC who had disease progression during previous treatment with an existing EGFR inhibitor. In the expansion (phase 2) part of the study, patients with T790M-positive disease received rociletinib at a dose of 500 mg twice daily, 625 mg twice daily, or 750 mg twice daily. Key objectives were assessment of safety, side-effect profile, pharmacokinetics, and preliminary antitumor activity of rociletinib. Tumor biopsies to identify T790M were performed during screening. Treatment was administered in continuous 21-day cycles.

RESULTS

A total of 130 patients were enrolled. The first 57 patients to be enrolled received the free-base form of rociletinib (150 mg once daily to 900 mg twice daily). The remaining patients received the hydrogen bromide salt (HBr) form (500 mg twice daily to 1000 mg twice daily). A maximum tolerated dose (the highest dose associated with a rate of dose-limiting toxic effects of less than 33%) was not identified. The only common dose-limiting adverse event was hyperglycemia. In an efficacy analysis that included patients who received free-base rociletinib at a dose of 900 mg twice daily or the HBr form at any dose, the objective response rate among the 46 patients with T790M-positive disease who could be evaluated was 59% (95% confidence interval [CI], 45 to 73), and the rate among the 17 patients with T790M-negative disease who could be evaluated was 29% (95% CI, 8 to 51).

CONCLUSIONS

Rociletinib was active in patients with EGFR-mutated NSCLC associated with the T790M resistance mutation. (Funded by Clovis Oncology; ClinicalTrials.gov number, NCT01526928.).

Circulating tumour DNA profiling reveals heterogeneity of EGFR inhibitor resistance mechanisms in lung cancer patients

Circulating tumour DNA (ctDNA) analysis facilitates studies of tumour heterogeneity. Here we employ CAPP-Seq ctDNA analysis to study resistance mechanisms in 43 non-small cell lung cancer (NSCLC) patients treated with the third-generation epidermal growth factor receptor (EGFR) inhibitor rociletinib. We observe multiple resistance mechanisms in 46% of patients after treatment with first-line inhibitors, indicating frequent intra-patient heterogeneity. Rociletinib resistance recurrently involves MET, EGFR, PIK3CA, ERRB2, KRAS and RB1. We describe a novel EGFR L798I mutation and find that EGFR C797S, which arises in ∼33% of patients after osimertinib treatment, occurs in <3% after rociletinib. Increased MET copy number is the most frequent rociletinib resistance mechanism in this cohort and patients with multiple pre-existing mechanisms (T790M and MET) experience inferior responses. Similarly, rociletinib-resistant xenografts develop MET amplification that can be overcome with the MET inhibitor crizotinib. These results underscore the importance of tumour heterogeneity in NSCLC and the utility of ctDNA-based resistance mechanism assessment.

Integrating genomic features for non-invasive early lung cancer detection

Radiologic screening of high-risk adults reduces lung-cancer-related mortality1,2; however, a small minority of eligible individuals undergo such screening in the United States3,4. The availability of blood-based tests could increase screening uptake. Here we introduce improvements to cancer personalized profiling by deep sequencing (CAPP-Seq)5, a method for the analysis of circulating tumour DNA (ctDNA), to better facilitate screening applications. We show that, although levels are very low in early-stage lung cancers, ctDNA is present prior to treatment in most patients and its presence is strongly prognostic. We also find that the majority of somatic mutations in the cell-free DNA (cfDNA) of patients with lung cancer and of risk-matched controls reflect clonal haematopoiesis and are non-recurrent. Compared with tumour-derived mutations, clonal haematopoiesis mutations occur on longer cfDNA fragments and lack mutational signatures that are associated with tobacco smoking. Integrating these findings with other molecular features, we develop and prospectively validate a machine-learning method termed 'lung cancer likelihood in plasma' (Lung-CLiP), which can robustly discriminate early-stage lung cancer patients from risk-matched controls. This approach achieves performance similar to that of tumour-informed ctDNA detection and enables tuning of assay specificity in order to facilitate distinct clinical applications. Our findings establish the potential of cfDNA for lung cancer screening and highlight the importance of risk-matching cases and controls in cfDNA-based screening studies.

Heterogeneity Underlies the Emergence of EGFRT790 Wild-Type Clones Following Treatment of T790M-Positive Cancers with a Third-Generation EGFR Inhibitor

Rociletinib is a third-generation EGFR inhibitor active in lung cancers with T790M, the gatekeeper mutation underlying most first-generation EGFR drug resistance. We biopsied patients at rociletinib progression to explore resistance mechanisms. Among 12 patients with T790M-positive cancers at rociletinib initiation, six had T790-wild-type rociletinib-resistant biopsies. Two T790-wild-type cancers underwent small cell lung cancer transformation; three T790M-positive cancers acquired EGFR amplification. We documented T790-wild-type and T790M-positive clones coexisting within a single pre-rociletinib biopsy. The pretreatment fraction of T790M-positive cells affected response to rociletinib. Longitudinal circulating tumor DNA (ctDNA) analysis revealed an increase in plasma EGFR-activating mutation, and T790M heralded rociletinib resistance in some patients, whereas in others the activating mutation increased but T790M remained suppressed. Together, these findings demonstrate the role of tumor heterogeneity when therapies targeting a singular resistance mechanism are used. To further improve outcomes, combination regimens that also target T790-wild-type clones are required.

SIGNIFICANCE

This report documents that half of T790M-positive EGFR-mutant lung cancers treated with rociletinib are T790-wild-type upon progression, suggesting that T790-wild-type clones can emerge as the dominant source of resistance. We show that tumor heterogeneity has important clinical implications and that plasma ctDNA analyses can sometimes predict emerging resistance mechanisms.

EGFR-Mutant Adenocarcinomas That Transform to Small-Cell Lung Cancer and Other Neuroendocrine Carcinomas: Clinical Outcomes

PURPOSE

Approximately 3% to 10% of EGFR (epidermal growth factor receptor) -mutant non-small cell lung cancers (NSCLCs) undergo transformation to small-cell lung cancer (SCLC), but their clinical course is poorly characterized.

METHODS

We retrospectively identified patients with EGFR-mutant SCLC and other high-grade neuroendocrine carcinomas seen at our eight institutions. Demographics, disease features, and outcomes were analyzed.

RESULTS

We included 67 patients-38 women and 29 men; EGFR mutations included exon 19 deletion (69%), L858R (25%), and other (6%). At the initial lung cancer diagnosis, 58 patients had NSCLC and nine had de novo SCLC or mixed histology. All but these nine patients received one or more EGFR tyrosine kinase inhibitor before SCLC transformation. Median time to transformation was 17.8 months (95% CI, 14.3 to 26.2 months). After transformation, both platinum-etoposide and taxanes yielded high response rates, but none of 17 patients who received immunotherapy experienced a response. Median overall survival since diagnosis was 31.5 months (95% CI, 24.8 to 41.3 months), whereas median survival since the time of SCLC transformation was 10.9 months (95% CI, 8.0 to 13.7 months). Fifty-nine patients had tissue genotyping at first evidence of SCLC. All maintained their founder EGFR mutation, and 15 of 19 with prior EGFR T790M positivity were T790 wild-type at transformation. Other recurrent mutations included TP53, Rb1, and PIK3CA. Re-emergence of NSCLC clones was identified in some cases. CNS metastases were frequent after transformation.

CONCLUSION

There is a growing appreciation that EGFR-mutant NSCLCs can undergo SCLC transformation. We demonstrate that this occurs at an average of 17.8 months after diagnosis and cases are often characterized by Rb1, TP53, and PIK3CA mutations. Responses to platinum-etoposide and taxanes are frequent, but checkpoint inhibitors yielded no responses. Additional investigation is needed to better elucidate optimal strategies for this group.

Targeting RET in Patients With RET-Rearranged Lung Cancers: Results From the Global, Multicenter RET Registry

Purpose In addition to prospective trials for non-small-cell lung cancers (NSCLCs) that are driven by less common genomic alterations, registries provide complementary information on patient response to targeted therapies. Here, we present the results of an international registry of patients with RET-rearranged NSCLCs, providing the largest data set, to our knowledge, on outcomes of RET-directed therapy thus far. Methods A global, multicenter network of thoracic oncologists identified patients with pathologically confirmed NSCLC that harbored a RET rearrangement. Molecular profiling was performed locally by reverse transcriptase polymerase chain reaction, fluorescence in situ hybridization, or next-generation sequencing. Anonymized data-clinical, pathologic, and molecular features-were collected centrally and analyzed by an independent statistician. Best response to RET tyrosine kinase inhibition administered outside of a clinical trial was determined by RECIST v1.1. Results By April 2016, 165 patients with RET-rearranged NSCLC from 29 centers across Europe, Asia, and the United States were accrued. Median age was 61 years (range, 29 to 89 years). The majority of patients were never smokers (63%) with lung adenocarcinomas (98%) and advanced disease (91%). The most frequent rearrangement was KIF5B-RET (72%). Of those patients, 53 received one or more RET tyrosine kinase inhibitors in sequence: cabozantinib (21 patients), vandetanib (11 patients), sunitinib (10 patients), sorafenib (two patients), alectinib (two patients), lenvatinib (two patients), nintedanib (two patients), ponatinib (two patients), and regorafenib (one patient). The rate of any complete or partial response to cabozantinib, vandetanib, and sunitinib was 37%, 18%, and 22%, respectively. Further responses were observed with lenvantinib and nintedanib. Median progression-free survival was 2.3 months (95% CI, 1.6 to 5.0 months), and median overall survival was 6.8 months (95% CI, 3.9 to 14.3 months). Conclusion Available multikinase inhibitors had limited activity in patients with RET-rearranged NSCLC in this retrospective study. Further investigation of the biology of RET-rearranged lung cancers and identification of new targeted therapeutics will be required to improve outcomes for these patients.

A drug repositioning approach identifies tricyclic antidepressants as inhibitors of small cell lung cancer and other neuroendocrine tumors

Small cell lung cancer (SCLC) is an aggressive neuroendocrine subtype of lung cancer with high mortality. We used a systematic drug repositioning bioinformatics approach querying a large compendium of gene expression profiles to identify candidate U.S. Food and Drug Administration (FDA)-approved drugs to treat SCLC. We found that tricyclic antidepressants and related molecules potently induce apoptosis in both chemonaïve and chemoresistant SCLC cells in culture, in mouse and human SCLC tumors transplanted into immunocompromised mice, and in endogenous tumors from a mouse model for human SCLC. The candidate drugs activate stress pathways and induce cell death in SCLC cells, at least in part by disrupting autocrine survival signals involving neurotransmitters and their G protein-coupled receptors. The candidate drugs inhibit the growth of other neuroendocrine tumors, including pancreatic neuroendocrine tumors and Merkel cell carcinoma. These experiments identify novel targeted strategies that can be rapidly evaluated in patients with neuroendocrine tumors through the repurposing of approved drugs.

SIGNIFICANCE

Our work shows the power of bioinformatics-based drug approaches to rapidly repurpose FDA-approved drugs and identifies a novel class of molecules to treat patients with SCLC, a cancer for which no effective novel systemic treatments have been identified in several decades. In addition, our experiments highlight the importance of novel autocrine mechanisms in promoting the growth of neuroendocrine tumor cells.

Consequence of Abeta immunization on the vasculature of human Alzheimer's disease brain

A major feature of Alzheimer's disease is the accumulation of amyloid-beta peptide (Abeta) in the brain both in the form of plaques in the cerebral cortex and in blood vessel as cerebral amyloid angiopathy (CAA). Experimental models and human clinical trials have shown that accumulation of Abeta plaques can be reversed by immunotherapy. In this study, we hypothesized that Abeta in plaques is solubilized by antibodies generated by immunization and drains via the perivascular pathway, detectable as an increase in cerebrovascular Abeta. We have performed a follow up study of Alzheimer's disease patients immunized against Abeta42. Neuropathological examination was performed on nine patients who died between four months and five years after their first immunization. Immunostaining for Abeta40 and Abeta42 was quantified and compared with that in unimmunized Alzheimer's disease controls (n = 11). Overall, compared with these controls, the group of immunized patients had approximately 14 times as many blood vessels containing Abeta42 in the cerebral cortex (P<0.001) and seven times more in the leptomeninges (P = 0.013); among the affected blood vessels in the immunized cases, most of them had full thickness and full circumference involvement of the vessel wall in the cortex (P = 0.001), and in the leptomeninges (P = 0.015). There was also a significantly higher level of cerebrovascular Abeta40 in the immunized cases than in the unimmunized cases (cortex: P = 0.009 and leptomeninges: P = 0.002). In addition, the immunized patients showed a higher density of cortical microhaemorrhages and microvascular lesions than the unimmunized controls, though none had major CAA-related intracerebral haemorrhages. The changes in cerebral vascular Abeta load did not appear to substantially influence the structural proteins of the blood vessels. Unlike most of the immunized patients, two of the longest survivors, four to five years after first immunization, had virtually complete absence of both plaques and CAA, raising the possibility that, given time, Abeta is eventually cleared from the cerebral vasculature. The findings are consistent with the hypothesis that Abeta immunization results in solubilization of plaque Abeta42 which, at least in part, exits the brain via the perivascular pathway, causing a transient increase in the severity of CAA. The extent to which these vascular alterations following Abeta immunization in Alzheimer's disease are reflected in changes in cognitive function remains to be determined.

Noninvasive Early Identification of Therapeutic Benefit from Immune Checkpoint Inhibition

Although treatment of non-small cell lung cancer (NSCLC) with immune checkpoint inhibitors (ICIs) can produce remarkably durable responses, most patients develop early disease progression. Furthermore, initial response assessment by conventional imaging is often unable to identify which patients will achieve durable clinical benefit (DCB). Here, we demonstrate that pre-treatment circulating tumor DNA (ctDNA) and peripheral CD8 T cell levels are independently associated with DCB. We further show that ctDNA dynamics after a single infusion can aid in identification of patients who will achieve DCB. Integrating these determinants, we developed and validated an entirely noninvasive multiparameter assay (DIREct-On, Durable Immunotherapy Response Estimation by immune profiling and ctDNA-On-treatment) that robustly predicts which patients will achieve DCB with higher accuracy than any individual feature. Taken together, these results demonstrate that integrated ctDNA and circulating immune cell profiling can provide accurate, noninvasive, and early forecasting of ultimate outcomes for NSCLC patients receiving ICIs.

Increased complement biosynthesis by microglia and complement activation on neurons in Huntington's disease

In this study complement activation and biosynthesis have been analysed in the brains of Huntington's disease (HD) (n = 9) and normal (n = 3) individuals. In HD striatum, neurons, myelin and astrocytes were strongly stained with antibodies to C1q, C4, C3, iC3b-neoepitope and C9-neoepitope. In contrast, no staining for complement components was found in the normal striatum. Marked astrogliosis and microgliosis were observed in all HD caudate and the internal capsule samples but not in normal brain. RT-PCR analysis and in-situ hybridisation were carried out to determine whether complement was synthesised locally by activated glial cells. By RT-PCR, we found that complement activators of the classical pathway C1q C chain, C1r, C4, C3, as well as the complement regulators, C1 inhibitor, clusterin, MCP, DAF, CD59, were all expressed constitutively and at much higher level in HD brains compared to normal brain. Complement anaphylatoxin receptor mRNAs (C5a receptor and C3a receptor) were strongly expressed in HD caudate. In general, we found that the level of complement mRNA in normal control brains was from 2 to 5 fold lower compared to HD striatum. Using in-situ hybridisation, we confirmed that C3 mRNA and C9 mRNA were expressed by reactive microglia in HD internal capsule. We propose that complement produced locally by reactive microglia is activated on the membranes of neurons, contributing to neuronal necrosis but also to proinflammatory activities. Complement opsonins (iC3b) and anaphylatoxins (C3a, C5a) may be involved in the recruitment and stimulation of glial cells and phagocytes bearing specific complement receptors.

Circulating Tumor DNA Dynamics Predict Benefit from Consolidation Immunotherapy in Locally Advanced Non-Small Cell Lung Cancer

Circulating tumor DNA (ctDNA) molecular residual disease (MRD) following curative-intent treatment strongly predicts recurrence in multiple tumor types, but whether further treatment can improve outcomes in patients with MRD remains unclear. We applied CAPP-Seq ctDNA analysis to 218 samples from 65 patients receiving chemoradiation therapy (CRT) for locally advanced NSCLC, including 28 patients receiving consolidation immune checkpoint inhibition (CICI). Patients with undetectable ctDNA after CRT had excellent outcomes whether or not they received CICI. Among such patients, one died from CICI-related pneumonitis, highlighting the potential utility of only treating patients with MRD. In contrast, patients with MRD after CRT who received CICI had significantly better outcomes than patients who did not receive CICI. Furthermore, the ctDNA response pattern early during CICI identified patients responding to consolidation therapy. Our results suggest that CICI improves outcomes for NSCLC patients with MRD and that ctDNA analysis may facilitate personalization of consolidation therapy.

Aberrant interactions of transcriptional repressor proteins with the Huntington's disease gene product, huntingtin

We detected an interaction of the N-terminus of huntingtin (htt171) with the C-terminal region of the nuclear receptor co-repressor (N-CoR) using the yeast two-hybrid system. This interaction was repeat length dependent and specific to htt171; the co-repressor did not interact with the repeat carrying a section of atrophin 1 nor with the androgen receptor or polyglutamine alone. The interaction was confirmed using His-tagged Escherichia coli -expressed C-terminal human and rat co-repressor protein which pulled full-length huntingtin out of homogenized rat brain and in pull-down assays. The N-CoR represses transcription from sequence-specific ligand-activated receptors such as the retinoid X-thyroid hormone receptor dimers and other nuclear receptors including Mad-Max receptor dimers. The mechanism of this repression appears to be through the formation of a complex of repressor proteins including the N-CoR, mSin3 and histone deacetylases. We have used N-CoR and mSin3A antibodies in immunohistochemical studies and find that in Huntington's disease (HD) cortex and caudate, the cellular localization of these proteins is exclusively cytoplasmic whilst in control brain they are localized in the nucleus as well as the cytoplasm; mSin3A immunoreactivity also occurred in a subset of huntingtin positive intranuclear inclusions. The relocalization of repressor proteins in HD brain may alter transcription and be involved in the pathology of the disease.

The Society for Immunotherapy of Cancer consensus statement on immunotherapy for the treatment of non-small cell lung cancer (NSCLC)

Lung cancer is the leading cause of cancer-related mortality worldwide, with non-small cell lung cancer (NSCLC) accounting for over 85% of all cases. Until recently, chemotherapy – characterized by some benefit but only rare durable responses – was the only treatment option for patients with NSCLC whose tumors lacked targetable mutations. By contrast, immune checkpoint inhibitors have demonstrated distinctly durable responses and represent the advent of a new treatment approach for patients with NSCLC. Three immune checkpoint inhibitors, pembrolizumab, nivolumab and atezolizumab, are now approved for use in first- and/or second-line settings for selected patients with advanced NSCLC, with promising benefit also seen in patients with stage III NSCLC. Additionally, durvalumab following chemoradiation has been approved for use in patients with locally advanced disease. Due to the distinct features of cancer immunotherapy, and rapid progress in the field, clinical guidance is needed on the use of these agents, including appropriate patient selection, sequencing of therapies, response monitoring, adverse event management, and biomarker testing. The Society for Immunotherapy of Cancer (SITC) convened an expert Task Force charged with developing consensus recommendations on these key issues. Following a systematic process as outlined by the National Academy of Medicine, a literature search and panel voting were used to rate the strength of evidence for each recommendation. This consensus statement provides evidence-based recommendations to help clinicians integrate immune checkpoint inhibitors into the treatment plan for patients with NSCLC. This guidance will be updated following relevant advances in the field.

Activity and Safety of Mobocertinib (TAK-788) in Previously Treated Non-Small Cell Lung Cancer with EGFR Exon 20 Insertion Mutations from a Phase I/II Trial

Mobocertinib, an oral epidermal growth factor receptor (EGFR) inhibitor targeting EGFR gene mutations, including exon 20 insertions (EGFRex20ins), in non-small cell lung cancer, was evaluated in a phase I/II dose-escalation/expansion trial (ClinicalTrials.gov NCT02716116). Dose escalation identified 160 mg/d as the recommended phase 2 dose and maximum tolerated dose. Among 136 patients treated with 160 mg/d, the most common any-grade treatment-related adverse events (TRAE; >25%) were diarrhea (83%), nausea (43%), rash (33%), and vomiting (26%), with diarrhea (21%) the only grade ≥3 TRAE >5%. Among 28 EGFRex20ins patients treated at 160 mg/d, the investigator-assessed confirmed response rate was 43% (12/28; 95% confidence interval, 24%-63%) with median duration of response of 14 months (5.0-not reached) and median progression-free survival of 7.3 months (4.4-15.6). Mobocertinib demonstrated antitumor activity in patients with diverse EGFRex20ins variants with a safety profile consistent with other EGFR inhibitors. SIGNIFICANCE: No oral EGFR-targeted therapies are currently approved for patients with EGFRex20ins NSCLC. Mobocertinib demonstrated antitumor activity with manageable toxicity in patients with advanced EGFRex20ins NSCLC in this study, supporting additional development of mobocertinib in this patient population.See related commentary by Pacheco, p. 1617.This article is highlighted in the In This Issue feature, p. 1601.

SELECT: A Phase II Trial of Adjuvant Erlotinib in Patients With Resected Epidermal Growth Factor Receptor-Mutant Non-Small-Cell Lung Cancer

PURPOSE

Given the pivotal role of epidermal growth factor receptor (EGFR) inhibitors in advanced EGFR-mutant non-small-cell lung cancer (NSCLC), we tested adjuvant erlotinib in patients with EGFR-mutant early-stage NSCLC.

MATERIALS AND METHODS

In this open-label phase II trial, patients with resected stage IA to IIIA (7^th edition of the American Joint Committee on Cancer staging system) EGFR-mutant NSCLC were treated with erlotinib 150 mg per day for 2 years after standard adjuvant chemotherapy with or without radiotherapy. The study was designed for 100 patients and powered to demonstrate a primary end point of 2-year disease-free survival (DFS) greater than 85%, improving on historic data of 76%.

RESULTS

Patients (N = 100) were enrolled at seven sites from January 2008 to May 2012; 13% had stage IA disease, 32% had stage IB disease, 11% had stage IIA disease, 16% had stage IIB disease, and 28% had stage IIIA disease. Toxicities were typical of erlotinib; there were no grade 4 or 5 adverse events. Forty percent of patients required erlotinib dose reduction to 100 mg per day and 16% to 50 mg per day. The intended 2-year course was achieved in 69% of patients. The median follow-up was 5.2 years, and 2-year DFS was 88% (96% stage I, 78% stage II, 91% stage III). Median DFS and overall survival have not been reached; 5-year DFS was 56% (95% CI, 45% to 66%), 5-year overall survival was 86% (95% CI, 77% to 92%). Disease recurred in 40 patients, with only four recurrences during erlotinib treatment. The median time to recurrence was 25 months after stopping erlotinib. Of patients with recurrence who underwent rebiopsy (n = 24; 60%), only one had T790M mutation detected. The majority of patients with recurrence were retreated with erlotinib (n = 26; 65%) for a median duration of 13 months.

CONCLUSION

Patients with EGFR-mutant NSCLC treated with adjuvant erlotinib had an improved 2-year DFS compared with historic genotype-matched controls. Recurrences were rare for patients receiving adjuvant erlotinib, and patients rechallenged with erlotinib after recurrence experienced durable benefit.

Ensartinib (X-396) in ALK-Positive Non-Small Cell Lung Cancer: Results from a First-in-Human Phase I/II, Multicenter Study

Purpose: Evaluate safety and determine the recommended phase II dose (RP2D) of ensartinib (X-396), a potent anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitor (TKI), and evaluate preliminary pharmacokinetics and antitumor activity in a first-in-human, phase I/II clinical trial primarily in patients with non-small cell lung cancer (NSCLC).Patients and Methods: In dose escalation, ensartinib was administered at doses of 25 to 250 mg once daily in patients with advanced solid tumors; in dose expansion, patients with advanced ALK-positive NSCLC were administered 225 mg once daily. Patients who had received prior ALK TKI(s) and patients with brain metastases were eligible.Results: Thirty-seven patients enrolled in dose escalation, and 60 enrolled in dose expansion. The most common treatment-related toxicities were rash (56%), nausea (36%), pruritus (28%), vomiting (26%), and fatigue (22%); 23% of patients experienced a treatment-related grade 3 to 4 toxicity (primarily rash and pruritus). The maximum tolerated dose was not reached, but the RP2D was chosen as 225 mg based on the frequency of rash observed at 250 mg without improvement in activity. Among the ALK-positive efficacy evaluable patients treated at ≥200 mg, the response rate (RR) was 60%, and median progression-free survival (PFS) was 9.2 months. RR in ALK TKI-naïve patients was 80%, and median PFS was 26.2 months. In patients with prior crizotinib only, the RR was 69% and median PFS was 9.0 months. Responses were also observed in the central nervous system, with an intracranial RR of 64%.Conclusions: Ensartinib was active and generally well tolerated in patients with ALK-positive NSCLC. Clin Cancer Res; 24(12); 2771-9. ©2018 AACR.

Glycogen synthase kinase-3 inhibits the DNA binding activity of NFATc

The NFAT family of transcription factors is required for the expression of numerous immunologically important genes and plays a pivotal role in both the initiation and coordination of the immune response. NFAT family members appear to be regulated primarily at the level of their subcellular localization. Here we show that NFATc is additionally regulated at the level of its DNA binding activity. Using gel mobility shift assays, we demonstrate that the intrinsic DNA binding activity of NFATc is negatively regulated by phosphorylation. We found that activation of calcineurin activity in cells and dephosphorylation of NFATc in vitro enhanced NFATc DNA binding activity, whereas phosphorylation of NFATc in vitro inhibited its ability to bind DNA. Through the analysis of NFATc mutants, we identified the conserved Ser-Pro repeat motifs as critical quantitative determinants of NFATc DNA binding activity. In addition, we provide several lines of evidence to suggest that the phosphorylation of the Ser-Pro repeats by glycogen synthase kinase-3 inhibits the ability of NFATc to bind DNA. Taken together, these studies afford new insights into the regulation of NFATc and underscore the potential role of glycogen synthase kinase-3 in the regulation of NFAT-dependent gene expression.

Isolation and mutational analysis of circulating tumor cells from lung cancer patients with magnetic sifters and biochips

Detection and characterization of circulating tumor cells (CTCs) may reveal insights into the diagnosis and treatment of malignant disease. Technologies for isolating CTCs developed thus far suffer from one or more limitations, such as low throughput, inability to release captured cells, and reliance on expensive instrumentation for enrichment or subsequent characterization. We report a continuing development of a magnetic separation device, the magnetic sifter, which is a miniature microfluidic chip with a dense array of magnetic pores. It offers high efficiency capture of tumor cells, labeled with magnetic nanoparticles, from whole blood with high throughput and efficient release of captured cells. For subsequent characterization of CTCs, an assay, using a protein chip with giant magnetoresistive nanosensors, has been implemented for mutational analysis of CTCs enriched with the magnetic sifter. The use of these magnetic technologies, which are separate devices, may lead the way to routine preparation and characterization of "liquid biopsies" from cancer patients.

Erlotinib, cabozantinib, or erlotinib plus cabozantinib as second-line or third-line treatment of patients with EGFR wild-type advanced non-small-cell lung cancer (ECOG-ACRIN 1512): a randomised, controlled, open-label, multicentre, phase 2 trial

BACKGROUND

Erlotinib is approved for the treatment of all patients with advanced non-small-cell lung cancer (NSCLC), but is most active in the treatment of EGFR mutant NSCLC. Cabozantinib, a small molecule tyrosine kinase inhibitor, targets MET, VEGFR, RET, ROS1, and AXL, which are implicated in lung cancer tumorigenesis. We compared the efficacy of cabozantinib alone or in combination with erlotinib versus erlotinib alone in patients with EGFR wild-type NSCLC.

METHODS

This three group, randomised, controlled, open-label, multicentre, phase 2 trial was done in 37 academic and community oncology practices in the USA. Patients were eligible if they had received one or two previous treatments for advanced non-squamous, EGFR wild-type, NSCLC. Patients were stratified by performance status and line of therapy, and randomly assigned using permuted blocks within strata to receive open-label oral daily dosing of erlotinib (150 mg), cabozantinib (60 mg), or erlotinib (150 mg) and cabozantinib (40 mg). Imaging was done every 8 weeks. At the time of radiographic progression, there was optional crossover for patients in either single-drug group to receive combination treatment. The primary endpoint was to compare progression-free survival in patients given erlotinib alone versus cabozantinib alone, and in patients given erlotinib alone versus the combination of erlotinib plus cabozantinib. We assessed the primary endpoint in the per-protocol population, which was defined as all patients who were eligible, randomly assigned, and received at least one dose of treatment. The safety analysis population included all patients who received study treatment irrespective of eligibility. This trial is registered with ClinicalTrials.gov, number NCT01708954.

FINDINGS

Between Feb 7, 2013, and July 1, 2014, we enrolled and randomly assigned 42 patients to erlotinib treatment, 40 patients to cabozantinib treatment, and 43 patients to erlotinib plus cabozantinib treatment, of whom 111 (89%) in total were included in the primary analysis (erlotinib [n=38], cabozantinib [n=38], erlotinib plus cabozantinib [n=35]). Compared with erlotinib alone (median 1·8 months [95% CI 1·7-2·2]), progression-free survival was significantly improved in the cabozantinib group (4·3 months [3·6-7·4]; hazard ratio [HR] 0·39, 80% CI 0·27-0·55; one-sided p=0·0003) and in the erlotinib plus cabozantinib group (4·7 months [2·4-7·4]; HR 0·37, 0·25-0·53; one-sided p=0·0003). Among participants included in the safety analysis of the erlotinib (n=40), cabozantinib (n=40), and erlotinib plus cabozantinib (n=39) groups, the most common grade 3 or 4 adverse events were diarrhoea (three [8%] cases in the erlotinib group vs three [8%] in the cabozantinib group vs 11 [28%] in the erlotinib plus cabozantinib group), hypertension (none vs ten [25%] vs one [3%]), fatigue (five [13%] vs six [15%] vs six [15%]), oral mucositis (none vs four [10%] vs one [3%]), and thromboembolic event (none vs three [8%] vs two [5%]). One death due to respiratory failure occurred in the cabozantinib group, deemed possibly related to either drug, and one death due to pneumonitis occurred in the erlotinib plus cabozantinib group, deemed related to either drug or the combination.

INTERPRETATION

Despite its small sample size, this trial showed that, in patients with EGFR wild-type NSCLC, cabozantinib alone or combined with erlotinib has clinically meaningful, superior efficacy to that of erlotinib alone, with additional toxicity that was generally manageable. Cabozantinib-based regimens are promising for further investigation in this patient population.

FUNDING

ECOG-ACRIN Cancer Research Group, National Cancer Institute of the National Institutes of Health.

A constitutively active NFATc1 mutant induces a transformed phenotype in 3T3-L1 fibroblasts

The calcineurin/nuclear factor of activated T cells (NFAT) signaling pathway is best known for its role in T lymphocyte activation. However, it has become increasingly apparent that this signaling pathway is also involved in the regulation of cell growth and development in a wide variety of different tissues and cell types. Here we have investigated the effects of sustained NFATc1 signaling on the growth and differentiation of the murine 3T3-L1 preadipocyte cell line. Remarkably, we find that expression of a constitutively active NFATc1 mutant (caNFATc1) in these immortalized cells inhibits their differentiation into mature adipocytes and causes them to adopt a transformed cell phenotype, including loss of contact-mediated growth inhibition, reduced serum growth requirements, protection from growth factor withdrawal-induced apoptosis, and formation of colonies in semisolid media. Furthermore, we find that caNFATc1-expressing cells acquire growth factor autonomy and are able to proliferate even in the complete absence of serum. We provide evidence that this growth factor independence is caused by the NFATc1-dependent production of a soluble heat-labile autocrine factor that is capable of promoting the growth and survival of wild type 3T3-L1 cells as well as potently inhibiting their differentiation into mature adipocytes. Finally, we demonstrate that cells expressing caNFATc1 form tumors in nude mice. Taken together, these results indicate that deregulated NFATc1 activity is able to induce the immortalized 3T3-L1 preadipocyte cell line to acquire the well established hallmarks of cellular transformation and thereby provide direct evidence for the oncogenic potential of the NFATc1 transcription factor.

Spontaneous classical pathway activation and deficiency of membrane regulators render human neurons susceptible to complement lysis

This study investigated the capacity of neurons and astrocytes to spontaneously activate the complement system and control activation by expressing complement regulators. Human fetal neurons spontaneously activated complement through the classical pathway in normal and immunoglobulin-deficient serum and C1q binding was noted on neurons but not on astrocytes. A strong staining for C4, C3b, iC3b neoepitope and C9 neoepitope was also found on neurons. More than 40% of human fetal neurons were lysed when exposed to normal human serum in the presence of a CD59-blocking antibody, whereas astrocytes were unaffected. Significant reduction in neuronal cell lysis was observed after the addition of soluble complement receptor 1 at 10 microg/ml. Fetal neurons were stained for CD59 and CD46 and were negative for CD55 and CD35. In contrast, fetal astrocytes were strongly stained for CD59, CD46, CD55, and were negative for CD35. This study demonstrates that human fetal neurons activate spontaneously the classical pathway of complement in an antibody-independent manner to assemble the cytolytic membrane attack complex on their membranes, whereas astrocytes are unaffected. One reason for the susceptibility of neurons to complement-mediated damage in vivo may reside in their poor capacity to control complement activation.

Impact of KRAS mutation subtype and concurrent pathogenic mutations on non-small cell lung cancer outcomes

OBJECTIVES

Concurrent genetic mutations are prevalent in KRAS-mutant non-small cell lung cancer (NSCLC) and may differentially influence patient outcomes. We sought to characterize the effects of KRAS mutation subtypes and concurrent pathogenic mutations on overall survival (OS) and PD-L1 expression, a predictive biomarker for anti-PD-1/PD-L1 immunotherapy.

MATERIALS AND METHODS

We retrospectively identified patients with KRAS-mutant NSCLC at a single institution and abstracted clinical, molecular, and pathologic data from electronic health records. Cox regression and multinomial logistic regression were used to determine how KRAS mutation subtypes and concurrent pathogenic mutations are associated with OS and tumor PD-L1 expression, respectively.

RESULTS

A total 186 patients were included. Common KRAS mutation subtypes included G12C (35%) and G12D (17%). Concurrent pathogenic mutations were identified in TP53 (39%), STK11 (12%), KEAP1 (8%), and PIK3CA (4%). On multivariable analysis, KRAS G12D mutations were significantly associated with poor OS (hazard ratio [HR] 2.43, 95% confidence interval [CI] 1.15-5.16; P = 0.021), as were STK11 co-mutations (HR 2.95, 95% CI 1.27-6.88; P = 0.012). Compared to no (<1%) PD-L1 expression, KRAS G12C mutations were significantly associated with positive yet low (1-49%) PD-L1 expression (odds ratio [OR] 4.94, 95% CI 1.07-22.85; P = 0.041), and TP53 co-mutations with high (≥50%) PD-L1 expression (OR 6.36, 95% CI 1.84-22.02; P = 0.004).

CONCLUSION

KRAS G12D and STK11 mutations confer poor prognoses for patients with KRAS-mutant NSCLC. KRAS G12C and TP53 mutations correlate with a biomarker that predicts benefit from immunotherapy. Concurrent mutations may represent distinct subsets of KRAS-mutant NSCLC; further investigation is warranted to elucidate their role in guiding treatment.

Innate immunity and protective neuroinflammation: new emphasis on the role of neuroimmune regulatory proteins

Brain inflammation due to infection, hemorrhage, and aging is associated with activation of the local innate immune system as expressed by infiltrating cells, resident glial cells, and neurons. The innate immune response relies on the detection of "nonself" and "danger-self" ligands behaving as "eat me signals" by a plethora of pattern recognition receptors (PRRs) expressed by professional and amateur phagocytes to promote the clearance of pathogens, toxic cell debris (amyloid fibrils, aggregated synucleins, prions), and apoptotic cells accumulating within the brain parenchyma and the cerebrospinal fluid (CSF). These PRRs (e.g., complement, TLR, CD14, scavenger receptors) are highly conserved between vertebrates and invertebrates and may represent the most ancestral innate scavenging system involved in tissue homeostasis. However, in some diseases, these protective mechanisms lead to neurodegeneration on the ground that several innate immune molecules have neurocytotoxic activities. The response is a "double-edged sword" representing a fine balance between protective and detrimental effects. Several key regulatory mechanisms have now been evidenced in the control of CNS innate immunity, and these could be harnessed to explore novel therapeutic avenues. We will herein provide new emphasis on the role of neuroimmune regulatory proteins (NIRegs), such as CD95L, TNF, CD200, CD47, sialic acids, CD55, CD46, fH, C3a, HMGB1, which are involved in silencing innate immunity at the cellular and molecular levels and suppression of inflammation. For instance, NIRegs may play an important role in controlling lymphocyte/macrophage/microglia hyperinflammatory responses, while sparing host defense and repair mechanisms. Moreover, NIRegs have direct beneficial effects on neurogenesis and contributing to brain tissue remodeling.