Stage IV

Three independent principal investigators at the Fred Hutchinson Cancer Research Center with combined expertise in thoracic oncology, cancer epidemiology and prevention, and molecular diagnostics are joining efforts to respond to the Protect Your Lungs RFA. The proposed research program is focused on developing novel blood-based tests to 1) identify never-smoker subjects at increased risk of developing lung cancer (C. Li, PI), 2) detect lung cancer before onset of symptoms (G. Goodman, PI),  and 3) distinguish between benign and malignant lesions identified by CT scans (S. Hanash, PI). The research questions address important public health issues in lung cancer and build on discoveries of candidate markers by the applicant group for which we propose validation studies in this proposal. Validation studies to be conducted will take advantage of the availability to the investigators of pertinent bio-specimens consisting of samples derived from two large cohort studies (The Women’s Health Initiative and the Beta Carotene and Retinol Efficacy Trial (CARET)) and samples derived from CT screening studies. The samples available are sufficient to meet the needs of the proposed studies. The collaborative nature of the proposed research will ensure synergism and efficiency of scale to meet study objectives and fast-track the development of clinically relevant applications.

Folate/homocysteine (Hcy) metabolism facilitates the methylation of DNA, proteins and carcinogens; nucleic acid synthesis; and glutathione generation. Dysregulation of folate/Hcy metabolism, due to suboptimal vitamin status and/or functional polymorphisms of key enzymes, is an etiologic feature of some cancers, including lung cancer. Several drugs that target enzymes of folate/Hcy metabolism have become mainstays of cancer chemotherapy, most recently pemetrexed (PMX), which targets dihydrofolate reductase (DHFR) and thymidylate synthase (TS) and is used to treat patients with non-small cell lung cancer (NSCLC). Our primary and secondary hypotheses are that folate/Hcy phenotype, perhaps underpinned by genotype, is a major contributor to (i) clinical response to PMX, and (ii) risk of NSCLC itself. We will use archived and newly acquired samples from PMX-treated NSCLC patients to define pre-treatment and in-treatment folate/Hcy phenotypes using LC-MRM/MS technology that can precisely determine the concentrations and relative proportions of key folates (tetrahydrofolate; 5-methyltetrahydrofolate; 5,10-methenyltetrahydrofolate) and Hcy. Genotypes will be determined for approximately twenty folate-related genes. Biostatistical analyses will be used to establish

whether aspects of folate/Hcy phenotype and/or genotype are prospectively or concurrently associated with time to tumor progression, survival time, toxicity, etc. Case-control analysis of genetic and phenotypic data will also be undertaken to determine whether any genetic and/or biomarker variables predict case status. This project has the potential to identify biomarkers and/or genetic factors that can be used to predict or monitor responses of NSCLC patients to PMX, and may provide the basis for the future deployment of personalized medicine strategies in lung cancer treatment.

Melanoma has the highest propensity to metastasize to the brain once the disease has spread, while non-small cell lung cancer (NSCLC) has the highest incidence of brain metastases among all cancers. Approximately 50,000 patients develop brain metastases from these diseases every year. Patients with brain metastases have exceedingly limited therapeutic options since they are typically excluded from clinical trials. Recently a number of new systemic immune therapies, such as nivolumab (BMS-936558) and lambrolizumab (MK-3475), two inhibitors of PD-1 (an immune inhibitory molecule), have led to dramatic responses in metastatic melanoma (MM) and NSCLC. However, these therapies have not been studied in patients with untreated brain metastases.  Little is known about immune cells in the brain, and whether the immune system can be stimulated to reject cancer cells. Moreover, little is known about what tumor characteristics are associated with response to MK-3475 in brain metastases. This proposal includes innovative correlative biomarker studies incorporated into a clinical trial uniquely designed to study the activity of MK-3475 in patients with limited, small brain metastases in MM and NSCLC. This drug carries the hope to provide prolonged responses similar to responses seen in other metastatic sites, and might enable patients to avoid radiation therapy, and improve their outcome. As part of this clinical trial, we will collect brain and other metastatic specimens from patients enrolled and study the expression of immune inhibitory molecules utilizing a novel quantitative assay and algorithms that we have developed in preliminary work. These studies will facilitate selection of patients who are more likely to respond to this class of drugs.

Advanced (stage IV) lung adenocarcinoma is an incurable disease. Treatment mostly consists of chemotherapy, which provides a consistent but small survival benefit. Standard therapy includes a platinum-doublet (pemetrexed or paclitaxel) often in combination with bevacizumab, followed by maintenance bevacizumab or pemetrexed. Programmed death 1 (PD-1) is a T-cell surface receptor that when activated, delivers a negative signal to T cells. This feedback mechanism dampens immune responses when no longer needed, preventing damaging autoimmune reactions. Tumors can co-opt this T-cell control mechanism to escape surveillance and/or rejection by the immune system. Thus, reversing this tumor action can result in antitumor activity worthy of clinical evaluation. Recently it has been demonstrated that inhibition of the PD-1 receptor with an anti-PD-1 monoclonal antibody (nivolumab) has significant clinical activity in lung cancer with an ORR of 26%. As remarkable as this may be, given the heavily pretreated population of lung cancer patients studied, this also indicates that 74% of patients did not respond and remained resistant to this approach. Therefore, going forward it is important to develop combination therapies to improve the efficacy of this approach, and to discover resistance mechanisms that may allow for better patient (and tumor) selection. One potential class of agents to be used in combination with anti-PD-1 is the adenosine A2AR antagonists. Given that A2AR on T cells within the tumor microenvironment contributes to immune escape and therapeutic resistance, the addition of PBF-509 is expected to improve the efficacy of nivolumab.

Better methods are required to accurately risk stratify patients with a solitary pulmonary nodule (SPN) who may undergo unnecessary procedures to exclude a cancer diagnosis. 18F-FDG Positron Emission Tomography (PET) is a widely available clinical test used to evaluate concerning SPNs and stage malignant lung nodules. It therefore facilitates clinical assessment but remains an imperfect tool for the diagnosis, localization, and prognostication of SPNs, be they infectious or malignant in nature. Furthermore, it performs well for staging lung cancer, but inaccurately categorizes patients in some cases who receive futile thoracotomies for disseminated disease, or conversely, are undertreated for localized disease. The applicant therefore plans on investigating whether circulating molecular biomarkers can increase the utility of 18F-FDG-PET imaging in clinical practice using statistical models that incorporate in vivo and in vitro diagnostics The concept here is “one-stop shopping,” where a patient can obtain routine molecular imaging and molecular diagnostics from routine blood work during an appointment that in combination increase the accuracy of a clinician’s diagnosis and facilitate the appropriate decision-making process. For this proposal we will develop a model that incorporates a circulating microRNA profile to discriminate infectious from malignant SPNs for patients along with clinical and FDG-PET data and, secondly, identify patients with malignant nodules and detectable circulating tumor cells to determine whether these cells upstage or augment clinical staging or prognosis post-operatively when compared to FDG-PET alone.

The genotype-directed use of EGFR TKIs in EGFR-mutant lung cancer patients has fundamentally changed the face of the disease with improved response to therapy, preserved quality of life, and prolonged progression-free survival. However, tumors that initially respond become resistant after ~ 1 year (i.e., acquired resistance, AR). The biology of AR is incompletely understood and is largely inferred from pre-clinical models. Our group at Mass General implemented a wide-scale program to perform repeat biopsies on EGFR-mutant patients with AR to first-generation EGFR inhibitors (gefitinib, erlotinib). This translational research paradigm has been instrumental in gaining insight into AR and has led to novel observations such as PIK3CA and BRAF mutations as mechanisms of AR and the abundant frequency of phenotypic changes at the time of AR like small cell lung cancer and epithelial-to-mesenchymal transitions. The repeat biopsy results have directly helped our patients as well, by informing choices about the most relevant clinical trials or alternative treatments. Currently, a new cohort of EGFR TKIs is entering the clinic: 2^nd-generation irreversible pan-HER inhibitors and 3^rd-generation T790M-specific inhibitors. Little is known about how AR develops to these newer therapies or how the biology of EGFR-mutant cancers evolves over time after exposure to sequential EGFR blockers.

Our proposal aims to discover the mechanisms of AR to next-generation EGFR TKIs and to understand the evolution of EGFR-mutant cancers as they face the selective pressure of sequential types of EGFR-directed therapies. To accomplish this we will collaborate across institutions to amass a large number of pre-treatment and post-treatment paired patient biopsies which we will interrogate via allele-specific genotyping as well as whole genome sequencing to define mechanisms of AR. In addition we will utilize an innovative technique of taking tumor tissue directly from a biopsy and deriving patient-specific in vitro and in vivo models in the laboratory. Expansion of these models will yield a larger supply of AR cancer material to aid descriptive and functional research about the biology of AR. In addition, establishment of pre-treatment patient-specific models will allow us to verify whether the mechanism of AR derived in the lab through ex-vivo therapy mirrors the eventual clinical mode of AR.