Konstantinos Leventakos

S768I Mutation in EGFR in Patients with Lung Cancer

Introduction: Epidermal growth factor receptor gene (EGFR) mutations are relatively common oncogenic drivers in non–small cell lung cancer (NSCLC). The outcomes of patients who present with less common EGFR mutations or more than one EGFR mutation are uncertain. We reviewed our experience with the S768I mutation of exon 20 of EGFR to provide insight into the clinical significance of this mutation. Methods: We used a natural language search program to search our electronic medical record system and every EGFR mutation analysis of patients with NSCLC treated at Mayo Clinic that was performed in our Department of Molecular Genetics to identify patients with EGFR S768I mutation. Relevant clinical and laboratory data were abstracted for selected cases, including evaluation of response after treatment with tyrosine kinase inhibitors. Results: A total of 1527 patients with NSCLC who underwent EGFR testing were reviewed. The S768I mutation was present in nine patients (0.59%), four of whom were female. Only three had an isolated S768I mutation, four had a concurrent G719 mutation, and two had a concurrent L858R mutation. Among patients with stage IV disease treated with erlotinib (n = 4), one had an isolated S768I mutation and three had additional mutations (two patients with G719 and one patient with L858R). The tumor response to erlotinib of patients with stage IV disease was highly variable (progression‐free survival ranged from 3 to 30 months and overall survival ranged from 5 to more than 51 months). Conclusions: S768I mutations in exon 20 of the EGFR gene are rare and are typically seen in conjunction with sensitizing EGFR mutations. Because of this mutations rarity and the variability of responses of treated cases, its exact prognostic and predictive role is not fully understood. In our experience, S768I mutations in isolation do not necessarily confer sensitivity to erlotinib, but in conjunction with sensitizing EGFR mutations, S768I mutations do not restrict efficacy.

Reflections on immune checkpoint inhibition in non-small cell lung cancer.

Despite the expanding armamentarium of treatment modalities against metastatic non-small cell lung cancer (NSCLC) this disease remains incurable. The introduction of targeted therapies provides transient control of disease for some molecular subtypes but virtually all patients’ progress. Recently immunotherapies have been approved for the treatment of metastatic melanoma and prostate cancer, and have shown promise for the treatment of NSCLC. More specifically, the blockade of immune checkpoints may improve outcomes in the treatment of NSCLC. Immune checkpoints modulate immune responses to effectively balance self-tolerance and tissue destruction. Many tumors express immune checkpoints or their ligands to inhibit anti-tumor immune responses. One of the most important immune checkpoints is programmed cell death ligand 1 (PD-L1), which was discovered at Mayo Clinic (1).

Management of multifocal lung cancer: Results of a survey.

Introduction: Multifocal lung cancer is an increasingly common clinical scenario, but there is lack of high‐level evidence for its optimal treatment. Thus, we surveyed members of the interdisciplinary International Association for the Study of Lung Cancer on their therapeutic approaches and analyzed the resultant practice patterns. Methods: We described the clinical scenario of an otherwise healthy 60‐year‐old man with bilateral pulmonary nodules and asked the 6373 members of the International Association for the Study of Lung Cancer whether they would recommend surgery, and if so, the extent of surgery. We also asked what other measures would be recommended to complete the staging and whether radiation therapy or chemotherapy would be suggested. Results: We received 221 responses (response rate 3.5%) from multiple specialists. Most respondents (140 [63%]) recommended surgery for this scenario. Surgeons were significantly more likely to recommend surgery than were those in other specialties. Of those who recommended surgery, most would obtain a PET/CT scan to rule out distant metastases and a magnetic resonance imaging scan to rule out brain metastases; but in the absence of radiographic lymph node involvement, most would not stage the mediastinum by bronchoscopy or mediastinoscopy before resection. When surgery was not recommended or declined, respondents commonly recommended radiation. Conclusions: This survey suggests that therapeutic recommendations for multifocal lung cancer are influenced to a large extent by physicians’ specialty training, probably because of the lack of high‐level evidence for its standard treatment. Ongoing systematic and multidisciplinary approaches with robust short‐term and long‐term patient outcomes may improve the quality of evidence for the optimal management of this clinical entity.

Abstract 3093: Expression of DLL3 in metastatic melanoma, glioblastoma and high-grade extrapulmonary neuroendocrine carcinomas as potential indications for rovalpituzumab tesirine (Rova-T; SC16LD6.5), a delta-like protein 3 (DLL3)-targeted antibody drug conjugate (ADC)

Expression of DLL3 was examined in additional tumor types, as it was found to be highly expressed in tumor-initiating cells (TIC) in small cell lung cancer (SCLC), where a DLL3-targeted antibody drug conjugate (ADC), rovalpituzumab tesirine (Rova-T; SC16LD6.5; Saunders et al. 2015 Sci Transl Med 7:302ra136)) exerted clinically meaningful anti-tumor effects in a phase I trial (Spigel et al. 2016 Lancet Oncology; In Press). DLL3 expression was profiled by qRT-PCR, ELISA and immunohistochemistry in multiple tumor types. Patient-derived xenografts (PDX) from melanoma and ovarian small cell carcinoma were established and used for efficacy studies to determine the ability of Rova-T to impact tumor growth and TIC frequency. DLL3 expression was seen in metastatic melanoma (55%), low grade gliomas (90%), glioblastoma (70%), medullary thyroid cancer (65%), carcinoids (33%), dispersed neuroendocrine tumors in the pancreas (9%), bladder (57%) and prostate (24%), testicular cancer (90%), and lung adenocarcinomas with neuroendocrine features (80%). Unlike SCLC, where DLL3 does not predict clinical outcome on standard therapies, DLL3 expression negatively correlates with overall survival in melanoma and small cell bladder cancer. In mice bearing DLL3 positive melanoma PDX, treatment with a single dose of Rova-T resulted in effective and durable responses (>100 days), which correlated with a significant impact on TIC frequency. Similarly, in mice bearing DLL3-positive ovarian small cell PDX, a single dose of Rova-T resulted in effective and durable responses (>100 days). Our results show that DLL3 is expressed in many neuroendocrine tumors (lung, ovarian, prostate, bladder, etc), metastatic melanoma, medullary thyroid cancer, low-grade gliomas and glioblastoma. Given pre-clinical results showing efficacy of Rova-T in melanoma and ovarian small cell carcinoma, as well as encouraging clinical data with Rova-T in patients with recurrent/refractory SCLC, clinical evaluation of Rova-T in DLL3-positive melanoma, glioblastoma, medullary thyroid cancer and other high-grade neuroendocrine carcinomas is warranted. A “basket” trial enrolling patients with DLL3-positive solid tumors is now recruiting patients (NCT02709889). Citation Format: Laura R. Saunders, Samuel A. Williams, Sheila Bheddah, Kumiko Isse, Sarah Fong, Marybeth A. Pysz, Himisha Beltran, Loredana Puca, Verena Sailer, Juan M. Mosquera, Yu Yin, Jiaoti Huang, Andrew J. Armstrong, Jorge Garcia, Cristina Magi-Galluzzi, Vadim Koshkin, Petros Grivas, Farhad Kosari, John Cheville, Justin C. Moser, Thomas J. Flotte, Thorvardur Halfdanarson, Aaron Mansfield, Konstantinos N. Leventakos, Julian R. Molina, Douglas W. Ball, Barry D. Nelkin, Jill E. Shea, Courtney L. Scaife, Scott J. Dylla. Expression of DLL3 in metastatic melanoma, glioblastoma and high-grade extrapulmonary neuroendocrine carcinomas as potential indications for rovalpituzumab tesirine (Rova-T; SC16LD6.5), a delta-like protein 3 (DLL3)-targeted antibody drug conjugate (ADC) [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 3093. doi:10.1158/1538-7445.AM2017-3093

88P: Use of brain imaging in the management of patients with lymph node negative multifocal lung cancer.

Y.S. Kim1, S.H. Yoon1, B.S. Son2, D.H. Kim2, K. Kim3, I.-J. Kim4. 1 Pulmonology, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea, 2 Thoracic surgery, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea, 3 Nuclear Medicine, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea, 4 Internal Medicine, Pusan National University Hospital, Busan, Republic of Korea

Abstract 4513: A prognostic model for pulmonary carcinoid tumors based on large chromosomal alterations

PURPOSE: Previous mutational analyses have failed to identify a predictive or prognostic marker for pulmonary carcinoid tumors (PCT). The heterogeneity of PCTs coupled with a lack of detailed information about the tumor biology, impedes patient stratification into groups based on tumor phenotypes or treatment response. We sought to use high-throughput next-generation sequencing to improve prognostication. METHODS: We stratified 37 patients with resected PCTs as low risk (n = 17) and high risk (n = 20) based on a 5 year long follow up for recurrence. Patients with no recurrence within 5 years from initial treatment were deemed low risk. Macrodissection was followed by genomic DNA isolation and next-generation sequencing was performed using an Illumina Mate Pair library protocol. Sequence reads were mapped to the human genome, and primers spanning the fusion junctions were used for validation polymerase chain reaction. RESULTS: Carcinoids commonly harbor rearrangements (median 3.5, range 1-167). Large chromosomal gains or losses were found in 24 of the cases (64.8%). We developed a prognostic score that included the total amount of genetic alterations (deletions and translocations). ROC analysis revealed an AUC of 0.76. High risk patients had a mean score of 20 and low risk patients had a mean score of 5.45 (p value = 0.03, Welch Two Sample t-test). Further analysis of the specific genetic alterations harbored by high and low risk PCTs and correlation with the pathologic and immunohistochemical information is currently underway. CONCLUSION: Large chromosomal rearrangements and aneuploidy portend a poor prognosis for patients with PCTs. Mate Pair sequencing of PCTs provides valuable prognostic information for this highly heterogeneous group of cancers. Citation Format: Konstantinos Leventakos, Aaron S. Mansfield, Stephen J. Murphy, Sarah H. Johnson, Sarah E. Kerr, Marie Christine Aubry, George Vasmatzis, Julian R. Molina. A prognostic model for pulmonary carcinoid tumors based on large chromosomal alterations. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4513.

Significance of Immune Checkpoints in Lung Cancer

The treatment landscape for lung cancer is quickly evolving and has been driven by both immunotherapy and targeted therapy. Tremendous, durable responses to immunotherapy that inhibits PD-1 or PD-L1 have been observed in patients with lung cancer; however, significant confusion exists over how to select patients to receive immunotherapy as the majority of patients receive no benefit from it. The number of companion or complementary assays for PD-L1, the different staining patterns of these assays, the agreement of PD-L1 detection between these assays, and the intra- and intertumoral heterogeneity of PD-L1 expression further obfuscates patient selection. Other biomarkers such as tumor mutation burden measured by next-generation sequencing, or blood-based biomarkers, are starting to show some benefit in patient selection. Many clinical trials are evaluating immunotherapy in earlier stages of disease, and in various sequences or combinations in attempts to improve responses and survival. These studies, and the associated correlative work to improve patient selection, may further change how we treat lung cancer in the near future.

Abstract A26: Representation of minorities, the elderly, and women in over 1000 clinical trials

Background: Despite the importance of diversity while studying new drugs, many cancer clinical trials (CT) lack appropriate representation of specific patient populations, limiting the generalizability of the evidence obtained. Therefore, we determined the representation of ethnic minorities, the elderly, and women in cancer CT. Methods: Enrollment data from all therapeutic trials reported as completed in clinicaltrial.gov from 2003 to 2016 were analyzed. CT in rare cancers ( Results: Out of 1,012 CT, 310 (31%) reported ethnicity with a total of 55,689 enrollees. 46,431 (83%) enrollees were non-Hispanic white, 3,270 (6%) African American, 2,982 (5.3%) Asian, 1,484 (2.6%) Hispanic, and 1,332 (2.4%) were classified as other. Participation in CT varied significantly across ethnic groups; non-Hispanic whites were more likely to be enrolled in CT (EF of 1.2%) than African Americans (EF of 0.7%, p Conclusions: African Americans, Hispanics, and the elderly were less likely to be enrolled in CT. Comparing with historical data, we observed a decrease in minorities9 recruitment over the past 14 years. This change could be attributed to the increased complexity of CT and mandatory molecular testing as many minorities lack access to institutions with genetic-testing capacity. Future trials should take extra measures to recruit participants who adequately represent the U.S. cancer population. Citation Format: Narjust Duma, Jesus Vera-Aguilera, Yucai Wang, Jonas Paludo, Konstantinos Leventakos, Aaron Mansfield, Alex Adjei. Representation of minorities, the elderly, and women in over 1000 clinical trials [abstract]. In: Proceedings of the Tenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2017 Sep 25-28; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2018;27(7 Suppl):Abstract nr A26.

Abstract A34: Targeting genes which are amplified in ovarian cancer

Over the recent years significant knowledge has been accumulated on which drugs can be therapeutically beneficial for a given patient based on mutational profiling of their tumors using selected gene panels. Much less, however, is known under which conditions targeting of genes which are amplified could be beneficial. Apart from successfully targeting HER2-positive cancers, many of which frequently carry amplified ERBB2 gene, no other targeted therapy based on DNA amplifications or gains of the genes is offered to the patients due to lack of clinical response data. Using mate pair sequencing we have profiled 60 high grade serous ovarian tumors to compare genomic rearrangements and copy number changes. The analyses revealed that these tumors carry highly rearranged genome. Copy number changes amplifications, gains and losses were very common and included genes potentially therapeutically targetable. In contrast, only a few of targetable fusion genes were identified in a set of 60 cases. The tumors were propagated in immunocompromised mice (mouse avatars), sequenced and showed identical to original patient tumor landscape of rearrangements. Using these mouse avatar models we tested whether a therapy inhibiting selected based on genomic amplification targets provided a benefit compared to standard chemotherapy. Mice which harbored tumors showing amplifications of CDKs (CDK2, 4 and 9) and ERBB3 were treated with flavopiridol and pertuzumab respectively, and response was compared to that of standard for ovarian cancer chemotherapy (carboplatin and paclitaxel combination). We observed that application of either agent, significantly inhibited tumor growth in treated mice as compared to untreated. However, neither drug alone caused tumor regression. The treatment regimen then was modified to administer chemotherapy and targeted therapy together. A mouse avatars in which genomic analyses revealed amplification at loci involving AKT3 and RICTOR genes was treated with chemotherapy alone and in combination with MK2206 (AKT inhibitor) or MK8669 (mTOR inhibitor). The high level of both target proteins was confirmed by immunoblotting. Significant regression of tumor was observed after 6 weeks of treatment. Addition of either targeted drug provided an extra benefit in killing tumor cells compared to chemotherapy alone. The mice are followed to study tumor recurrence. These data indicated that genomic information obtained using next generation sequencing can aid therapy decisions by tailoring treatments to individual tumor makeup. Avatar models in conjunction with genomic analyses of the original tumors are invaluable for testing specific targeted therapies selected based on amplification/gains of putative genes-targets and for studying mechanisms of tumor recurrence and therapy resistance. Citation Format: Faye R. Harris, Lin Yang, Xiaonan Hou, Konstantinos Leventakos, Saravut J. Weroha, George Vasmatzis, Irina V. Kovtun. Targeting genes which are amplified in ovarian cancer. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Targeting the Vulnerabilities of Cancer; May 16-19, 2016; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(1_Suppl):Abstract nr A34.