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Objectives: Mutational signatures (MS) are gaining traction for deriving therapeutic insights for immune checkpoint inhibition (ICI). We asked if MS attributions from comprehensive targeted sequencing assays are reliable enough for predicting ICI efficacy in non-small cell lung cancer (NSCLC).Methods: Somatic mutations of m=126 patients were assayed using panel-based sequencing of 523 cancer-related genes. In silico simulations of MS attributions for various panels were performed on a separate dataset of m=101 whole genome sequenced patients. Non-synonymous mutations were deconvoluted using COSMIC v3.3 signatures and used to test a previously published machine learning classifier. Results: The ICI efficacy predictor performed poorly with an accuracy of {0.51}_{-0.09}^{+0.09}, average precision of {0.52}_{-0.11}^{+0.11}, and an area under the receiver operating characteristic curve of {0.50}_{-0.09}^{+0.10}. Theoretical arguments, experimental data, and in silico simulations pointed to false negative rates (FNR) related to panel size. A secondary effect was observed, where deconvolution of small ensembles of point mutations lead to reconstruction errors and misattributions.Conclusion: MS attributions from current targeted panel sequencing are not reliable enough to predict ICI efficacy. We suggest that, for downstream classification tasks in NSCLC, signature attributions be based on whole exome or genome sequencing instead.

Background: First-line durvalumab plus etoposide with either cisplatin or carboplatin (platinum–etoposide) showed a significant improvement in overall survival versus platinum–etoposide alone in patients with extensive-stage small-cell lung cancer (ES-SCLC) in the CASPIAN study. Here we report updated results, including the primary analysis for overall survival with durvalumab plus tremelimumab plus platinum–etoposide versus platinum–etoposide alone. Methods: CASPIAN is an ongoing, open-label, sponsor-blind, randomised, controlled phase 3 trial at 209 cancer treatment centres in 23 countries worldwide. Eligible patients were aged 18 years or older (20 years in Japan) and had treatment-naive, histologically or cytologically documented ES-SCLC, with a WHO performance status of 0 or 1. Patients were randomly assigned (1:1:1) in blocks of six, stratified by planned platinum, using an interactive voice-response or web-response system to receive intravenous durvalumab plus tremelimumab plus platinum–etoposide, durvalumab plus platinum–etoposide, or platinum–etoposide alone. In all groups, patients received etoposide 80–100 mg/m2 on days 1–3 of each cycle with investigator's choice of either carboplatin area under the curve 5–6 mg/mL/min or cisplatin 75–80 mg/m2 on day 1 of each cycle. Patients in the platinum–etoposide group received up to six cycles of platinum–etoposide every 3 weeks and optional prophylactic cranial irradiation (investigator's discretion). Patients in the immunotherapy groups received four cycles of platinum–etoposide plus durvalumab 1500 mg with or without tremelimumab 75 mg every 3 weeks followed by maintenance durvalumab 1500 mg every 4 weeks. The two primary endpoints were overall survival for durvalumab plus platinum–etoposide versus platinum–etoposide and for durvalumab plus tremelimumab plus platinum–etoposide versus platinum–etoposide in the intention-to-treat population. Safety was assessed in all patients who received at least one dose of study treatment. This study is registered at ClinicalTrials.gov, NCT03043872. Findings: Between March 27, 2017, and May 29, 2018, 972 patients were screened and 805 were randomly assigned (268 to durvalumab plus tremelimumab plus platinum–etoposide, 268 to durvalumab plus platinum–etoposide, and 269 to platinum–etoposide). As of Jan 27, 2020, the median follow-up was 25·1 months (IQR 22·3–27·9). Durvalumab plus tremelimumab plus platinum–etoposide was not associated with a significant improvement in overall survival versus platinum–etoposide (hazard ratio [HR] 0·82 [95% CI 0·68–1·00]; p=0·045); median overall survival was 10·4 months (95% CI 9·6–12·0) versus 10·5 months (9·3–11·2). Durvalumab plus platinum–etoposide showed sustained improvement in overall survival versus platinum–etoposide (HR 0·75 [95% CI 0·62–0·91]; nominal p=0·0032); median overall survival was 12·9 months (95% CI 11·3–14·7) versus 10·5 months (9·3–11·2). The most common any-cause grade 3 or worse adverse events were neutropenia (85 [32%] of 266 patients in the durvalumab plus tremelimumab plus platinum–etoposide group, 64 [24%] of 265 patients in the durvalumab plus platinum–etoposide group, and 88 [33%] of 266 patients in the platinum–etoposide group) and anaemia (34 [13%], 24 [9%], and 48 [18%]). Any-cause serious adverse events were reported in 121 (45%) patients in the durvalumab plus tremelimumab plus platinum–etoposide group, 85 (32%) in the durvalumab plus platinum–etoposide group, and 97 (36%) in the platinum–etoposide group. Treatment-related deaths occurred in 12 (5%) patients in the durvalumab plus tremelimumab plus platinum–etoposide group (death, febrile neutropenia, and pulmonary embolism [n=2 each]; enterocolitis, general physical health deterioration and multiple organ dysfunction syndrome, pneumonia, pneumonitis and hepatitis, respiratory failure, and sudden death [n=1 each]), six (2%) patients in the durvalumab plus platinum–etoposide group (cardiac arrest, dehydration, hepatotoxicity, interstitial lung disease, pancytopenia, and sepsis [n=1 each]), and two (1%) in the platinum–etoposide group (pancytopenia and thrombocytopenia [n=1 each]). Interpretation: First-line durvalumab plus platinum–etoposide showed sustained overall survival improvement versus platinum–etoposide but the addition of tremelimumab to durvalumab plus platinum–etoposide did not significantly improve outcomes versus platinum–etoposide. These results support the use of durvalumab plus platinum–etoposide as a new standard of care for the first-line treatment of ES-SCLC. Funding: AstraZeneca.

Daily-practice challenges in oncology have been intensified by the approval of immune checkpoint inhibitors (ICI). We aimed to outline current therapy policies and management of locally advanced unresectable stage III non-small-cell lung cancer (NSCLC) in different countries. One thoracic oncologist from each of the following countries-Belgium, Croatia, Greece, Israel, the Netherlands, Norway, Poland, Portugal, Romania, Slovenia, and Switzerland-participated in an electronic survey. Descriptive statistics were conducted with categorical variables reported as frequencies and continuous variables as median and interquartile range (IQR) (StataSE-v15). EBUS (endobronchial ultrasound bronchoscopy) was used either upfront or for N2 confirmation. Resectability is still a source of disagreement; thus, decisions vary within each multidisciplinary team. Overall, 66% of stage III patients [IQR 60-75] undergo chemoradiation therapy (CRT); concurrent CRT (cCRT) accounts for most cases (similar to 70%). Performance status is universally used for cCRT eligibility. Induction chemotherapy is fairly weighted based on radiotherapy (RT) availability. Mean time to evaluation after RT completion is less than a month; ICI consolidation is started within six weeks. Durvamulab expenditures are reimbursed in all countries, yet some limiting criteria exist (PD-L1 >= 1%, cCRT). No clear guidance on therapies at Durvamulab progression exist; experts agree that it depends on progression timing. Given the high heterogeneity in real-world practices, standardized evidence-based decisions and healthcare provision in NSCLC are needed. AstraZeneca

Background: Most patients with small-cell lung cancer (SCLC) have extensive-stage disease at presentation, and prognosis remains poor. Recently, immunotherapy has demonstrated clinical activity in extensive-stage SCLC (ES-SCLC). The CASPIAN trial assessed durvalumab, with or without tremelimumab, in combination with etoposide plus either cisplatin or carboplatin (platinum–etoposide) in treatment-naive patients with ES-SCLC. Methods: This randomised, open-label, phase 3 trial was done at 209 sites across 23 countries. Eligible patients were adults with untreated ES-SCLC, with WHO performance status 0 or 1 and measurable disease as per Response Evaluation Criteria in Solid Tumors, version 1.1. Patients were randomly assigned (in a 1:1:1 ratio) to durvalumab plus platinum–etoposide; durvalumab plus tremelimumab plus platinum–etoposide; or platinum–etoposide alone. All drugs were administered intravenously. Platinum–etoposide consisted of etoposide 80–100 mg/m2 on days 1–3 of each cycle with investigator's choice of either carboplatin area under the curve 5–6 mg/mL per min or cisplatin 75–80 mg/m2 (administered on day 1 of each cycle). Patients received up to four cycles of platinum–etoposide plus durvalumab 1500 mg with or without tremelimumab 75 mg every 3 weeks followed by maintenance durvalumab 1500 mg every 4 weeks in the immunotherapy groups and up to six cycles of platinum–etoposide every 3 weeks plus prophylactic cranial irradiation (investigator's discretion) in the platinum–etoposide group. The primary endpoint was overall survival in the intention-to-treat population. We report results for the durvalumab plus platinum–etoposide group versus the platinum–etoposide group from a planned interim analysis. Safety was assessed in all patients who received at least one dose of their assigned study treatment. This study is registered at ClinicalTrials.gov, NCT03043872, and is ongoing. Findings: Patients were enrolled between March 27, 2017, and May 29, 2018. 268 patients were allocated to the durvalumab plus platinum–etoposide group and 269 to the platinum–etoposide group. Durvalumab plus platinum–etoposide was associated with a significant improvement in overall survival, with a hazard ratio of 0·73 (95% CI 0·59–0·91; p=0·0047]); median overall survival was 13·0 months (95% CI 11·5–14·8) in the durvalumab plus platinum–etoposide group versus 10·3 months (9·3–11·2) in the platinum–etoposide group, with 34% (26·9–41·0) versus 25% (18·4–31·6) of patients alive at 18 months. Any-cause adverse events of grade 3 or 4 occurred in 163 (62%) of 265 treated patients in the durvalumab plus platinum–etoposide group and 166 (62%) of 266 in the platinum–etoposide group; adverse events leading to death occurred in 13 (5%) and 15 (6%) patients. Interpretation: First-line durvalumab plus platinum–etoposide significantly improved overall survival in patients with ES-SCLC versus a clinically relevant control group. Safety findings were consistent with the known safety profiles of all drugs received. Funding: AstraZeneca.

It is increasingly understood that cancers can be recognized by the immune system and that inflammation relates to response. Combining stereotactic radiotherapy (SBRT) to increase release of cancer cell antigens with an anti-CTLA-4 and PD-L1 inhibitor may lead to increased response rates. Due to tumor heterogeneity it may be important to irradiate the primary tumor (addressing trunk mutations), instead of its metastasis (branch mutations). No solid predictive biomarker for response and/or immunotherapy related adverse events (TRAEs) is available. Electronic nose (eNose) technology measures the complete mixture of volatile organic compounds in exhaled breath and can detect lung cancer based on pattern recognition of the breath profile. We hypothesize that eNose is able to predict TRAEs and response in patients with NSCLC. Methods: In 3 sequential cohorts, immunotherapy regimes combined with SBRT were studied in stage IIIB/IV NSCLC patients progressing on chemotherapy. All patients were irradiated on the primary tumor (1x20 Gy on 9cc) 1 week after the 1st dose of immunotherapy. The 1st cohort (n=3) received durvalumab. The 2nd and 3rd cohort (both n=6) received a combination of durvalumab and tremelimumab followed by durvalumab monotherapy. Duplicate eNose measurements were performed by using the SpiroNose that contains 7 metal oxide semiconductor sensors. TRAEs were categorized using NCI CTCAE version 4.3. Descriptive statistics were used to summarize baseline characteristics and TRAEs. The relationship between breath profiles and response and TRAEs was analyzed with advanced signal processing, ambient correction and Mann-Whitney U test. Linear discriminant and receiver operating characteristics analysis followed. Pearson correlation and regression assessed duration of response. Findings: Fifteen patients were included as described above. Baseline characteristics of the groups were comparable. Median progression free survival was 2 months, overall survival 10 months (immature). No statistical difference was found in (duration of) response. There was 1 low grade TRAE (CTC 1-2) in cohort 1 and 10 in cohort 2/3. High grade TRAEs (CTC 3) were only present in cohort 2/3 (n=3) and 1 patient discontinued treatment. There was one dose limiting toxicity. At baseline, 12/15 patients performed eNose measurements; 7 with TRAEs and 5 without. The TRAE group had a significant higher sensor 7 signal compared to those without TRAE (p=.042). The cross-validated accuracy for detecting TRAE was 67%. The ROC-AUC was .857 [.638-1]. Interpretation: eNose breath profiles at baseline may predict which patients will develop TRAEs. The small sample size increases the risk of overfitting, therefore another cohort of 34 immuno-monotherapy patients is being analyzed (15 with and 19 without TRAEs, pending). We demonstrated no new safety data. Disclosure: This study was sponsored by a research grant from AstraZeneca. Citation Format: M Benthe Muntinghe-Wagenaar, Hanneke Kievit, Lucie B. Hijmering-Kappelle, Birgitta I. Hiddinga, J Fred Ubbels, Robin Wijsman, Mechteld F. Brasz, Gitte Slingers, Rianne de Vries, Milou M. Schuurbiers, Harry J. Groen, Huib A. Kerstjens, Anthonie J. van der Wekken, Michel M. van den Heuvel, T Jeroen Hiltermann. A phase 1 study to detect adverse events after SBRT and immunotherapy by electronic nose in advanced NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 666.

It is increasingly understood that cancers can be recognized by the immune system and inflammation relates to response. Combining stereotactic radiotherapy (SBRT), to increase release of cancer cell antigens, with an anti-CTLA-4 and PD-L1 inhibitor may lead to increased response rates. No solid biomarker in predicting treatment response is available. We set out to study feasibility of combined durvalumab (anti-PD-L1) and tremelimumab (anti-CTLA-4) with SBRT on the primary tumor. The extend of tumor-infiltrating cells has shown to correlate to improved prognosis using checkpoint inhibitor (CPI) treatment of various cancers. We hypothesized that the peripheral blood T-cell activation status may be a predictor of response, progression free survival (PFS) and overall survival (OS). Methods: Three immunotherapy regimes were combined with SBRT in sequential cohorts as ≥2nd line in CPI naïve patients with NSCLC stage IIIB/IV. One week after the 1st dose of CPI, patients were irradiated on the primary tumor (1x 20Gy on 9cc). The 1st cohort (n=3) received durvalumab, the 2nd and 3rd cohort (both n=6) a combination of durvalumab and tremelimumab, followed by durvalumab monotherapy. Exploratory endpoint was the correlation of response with T-cell function. T-cell function was assessed using flow cytometric analysis of peripheral blood T-cells and compared to simultaneously included healthy controls. In short, whole blood was activated ex vivo using Staphylococcal enterotoxin B (SEB) after which the T-cell activation status was assesses by expression of CD69 and cytokines (IL-2, IFN-γ, TNF-α). Patients were divided in above (responders, R) and below median PFS (non-responders, NR). We compared intracellular cytokine production in both CD4+ and CD8+ T-lymphocytes between both groups and with healthy controls (HC) using the Mann-Whitney U test. Findings: Fifteen patients were included as described above. Median PFS was 2 months, OS 10 months (immature). Baseline characteristics of both groups were comparable. T-cell function was assessed in 14 patients and HC at baseline. Data are shown as median (P-value) for R vs NR below. R had a significant higher percentage activated CD8+ T-cells upon SEB stimulation than NR: CD8+CD69+ 15.8 vs 3.5 (0.008) and IL-2+CD8+CD69+ 8.8 vs 2.9 (0.02). There was a trend in TNF-α+CD8+CD69+ 19.8 vs 8.0 (0.11) and IFN-ɣ+CD8+CD69+ 21.4 vs 5.5 (0.22). These differences were all significant for R compared to HC (p0.66). Interpretation: With a mild antigen independent stimulus (SEB), the CD8+ T-cells of responders were significantly more activated at baseline compared to non-responders and healthy controls. This suggests an elevated pre-treatment T-cell activation status in patients that responded to the treatment and the possibility to use this as a potential biomarker to predict the response to CPI treatment. Disclosure: This study was sponsored by a research grant from AstraZeneca. Citation Format: Hanneke Kievit, M. Benthe Muntinghe-Wagenaar, Lucie B.M. Hijmering-Kappelle, Birgitta I. Hiddinga, J Fred Ubbels, Robin Wijsman, Bart-Jan Kroesen, Marcel J. van der Leij, A. Rutgers, Harry J. Groen, Huib A. Kerstjens, Anthonie J. van de Wekken, T Jeroen Hiltermann. Baseline T-cell function predicts response to SBRT and immunotherapy in NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1984.

BackgroundNowadays, the detection of therapy-guiding aberrations such as EGFR mutations and ALK fusion genes in tumor tissue is common practice for lung cancer patients. The aim of this study is to explore the feasibility of detecting common therapy-guiding aberrations in RNA isolated from platelets.MethodsWe applied a single primed enrichment-based targeted next generation sequencing (NGS) approach on 10 platelet RNA samples isolated from patients with active disease. In parallel, we applied RNA-based ddPCR focusing on EGFR p.(T790M), p.(L858R) and E19del, on KRAS codon 12 and 13 and on ALK-EML4/KIF5B fusions on 22 platelet RNA samples from patients with tumors known to harbor one of these drivers. For 11 cases ddPCR analysis of circulating cell free (cf)DNA from the same blood sample was performed in parallel.ResultsDespite having good quality NGS data, none of the variants detected in the tumor biopsy were observed in platelet-derived RNA samples. Using the more sensitive ddPCR, we detected known aberrations in three of 22 platelet-derived RNA samples. EGFR mutant droplets were not observed in any of the seven platelet samples, while these mutations were detected in three of six cfDNA samples of which five were extracted from the same blood sample. KRAS mutant droplets were detected in three out of nine platelet RNA samples with fractional abundances of 0.07%, 0.11% and 0.55%. Analysis of five cfDNA samples from the same blood samples revealed KRAS-mutant droplets in four of them. Two of the four corresponding platelet RNA samples were also positive for mutant KRAS. No ALK fusion droplets were detected in seven platelet derived RNA samples.ConclusionsThe level of tumor-derived RNA transcripts in platelets of non-small cell lung cancer patients was too low to be measured reliably for clinically relevant alterations in EGFR, KRAS and ALK fusion gene transcripts.

Background. In the past decade, treatment of advanced stage lung cancer patients guided by somatic aberrations has become routine practice. Different molecular tests are being applied to detect all targetable mutations and fusions. However, in most cases tissue biopsies are small, hampering multiple independent diagnostic tests. To optimize diagnostic testing we developed an all-in-one transcriptome-based assay. Methods. We have developed a targeted next generation sequencing protocol that uses total RNA as input and is based on the Single Primed enrichment Technology (SPET). We included 11 cell lines, four frozen biopsies, 12 pleural effusion samples and 32 FFPE samples with in total 41 known mutations (including EGFR n=15; KRAS n=11; BRAF n=2; PIK3CA n=3 ), 21 fusion genes (including ALK n=15; ROS n=3) and 3 cases of MET exon14 skipping. Results. We confirmed presence of 32 out of 41 mutations, 19 out of 23 fusions and all three cases of exon skipping by our assay. Besides confirming the fusions, we were also able to identify the fusion gene partner for all detected fusion transcripts. For the samples for which we failed to detect the mutations or fusions, the read depth of the target region was less than four, indicating low expression, low tumor content or insufficient unique reads. Independent RNA-based ddPCR on six unconfirmed mutations were all positive, albeit with low numbers of mutant droplets in some cases. One of three undetected fusions was positive in a NanoString fusion gene detection assay. For one of two negative cases, the fusion was most likely false positive by FISH, as this patient was FISH-break positive for both ALK and RET, which is never reported before. Conclusions. This study proved feasibility of this targeted all-in-one transcriptome-based assay for simultaneous detection of mutations and fusions even in relatively small FFPE tissue biopsies. Moreover, we were able to detect the fusion partner genes in all positive cases. We expect that for routine diagnostic testing using an enrichment for tumor cell-rich areas of recently prepared FFPE blocks, the success rate of the all-in-one transcriptome approach will reach similar sensitivity as currently used diagnostic tests. Citation Format: Klaas Kok, Jiacong Wei, Anna A. Rybczynska, Pei Meng, Martijn M. Terpstra, Anthonie J. van der Wekken, Jeroen T. Hiltermann, Ed Schuuring, Harry J. Groen, Anke van den Berg. An all-in-one transcriptome-based assay to identify therapy-related biomarkers in lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2989.

Introduction: PD-L1 expression has been approved as predictive biomarker for immune checkpoint inhibitors (ICI) in non-small cell lung carcinoma (NSCLC). In case of lack of PD-L1 expression in tumor biopsies, 8-10% of patients will respond to ICI. However, in case of > 50% PD-L1 tumor expression half of patients show no response. Tumor immune escape phenotypes are characterized by loss of MHC-class-I and a lower grade of CD8 T-cell infiltration, despite upregulation of PD-L1 expression. At least one of the four phenotypes of MHC-class-I and PD-L1 co-expression is considered responsible for non-responsiveness. We investigated the frequency of PD-L1, MHC-class-I β2-microglobulin (β-2M) co-expression and presence of CD8 cells in advanced NSCLC. Methods: Analysis was performed on formalin fixed, paraffin embedded (FFPE) transbronchial or transthoracic tumor biopsies of 27 patients with advanced NSCLC. Immunohistochemistry was performed using Ventana Benchmark Ultra immunostainer. PD-L1 was detected using Ventana PD-L1 (SP263) Assay (CE IVD), CD8 by Ventana CONFIRM anti-CD8 (SP57) antibody and MHC-class I β2-M by Agilent-Dako polyclonal rabbit anti-human beta-2-Microglobulin. PDL1 expression was scored as percentage positive tumor cells according to the manufacturers guideline, β2-M was scored as positive or negative in tumor cells and CD8 cells as low (+), intermediate (++) or high (+++) numbers in tumor or peritumoral stroma. Results: In 27 patients IHC staining was performed. PDL1 expression was scored as 1%) patients had positive β-2M in 10 of 10 cases. PD-L1 negative tumors showed presence of β-2M in 10 of 17 cases. Seven out of 27 cases (26%) were β-2M negative; all of them were PD-L negative cases. Low CD8 score was seen in 7 patients and 2 of these patients have a PD-L1 expression >1% and positive β-2M. Conclusion: In this ongoing study one quarter of advanced NSCLC patients had no tumor MHC-class-1 β-2M expression. In our cohort β-2M negative phenotype was associated with lack of PD-L1 tumor expression. Citation Format: Lucie Hijmering-Kappelle, Jeroen Hiltermann, Birgitta Hiddinga, Anthonie van der Wekken, Nils 't Hart, Harry Groen, Wim Timens. PD-L1 expression, CD8 cells and MHC-class-1 Beta-2-microglobulin expression in advanced non-small lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4067.

Background: Programmed death-ligand 1 (PD-L1) expression has been associated with response to PD-1/PD-L1 inhibition, but responses are also seen in patients with PD-L1 negative tumors when assessed immunohistochemically (IHC) with various antibodies. To help understand these findings, we performed a first-in-human positron emission tomography (PET) imaging study with the anti-PD-L1 antibody atezolizumab labeled with zirconium-89 (89Zr) prior to treatment with atezolizumab to assess normal organ distribution and evaluate tumor tracer uptake in relation to PD-L1 IHC in archival and post-tracer tumor specimen and ultimately to treatment response. Methods: Patients with locally advanced or metastatic non-small cell lung cancer (NSCLC), bladder cancer (BC) or triple-negative breast cancer (TNBC) received 10 mg unlabeled atezolizumab plus 37 MBq 89Zr-atezolizumab (~1 mg) followed by up to 4 PET scans (1 hour, days 2, 4 and 7 post-injection (pi)). Next, after obtaining a tumor biopsy for PD-L1 IHC 8-10 days after tracer injection, patients received atezolizumab (1200 mg) i.v. once every 3 weeks until disease progression (NCT02453984 and NCT02478099). Response was assessed every 6 weeks with RECIST1.1. Normal organ tracer uptake was calculated as percentage of the injected dose/kg (%ID/kg) 4 and 7 days pi, tumor tracer uptake as maximum standardized uptake value (SUVmax) and %ID/kg 7 days pi. Tumor biopsy PD-L1 expression was assessed in tumor cells (TC) and tumor infiltrating immune cells (IC) by HistoGeneX IHC with the SP142 assay (Ventana). Results: In this ongoing trial, 16/25 patients completed the PET series and received atezolizumab at least until the first response assessment. The median follow-up of these patients is 16 weeks (6-40+, NSCLC=6, BC=8, TNBC=2). The highest normal organ 89Zr-atezolizumab uptake was seen in the spleen (16.3±3.6 %ID/kg 4 days and 17.9±3.6 %ID/kg 7 days pi), and uptake in other lymphatic organs (single normal lymph nodes and tonsil) and sites of (chronic) inflammation (e.g. chronic sinusitis and bursitis) were detected. Uptake in liver, kidney and intestine was similar to other antibodies with 7.3±1.6, 5.5±2.0 and 4.7±2.4 %ID/kg, respectively, 7 days pi. Tumor SUVmax ranged between 1.6 and 46.0 (1.8-12.4 %ID/kg), with an up to 9-fold difference within patients, and 4-fold difference between patients. In 4 biopsied lesions with IC/TC 0, 89Zr-atezolizumab uptake calculated as SUVmax was 10.0±3.6 (7.1±1.6 %ID/kg). At this time only 4 biopsies had a IHC score of 2+ on either IC or TC, and there were no biopsies with a score of 3+, limiting the ability to determine correlation of PD-L1 IHC to imaging data. Conclusion: 89Zr-atezolizumab imaging showed high uptake in normal spleen, other normal lymphoid organs and regions of inflammation. Uptake in tumor lesions was heterogeneous within and between patients and even PD-L1 IHC 0 tumors showed clear tracer uptake. Citation Format: Frederike Bensch, Elly van der Veen, Annelies Jorritsma, Marjolijn Lub-de Hooge, Ronald Boellaard, Sjoukje Oosting, Carolien Schröder, Jeroen Hiltermann, Anthonie van der Wekken, Harry Groen, Bernard Fine, Nathan McKnight, Sandra Sanabria Bohorquez, Simon Williams, Luisa Veronese, Christoph Mancao, Adrienne H. Brouwers, Elisabeth de Vries. First-in-human PET imaging with the PD-L1 antibody 89Zr-atezolizumab [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT017. doi:10.1158/1538-7445.AM2017-CT017

A 57-year-old woman with advanced non-small cell lung carcinoma developed hypersensitivity reactions to docetaxel. Measures taken to attempt the re-administration of docetaxel failed. For the differential diagnosis, an IgE specific to docetaxel (in terms of cross-reactivity with Taxus baccata), the solubilizing agent polysorbate 80, as well as the possibility of the reaction being non-IgE-mediated, were all considered. The latter was thought to be most likely. Desensitisation has been reported to be safe and effective in protecting patients from severe hypersensitivity reactions in both IgE- and non-IgE-mediated reactions. Desensitisation in this context means the induction of temporary clinical unresponsiveness to the culprit drug. The gradual reintroduction of small doses of the drug at fixed time intervals eventually allows delivery of full therapeutic doses. Desensitisation to docetaxel was successfully carried out in a supervised setting a total of three times in this patient.

Purpose: The presence of Circulating Tumor Cells (CTC) in metastatic carcinomas detected by CellSearch is associated with poor outcome. CellSearch uses an enrichment step based on the EpCAM antibody and enumerates CTC using antibodies targeting specific cytokeratins. Here we investigate the presence and role of CTC not detected by CellSearch in lung cancer patients. Methods: Blood discarded by CellSearch after EpCAM based enrichment was collected and enriched for CTC by filtration through microsieves and enumerated after fluorescent labeling. Additional anti-cytokeratin antibodies were added to the CellSearch test to increase the cytokeratin coverage. This approach was validated using different cell lines spiked into blood and tested on blood samples of 28 metastatic lung cancer patients. Results: The majority of spiked EpCAM+ cells could be detected with CellSearch whereas few cells were detected with low or no EpCAM expression (EpCAM-). Recovery of cells on microsieves depended strongly on cell size. One or more CTC were detected in 39% of the patient samples, this increased to 75% when adding the CTC detected in the discarded blood and to 82% with the use of additional cytokeratin antibodies. Presence of CTC was significantly associated with poor Overall Survival (OS) when detected by CellSearch without (p = 0.004) and with additional cytokeratins (p = 0.007), but not with EpCAM-CTC in the blood discarded by CellSearch (p = 0.271) or all CTC detected (p = 0.354) Conclusions: Expanding the cytokeratin coverage and including EpCAM-CTC, double the number of patients with CTC and the number of CTC detected with CellSearch. In contrast with EpCAM+ CTC, the presence of EpCAM-CTC in this group of patients was not associated with poor OS. The metastatic lung cancer patients included in this study were very diverse with respect to cancer type, line of therapy and quite small in numbers to make any definitive conclusions. Still, this pilot study warrants a larger study to confirm the findings. In addition an in-depth characterization of the EpCAM+ and EpCAM-CTC is needed to confirm that the EpCAM-, panCK+ CTC are indeed tumor cells and unravel the genetic difference with the EpCAM+, panCK+ CTC. Citation Format: Sanne de Wit, Guus van Dalum, Aufried T.M. Lenferink, Arjan G.J. Tibbe, Jeroen T.N. Hiltermann, Harry J.M. Groen, Cees van Rijn, Leon W.M.M. Terstappen. EpCAM+ and EpCAM- circulating tumor cells in metastatic lung cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 377. doi:10.1158/1538-7445.AM2015-377

Introduction: Circulating tumor cells (CTC) measured with the CellSearch system in patients with metastatic carcinomas are associated with poor survival. The frequency of CTC detected by the CellSearch system in non-small cell lung cancer (NSCLC) patients is relatively low, raising the question whether some CTC are not detected by the CellSearch system. To investigate this, additional antibodies were added to broaden the coverage of cytokeratins and leukocytes. Additionally, a device was designed that collects the sample material of the individual samples that are discarded by CellSearch. This collected waste is filtered for CTC isolation based on physical characteristics and the CTC are stained with a cocktail of antibodies. Methods: A device was designed that uses optical sensing to detect the presence of blood in the waste tube of the CellTracks Autoprep. It collects the waste of individual samples in a 50 mL conical tube. After collection the blood is passed with 100 mbar pressure through a 8x8 mm2 microfabricated silicon microsieve containing 300,000 pores of 5 µm in diameter (VyCAP, Deventer, The Netherlands). The performance was tested using four pre-stained cell lines: Colo320 (size 11 µm, ∼1,616 EpCAM antigens), SW480 (size 11 µm, ∼63,233 EpCAM antigens), T24 (size 16 µm, ∼2,167 EpCAM antigens) and SKBR3 (size 16 µm, ∼445,000 EpCAM antigens). Cells are spiked in 7.5 mL of blood collected in CellSave tubes from healthy volunteers. Spiked blood samples from healthy donors and patients with NCSLC and small cell lung cancer (SCLC) (enrollment is ongoing) were processed on the CellSearch and filtration system between 24 and 96 hours of collection. The cells on the microsieves were stained with a nucleic acid dye, antibodies recognizing leukocytes and all cytokeratins. Additional antibodies were added to the CellSearch test to cover all cytokeratins and broaden the coverage of leukocytes. Results: The recovery percentage of the CellSearch system for the different cell lines used was: 2% of COLO320, 91% of SW480, 2% of T24 and 87% of SKBR3. Additional recovery on the microsieves after filtration of the CellSearch waste was: 18% of COLO320, 6% of SW480, 59% of T24 and 2% of SKBR3. The combined recovery accounts for 20% of COLO320, 97% of SW480, 61% of T24 cells and 89% of SKBR3. In patients with NSCLC and SCLC either no CTC were detected at all, or in various proportions in the CellSearch cartridge, on the microsieves after filtration of the CellSearch waste or with the additional antibodies that were added. Conclusions: We combined the CellSearch system with a device for collecting and filtering the CellSearch waste. On cell lines this demonstrated that a low EpCAM expression results in the presence of CTC in the waste that would not be detected by the CellSearch system. In both NSCLC and SCLC additional CTC can be detected but it still remains to be determined whether the CTC not detected by the original CellSearch approach are also of clinical relevance. Citation Format: Sanne de Wit, Guus van Dalum, Joost van Dalum, Aufried Lenferink, Arjan Tibbe, Cees van Rijn, Jeroen Hiltermann, Harry Groen, Leon Terstappen. Circulating tumor cells in metastatic lung cancer enriched by EpCAM expression and physical characteristics. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4825. doi:10.1158/1538-7445.AM2014-4825