Toxicity with small molecule and immunotherapy combinations in non-small cell lung cancer

Treatment stratification in stage IV NSCLC is guided by identification of oncogene driver mutations. Actionable mutations with current licenced therapeutic agents include epidermal growth factor receptor (EGFR), rearrangements of anaplastic lymphoma kinase (ALK), ROS-1 and BRAF V600. Alongside progress with small molecule therapy, developments in immune checkpoint inhibitors (CPIs) have transformed the landscape of stage III and stage IV NSCLC. The success of CPIs has led to evaluation with small molecule therapy in both concurrent and sequential settings. In this review we summarise recent results of combination CPIs and tyrosine kinase inhibitors (TKIs) in stage IV NSCLC, detailing significant toxicity and its potential mechanisms with both concurrent and sequential approaches. As more therapeutic targets are being discovered it is becoming increasingly important for clinicians to correctly sequence therapy for delivery of safe and effective treatment. In addition to stage IV disease we suggest that comprehensive molecular profiling of key NSCLC drivers, particularly in stage III disease, will help to inform optimal treatment sequencing and minimise potential toxicity.

Germline and sporadic cancers driven by the RAS pathway: parallels and contrasts

Somatic mutations in RAS and related pathway genes such as NF1 have been strongly implicated in the development of cancer while also being implicated in a diverse group of developmental disorders named the 'RASopathies', including neurofibromatosis type 1 (NF1), Noonan syndrome (NS), Noonan syndrome with multiple lentigines (NSML), Costello syndrome (CS), cardiofaciocutaneous syndrome (CFC), and capillary malformation-arteriovenous syndrome (CM-AVM). It remains unclear why (i) there is little overlap in mutational subtype between Ras-driven malignancies associated with sporadic disease and those associated with the RASopathy syndromes, and (ii) RASopathy-associated cancers are usually of different histological origin to those seen with sporadic mutations of the same genes. For instance, germline variants in KRAS and NRAS are rarely found at codons 12, 13 or 61, the most common sites for somatic mutations in sporadic cancers. An exception is CS, where germline variants in codons 12 and 13 of HRAS occur relatively frequently. Given recent renewed drug interest following early clinical success of RAS G12C and farnesyl transferase inhibitors, an improved understanding of this relationship could help guide targeted therapies for both sporadic and germline cancers associated with the Ras pathway.

EPAC-lung: pooled analysis of circulating tumour cells in advanced non-small cell lung cancer

INTRODUCTION

We assessed the clinical validity of circulating tumour cell (CTC) quantification for prognostication of patients with advanced non-small cell lung cancer (NSCLC) by undertaking a pooled analysis of individual patient data.

METHODS

Nine European NSCLC CTC centres were asked to provide reported/unreported pseudo-anonymised data for patients with advanced NSCLC who participated in CellSearch CTC studies from January 2003 to March 2017. We used Cox regression models, stratified by centres, to establish the association between CTC count and survival. We assessed the added value of CTCs to prognostic clinicopathological models using likelihood ratio (LR) statistics and c-indices.

RESULTS

Seven out of nine eligible centres provided data for 550 patients with prognostic information for overall survival. CTC counts of ≥2 and ≥ 5 per 7·5 mL were associated with reduced progression-free survival (≥2 CTCs: hazard ratio [HR] = 1.72, p < 0·001; ≥5 CTCs: HR = 2.21, p < 0·001) and overall survival (≥2 CTCs: HR = 2·18, p < 0·001; ≥5 CTCs: HR = 2·75, p < 0·001), respectively. Survival prediction was significantly improved by addition of baseline CTC count to LR clinicopathological models (log-transformed CTCs p < 0·001; ≥2 CTCs p < 0·001; ≥5 CTCs p ≤ 0·001 for both survival end-points), whereas moderate improvements were observed with the use of c-index models. There was some evidence of between-centre heterogeneity, especially when examining continuous counts of CTCs.

CONCLUSIONS

These data confirm CTCs as an independent prognostic indicator of progression-free survival and overall survival in advanced NSCLC and also reveal some evidence of between-centre heterogeneity. CTC count improves prognostication when added to full clinicopathological predictive models.

Prognostic value of circulating tumour cells in limited-stage small-cell lung cancer: analysis of the concurrent once-daily versus twice-daily radiotherapy (CONVERT) randomised controlled trial

BACKGROUND

The clinical significance of circulating tumour cells (CTCs) in limited-stage small-cell lung cancer (LS-SCLC) is not well defined. We report a planned exploratory analysis of the prevalence and prognostic value of CTCs in LS-SCLC patients enrolled within the phase III randomised CONVERT (concurrent once-daily versus twice-daily chemoradiotherapy) trial.

PATIENTS AND METHODS

Baseline blood samples were enumerated for CTCs using CellSearch in 75 patients with LS-SCLC who were enrolled in the CONVERT trial and randomised between twice- and once-daily concurrent chemoradiation. Standard statistical methods were used for correlations of CTCs with clinical factors. Log-rank test and Cox regression analyses were applied to establish the associations of 2, 15 and 50 CTC thresholds with progression-free survival (PFS) and overall survival (OS). An optimal CTC count threshold for LS-SCLC was established.

RESULTS

CTCs were detected in 60% (45/75) of patients (range 0-3750). CTC count thresholds of 2, 15 and 50 CTCs all significantly correlate with PFS and OS. An optimal CTC count threshold in LS-SCLC was established at 15 CTCs, defining 'favourable' and 'unfavourable' prognostic risk groups. The median OS in <15 versus ≥15 CTCs was 26.7 versus 5.9 m (P = 0.001). The presence of ≥15 CTCs at baseline independently predicted ≤1 year survival in 70% and ≤2 years survival in 100% of patients.

CONCLUSION

We report the prognostic value of baseline CTC count in an exclusive LS-SCLC population at thresholds of 2, 15 and 50 CTCs. Specific to LS-SCLC, ≥15 CTCs was associated with worse PFS and OS independent of all other factors and predicted ≤2 years survival. These results may improve disease stratification in future clinical trial designs and aid clinical decision making.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00433563.

KRAS: Reasons for optimism in lung cancer

Despite being the most frequent gain-of-function genetic alteration in human cancer, KRAS mutation has to date offered only limited potential as a prognostic and predictive biomarker. Results from the phase III SELECT-1 trial in non-small cell lung cancer (NSCLC) recently added to a number of historical and more contemporary disappointments in targeting KRAS mutant disease, including farnesyl transferase inhibition and synthetic lethality partners such as STK33. This narrative review uses the context of these previous failures to demonstrate how the knowledge gained from these experiences can be used as a platform for exciting advances in NSCLC on the horizon. It now seems clear that mutational subtype (most commonly G12C) of individual mutations is of greater relevance than the categorical evaluation of KRAS mutation presence or otherwise. A number of direct small molecules targeted to these subtypes are in development and have shown promising biological activity, with some in the late stages of preclinical validation.

CD52, CD22, CD26, EG5 and IGF-1R expression in thymic malignancies

BACKGROUND

Thymic epithelial tumours are rare cancers for which new treatment options are required. Identification of putative predictive markers is important for developing clinical trials. We studied the expression of five putative predictive biomarkers, potentially actionable by approved experimental drugs.

METHODS

CD52, CD22, CD26, EG5, and IGF-1R expression were investigated by immunohistochemistry in formalin-fixed surgical samples of thymic epithelial tumour patients. All samples containing 10% positive epithelial tumour cells, independent of tumour cell intensity, were considered as positive. Correlation with histological subtype was performed.

RESULTS

106 surgical samples (89 thymomas, 12 thymic carcinoma, and 5 thymic neuroendocrine tumours) were evaluated. Overall, CD52, CD22, CD26, EG5 and IGF-1R expression was observed in 7%, 42%, 25%, 42% and 77% of samples, respectively. CD52 expression was more frequent in B2 and B3 thymoma. All TET subtypes stained for CD22, mainly AB thymoma (68%). CD26 expression also correlated with AB thymoma (68%), and A thymoma (50%) subtype, while IGFR1 was the most common marker expressed by thymic carcinoma samples (92%), followed by EG5 (60%). Only EG5 expression was significantly higher in thymic carcinomas than in thymomas (75% vs. 38%, p=0.026).

CONCLUSIONS

Our data were consistent with a previous study of IGF-1R expression. Based on their expression, activity of agents targeting CD52, CD 22, CD26 and EG5 could be further explored in TET patients.

Vimentin and Ki67 expression in circulating tumour cells derived from castrate-resistant prostate cancer

Background

High circulating tumor cell (CTC) counts are associated with poor prognosis in advanced prostate cancer, and recently CTC number was suggested to be a surrogate for survival in metastatic castrate-resistant prostate cancer (mCRPC). Ki67 and vimentin are well-characterised markers of tumour cell proliferation and the epithelial-mesenchymal transition (EMT), respectively. Here we asked if the expression of vimentin and Ki67 in CTCs offered prognostic or predictive information in mCRPC.

Methods

In two separate patient cohorts, anti-vimentin or anti-Ki67 antibodies were added to the free channel in the CellSearch® system for analysis of peripheral blood samples. For each cohort, association of CTC number with clinical characteristics were assessed using Fisher’s exact, Mann-Whitney and chi-squared tests. Kaplan-Meier method and log-rank tests were used to analyse overall survival (OS) of vimentin-expressing and Ki67-expressing CTC patient cohorts.

Results

In this retrospective analysis, CTC vimentin expression was analysed in 142 blood samples from 93 patients, and CTC Ki67 expression was analysed in 90 blood samples from 51 patients. In the vimentin cohort, 80/93 (86 %) of baseline samples from patients were CTC-positive overall (≥1 total CTC per 7.5 mls blood), and 30/93 (32.3 %) vimentin CTC-positive (≥1 vimentin-positive CTC per 7.5 mls blood). 41/51 (80.4 %) of baseline samples from patients in the Ki67 cohort were CTC-positive overall, and 23/51 (45.1 %) Ki67 CTC-positive (≥1 Ki67-positive CTC per 7.5 mls blood). There was no significant difference in baseline PSA in patients with vimentin-positive CTC at baseline versus those with no vimentin-positive CTC at baseline (p = 0.33). A significant reduction in OS was shown in patients with vimentin-positive CTC compared to those without vimentin-positive CTC (median 305 days vs 453 days, p = 0.0293). There was no significant difference in baseline PSA in patients with Ki67-positive CTC at baseline versus those without Ki67-positive CTC (p = 0.228), but OS was significantly reduced in the Ki67-positive CTC group (median 512 days vs 751 days, p = 0.0091). No changes in relative proportion of vimentin- or Ki67-positive CTCs were observed in post-treatment samples compared to baseline.

Conclusions

Analysis of vimentin and Ki67 expression can straightforwardly be assessed in CTCs from patients with mCRPC. Poorer survival outcomes were observed in vimentin- and Ki67-positive CTC patients.

Translational study protocols

CEC-CTC (IDRCB2008-AOO585-50) and Petrus (NCT01786031).

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2192-6) contains supplementary material, which is available to authorized users.

High level of chromosomal instability in circulating tumor cells of ROS1-rearranged non-small-cell lung cancer

ROS1-rearrangement can be detected in circulating tumor cells of ROS1-rearranged non-small-cell lung cancer patients, offering perspectives for diagnosing patients eligible for ROS1-inhibitor therapy. ROS1-rearranged CTCs show considerable heterogeneity of ROS1-gene abnormalities and elevated numerical chromosomal instability, a potential mechanism of resistance to ROS1-inhibitor.

Background

Genetic aberrations affecting the c-ros oncogene 1 (ROS1) tyrosine kinase gene have been reported in a small subset of patients with non-small-cell lung cancer (NSCLC). We evaluated whether ROS1-chromosomal rearrangements could be detected in circulating tumor cells (CTCs) and examined tumor heterogeneity of CTCs and tumor biopsies in ROS1-rearranged NSCLC patients.

Patients and methods

Using isolation by size of epithelial tumor cells (ISET) filtration and filter-adapted-fluorescence in situ hybridization (FA-FISH), ROS1 rearrangement was examined in CTCs from four ROS1-rearranged patients treated with the ROS1-inhibitor, crizotinib, and four ROS1-negative patients. ROS1-gene alterations observed in CTCs at baseline from ROS1-rearranged patients were compared with those present in tumor biopsies and in CTCs during crizotinib treatment. Numerical chromosomal instability (CIN) of CTCs was assessed by DNA content quantification and chromosome enumeration.

Results

ROS1 rearrangement was detected in the CTCs of all four patients with ROS1 rearrangement previously confirmed by tumor biopsy. In ROS1-rearranged patients, median number of ROS1-rearranged CTCs at baseline was 34.5 per 3 ml blood (range, 24–55). In ROS1-negative patients, median background hybridization of ROS1-rearranged CTCs was 7.5 per 3 ml blood (range, 7–11). Tumor heterogeneity, assessed by ROS1 copy number, was significantly higher in baseline CTCs compared with paired tumor biopsies in the three patients experiencing PR or SD (P < 0.0001). Copy number in ROS1-rearranged CTCs increased significantly in two patients who progressed during crizotinib treatment (P < 0.02). CTCs from ROS1-rearranged patients had a high DNA content and gain of chromosomes, indicating high levels of aneuploidy and numerical CIN.

Conclusion

We provide the first proof-of-concept that CTCs can be used for noninvasive and sensitive detection of ROS1 rearrangement in NSCLC patients. CTCs from ROS1-rearranged patients show considerable heterogeneity of ROS1-gene abnormalities and elevated numerical CIN, a potential mechanism to escape ROS1-inhibitor therapy in ROS1-rearranged NSCLC tumors.

Phase I dose escalation study of continuous oral dosing of OSI-906, an insulin like growth factor-1 receptor (IGF-1R) tyrosine kinase inhibitor, in patients with advanced solid tumors

2559

Background: OSI-906 is a potent small molecule inhibitor of IGF-1R, a receptor tyrosine kinase activated by insulin like growth factor, which is overexpressed in numerous malignancies and implicated in resistance to chemotherapy. Methods: Patients with advanced cancer entered escalating dose cohorts of OSI-906. Study objectives included assessment of: safety; determination of MTD; pharmacokinetics (PK), pharmacodynamics (PD) including IGF-1R levels in peripheral blood cells; and tumor response (RECIST). Results: To date, 32 pts have been treated (22M/10F, median age 62y) at 10, 20, 40, 75, 150, and 300 mg QD and at 20, 40 mg and 75 mg BID. Median number of weeks on trial was 6 (range 0–44). No DLTs have been observed. Hyperglycemia (5/20 pts) related to OSI-906 was transient and mild (grade 1 only). In addition to hyperglycemia, grade 1–2 nausea and vomiting (5/20 pts) were the most frequent related adverse events (AEs). There was grade 3 elevated lipase in 1 pt. At doses of 10–150 mg, OSI-906 exhibited linear PK, median terminal t1/2 ranged from 2.18–4.30 hr, AUC0-inf from 284–10200 ng.hr/mL, and Cmax 76.6–1440 ng/mL. There was no relationship between glucose or insulin levels and OSI-906 plasma concentrations. Stable disease > 12 weeks was seen in 7/20 pts (range 12–34 weeks), including 1 pt each with thymic (27 w), adrenocortical (28w), and colorectal (34w) cancer. PD data on IGF-1R phosphorylation will be presented. Conclusions: Plasma concentrations of OSI-906 achieved in this trial exceed concentrations required for antitumor efficacy in preclinical models. PD target modulation and preliminary anti-tumor activity have been observed. It is interesting to note that clinically meaningful hyperglycemia has yet to occur. Minimal toxicity was observed and further dose escalation is in progress.

[Table: see text]