Desai, Aakash

Abstract Background: FGFR dysregulation is observed in multiple cancers and targeting FGFR is an emerging therapeutic strategy with FDA approved treatments in bladder and cholangiocarcinoma. Here we examined the prevalence of FGFR mutations, fusions, and high-level amplifications in breast cancer, stratified by receptor subtype and local/metastatic status, in both Foundation Medicine (FM) and institutional Mayo Clinic (MC) cohorts. Methods: For the FM cohort, comprehensive genomic profiling (CGP) examining at least 324 genes for all classes of alterations, including FGFR1-4 was carried out for 32,048 breast cancers during the course of routine clinical care in a Clinical Laboratory Improvement Amendments (CLIA)-certified lab (Foundation Medicine Inc., Cambridge, MA, USA). Tumor mutational burden (TMB) was determined on up to 1.1 Mb, microsatellite instability high (MSI-High) was determined on up to 114 loci and predicted ancestry from >10,000 SNPs. Estrogen receptor (ER) and HER2 status were available for a subset of FM samples. Additionally, 131 patients with metastatic breast cancer from a subset of patients at three Mayo Clinic sites (MC cohort) with clinical characteristics and cancer-panel DNA sequencing data from a CLIA-certified lab (Tempus, Chicago, IL) were included. Results: In the FM cohort, the prevalence of FGFR1-4 high-level amplification (CN≥10) was 10.1%, while mutations (1.5%) and fusions (0.72%) were rare. Most amplifications occurred in FGFR1 (9.2%); most fusions and mutations occurred in FGFR2 (0.46%, 0.77%). FGFR alteration prevalence was highest in ER+/HER2- subtype (14.4%) and lowest in HER2+ disease (7.7%). FGFR alterations were more common in IDC (11.7%) than ILC (7.7%), p<3E-08. FGFR alterations were more prevalent in the metastatic setting relative to breast-biopsied disease (13.6% v 10.1%; OR = 1.4; p=2E-17), especially in the HER2+ (OR =1.9, p=0.004) and ER-/HER2- (OR = 1.9, p = 0.05) disease; no enrichment was seen in the ER+/HER2- metastases (OR =1.0, p = 1). FGFR amplifications were observed at a higher prevalence in patients with predicted East Asian ancestry, relative to patients with European ancestry (12.1% v 10.0%; p = 0.03). Overall, the most common activating mutations in FGFR were FGFR2 N549K (n=85), FGFR1 N546K (n=78), FGFR4 V510M (n=28), FGFR2 K659E (n=28), FGFR4 V510L (n=20), and FGFR2 Y375C (n=15). The most common recurrent fusions were FGFR3:TACC3 (n=36), FGFR2:TACC2 (n=17), FGFR1:TACC1 (n=9), FGFR1:BAG4 (n=6), and FGFR2:ATE1 (n=5). In patients with FGFR amplifications, the most frequently co-occurring alterations were ZNF703 (78.4%), TP53 (51.5%), CCND1 (36.1%), FGF3/4/19 (32.9 - 34.4%), PIK3CA (30.7%), MYC (29.6%), ESR1 (17.2%), EMSY (16.3%), and PTEN (10.6%). Significant co-occurrence was observed for a number of genes including FGF3/4/19, CDK4, and CDK8 (all OR>2, p<1E-07); mutual exclusivity was observed with PIK3R1, BRCA1, and BRCA2 (all OR <0.5, p<4E-13), among other genes. In the 131 metastatic tumors from MC, the prevalence of FGFR1-4 high-level amplifications was 19.8% [FGFR1 (12.4%), FGFR2 (7.4%), and FGFR3 (0.8%)]. The prevalence of high-level FGFR amplifications did not differ by clinical subtypes: HR-/HER2- (7/31), HR+/HER2- (15/79), and HER2+ (2/11), p=0.68. Conclusions: High-level FGFR amplifications are observed in >11% of breast cancers, especially the ER+/HER2- subtype, while mutations/fusions are rare. These data support the ongoing studies evaluating targeted therapies for FGFR amplified ER + breast cancer. Correlations with clinical information (MC cohort) and associations with actionable alterations are ongoing and may inform potential combination strategies. Citation Format: Karthik V Giridhar, Ethan S Sokol, Peter T Vedell, Jason P Sinnwell, Aakash Desai, Tufia C Haddad, Ciara C O’Sullivan, Roberto A Leon-Ferre, Siddhartha Yadav, Kostandinos Sideras, Brenda Ernst, Minetta C Liu, Abe Eyman Casey, Xiaojia Tang, Zoe Fleischmann, Karthikeyan Murugesan, Krishna R Kalari, Matthew P Goetz. The frequency and somatic mutation landscape of Fibroblast growth factor receptor (FGFR) alterations in breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-08-02.

512 Background: The role of immune checkpoint inhibitors (ICIs) in the treatment of extrapulmonary neuroendocrine carcinoma (EP-NEC) has yet to be established. While objective responses have been observed, it is still unknown which patients are likely to derive benefit. We investigated the genomic profiles of patients who did and did not benefit from ICIs. Methods: Previously we reported the objective responses to ICI in a retrospective series of patients with EP-NEC. RECIST 1.1 criteria were used to categorize patients as achieving disease control (DC = CR, PR, or SD) vs progressive disease (PD). The EMR was reviewed to identify patients who had genomic panels performed, and results were extracted for analysis. Results: Of 31 patients eligible for RECIST assessment, 19 had genomic panels available (9 with DC: 4 SD, 5 PR vs 10 with PD). Of those with NEC histology specified, 9 were small cell, 1 combined large and small cell, 3 were large cell. All tumors were microsatellite-stable. All but one (with TMB = 25) of 16 tumors with TMB status available were < 10 m/MB. Of those with disease control, 67% had both TP53 and RB1 alterations, compared with only 10% in those with progressive disease; this was statistically significant ( p = 0.0198, Fisher exact). Of 7 tumors with TP53 + RB1 alterations, 4 were specified as small cell carcinoma. Half of those with PD showed alterations in β-catenin pathway genes CTNNB1 or APC, compared to only one of the DC group, but this did not reach significance ( p = 0.1409, Fisher exact). In an analysis of all Mayo patients (not just those treated with ICI) with NGS data available (Tempus and FoundationOne), concurrent TP53 + RB1 alteration was significantly more common in SCLC than in EP-NEC (Table). Conclusions: In this small series of patients with EP-NEC treated with ICIs, the SCLC-like genomic signature of concurrent TP53 + RB1 alterations was significantly more common in those with disease control than in those with progressive disease. An analysis of all patients with NGS data (not just on ICI) showed that the dual alteration was more common in SCLC, and SCLC also had more TMB-high tumors. This may explain why ICIs are more effective in SCLC than in EP-NEC. Further study is warranted to determine whether TP53 + RB1 mutations predict response to ICI in NEC.[Table: see text]

248 Background: Esophageal carcinoma is the 6th most common cause of death worldwide. While squamous cell carcinoma (SCC) was the most common among the histologic subtypes in the 20th century, recent reports have demonstrated an increased incidence of adenocarcinoma in both Eastern and Western world. With this changing paradigm of esophageal carcinoma, it is important to estimate the future burden of esophageal carcinoma by histology, age, sex, and race, that could help plan prevention, control, and treatment strategies for this cancer. Methods: We used Surveillance, Epidemiology, and End Results (SEER) 14 registries to obtain incidence data from 2000 to 2016. We applied age-period-cohort models to estimate future esophageal carcinoma incidence rates and the estimated disease burden by multiplying incidence forecasts by corresponding US Census population projections. Results: Our estimate suggests that the incidence (per 100,000 persons) of esophageal adenocarcinoma is increasing in people within the age group of 40-65 years. Our prediction showed that the incidence will increase from 2.12 in 2021 to 2.82 in 2030 (3.2% per year, 95% CI –2.3% to 9.1%, p=0.26). Notably, we noticed a similar marginal increase in incidence among Asians, Black, and Whites in the 40-65 years age group (3.1%, 3.2%, and 4.2%, per year, respectively). White males aged >65 years had the highest incidence of esophageal adenocarcinoma (17.34 in 2021), and incidence decreased 1.3% per year. We noticed a marginally decreased incidence in Black male (-1.1% per year, p=0.71) and Asian male (-3.9% per year, p=0.17) population aged >65 years. Interestingly, we found a decrease in the incidence of SCC in the current age groups 40-65 (-2.7% per year, p=0.31) and >65 years (-4.6% per year, p=0.081). We observed that Asians had the greatest decrease in incidence (-4.3% per year) as compared to that of Blacks (-4.2% per year) and Whites (-2.9% per year), although there was no statistically significant difference in the annual decrease among races. Conclusions: In our study of esophageal cancer, we predict an increased incidence of adenocarcinoma histology subtype in the younger age group (40-65 years) while the SCC subtype will have a decreased trend. Strategies to prevention esophageal adenocarcinoma, including dietary changes, should preferentially target patients <65 years of age.[Table: see text]

Abstract Background: Despite the promise of targeted agents in hematology, the high price of cancer therapies is a rapidly evolving problem. Until now, the increase in price of targeted anti-cancer treatments used in common hematological malignancies has not been evaluated. Here, we report patterns in price changes from 2015-2019 for multiple in-class anticancer medications for common hematologic malignancies. Methods: We utilized the publicly available Medicare Part D provider utilization and payment database from 2015 to 2019. We extracted drug prices (using generic names) for commonly used targeted anticancer agents for acute myeloid leukemia, chronic myeloid leukemia, chronic lymphocytic leukemia, B-cell lymphomas, and multiple myeloma. The primary outcome was the correlation of average change in Medicare spending per dosage unit among the multiple brand-name medications within each class available. We additionally calculated compound annual growth rates (CAGRs) [i.e. mean annual growth rates over a specified period of time] for medication costs within each class, and compared it with the consumer price index (CPI) (a measure of the average change over time in the prices of consumer items) and inflation rate. Agents without in-class competitor were excluded. CPI and inflation rates came from U.S. Bureau of Labor Statistics. Results: The study included 6 BCR-ABL inhibitors (1 generic), 2 BTK inhibitors, 2 IDH inhibitors, 2 FLT3 inhibitors, 3 IMIDs, 3 PI, 2 PI3K inhibitors, and 5 anti-CD20 monoclonal antibodies. The median (range) Pearson correlation coefficient values for drugs within each class were -0.155 (-0.984-0.992) for BCR-ABLi, -0.362 for BTKi, 0.234 (0.215-0.999) for IMIDs, 0.899 (-0.034-0.988) for PIs, and 0.954 (0.847-0.999) for anti-CD20 antibodies. The median correlation coefficient for BCR-ABLi was 0.751 if generic imatinib was excluded. The correlation coefficient between 2 nd and 3 rd generation IMIDs was 0.999. Non-generic BCR-ABLi and anti-CD20 antibodies showed strong linear association in price increase between two drugs within the same class. Due to drug novelty, coefficient could not be calculated for therapies with 2 or fewer data points (midostaurin, gilteritinib, enasidenib, ivosidenib, idelalisib, duvelisib). There was no significant correlation between expenditure for BTKi, PIs, and IMIDs. The median CAGRs in costs over this 5-year period were: were 6.29% for BCR-ABLi, 18.36% for BTKi, 2.69% for IDHi, 4.23% for FLT3i, 10.63% for IMIDs, 5.11% for PIs, 5.79% for PI3Ki, and 5.85% for anti-CD20s. The median CAGR in costs for modern precision-driven cancer therapeutic classes outpaced CPI (2.26%/year), and the average inflation rate (1.90%/year). Conclusions: Increase in cost within the same class should be weighed against incremental clinical benefit for the patients. For non-generic BCR-ABLi and anti-CD20 antibodies, despite there being several agents, the rise in drug expenditures correlated closely, calling into question the true value of within-class competition. There is an urgent need for drug pricing reform given the average expenditure of Medicare part D, and ultimately out-of-pocket costs for our patients with cancer continues to trend upwards. Increased advocacy efforts are needed to ensure precision therapeutics remains an attainable and sustainable goal. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

7 Background: Despite the promise of precision oncology, the cost-effectiveness of targeted treatments is debated. Until now, the increase in price of oral targeted anti-cancer treatments used in common malignancies has not been evaluated. Here, we report patterns in price changes from 2015-2019 for multiple oral anti-cancer medications for common solid tumor malignancies. Methods: We utilized the publicly available Medicare Part D provider utilization and payment database from 2015 to 2019. We extracted drug prices (using generic names) for commonly used targeted oral anticancer agents for lung, breast, and prostate cancer. The primary outcome was the correlation of average change in Medicare spending per dosage unit among the multiple brand-name medications within each class available. We additionally calculated compound annual growth rates (CAGRs) [i.e. mean annual growth rates over a specified period of time] for medication costs within each class, and compared it with the consumer price index (a measure of the average change over time in the prices of consumer items). Results: The study included 6 EGFR inhibitors (1 generic), 5 ALK inhibitors, 2 BRAF inhibitors, 3 hormonal agents (1 generic), 3 CDK4/6 inhibitors, 2 PARP inhibitors, and 7 anti-androgen agents (2 generic). The median (range) Pearson correlation coefficient values for drugs within each class were 0.967 (0.915-0.978) for EGFRi, 0.981 (0.966-0.989) for ALKi, 0.996 for BRAFi, 0.994 (0.992-0.999) for CDK4/6i, 0.855 for PARPi, and 0.442 (-0.522-0.962) for anti-androgens. Except for anti-androgens, all other drug classes showed strong linear association in price increase between two drugs within the same-class. A coefficient could not be calculated for therapies with 2 or fewer data points ( i.e., generic erlotinib, dacomitinib, generic abiraterone, apalutamide, and darolutamide). There was no significant correlation between expenditure for anti-estrogen agents. The median (range) CAGRs in costs over this 5-year period were: were 4.56% for EGFRi, 6.40% for ALKi, 2.58% for BRAFi, 5.48% for hormonal agents, 5.21% for CDK4/6i, 27.29% for PARPi, and 34.8% for anti-androgen agents. Conclusions: The median CAGR in costs for modern oral precision driven cancer therapeutic classes mostly outpaced CPI (2.26%/year), and the average inflation rate (1.90%/year). Increase in cost within the same class should be weighed against incremental clinical benefit for the patients. For most classes despite there being multiple agents, the rise in drug expenditures correlated closely, calling into question the true value of within class competition. There is an urgent need for drug pricing reform given the average expenditure of Medicare part D, and ultimately out of pocket costs for our patients with cancer continues to trend upwards. Increased advocacy efforts are needed to ensure precision therapeutics remains an attainable and sustainable goal.

135 Background: Black patients have a disproportionately high incidence and mortality from lung cancer. Despite the importance of clinical trials, there continue to be significant racial disparities in recruitment for pivotal registration studies. In 2016, the FDA recommended reporting racial enrollment with a minimum of 5 categories (White, Black, Asian, American Indian or Alaskan Native [AIAN] and Native Hawaiian or Pacific Islander [NHPI]). The International Committee of Medical Journal Editors also recommend reporting race and ethnicity. We evaluated race reporting and representation in registration trials for thoracic cancers. Methods: We reviewed the FDA website and identified all new drug licensing indications in thoracic malignancies (small cell lung cancer (SCLC), non-small cell lung cancer (NSCLC) and mesothelioma) from 2006 to 2020. NSCLC was further classified as EGFR+, ALK+, other mutation and NOS (no driver mutation). Clinical trials cited on the licensing label for market authorization were recorded and the corresponding registration trial publication was identified. If race was unreported or underreported (defined as ≤3 groups) in the licensing study, then additional information was obtained from clinicaltrials.gov. We calculated the proportion of registration trials meeting FDA criteria and the proportion of each racial group in trials. Results: From 2006-2020, we identified 55 new licensing indications, involving 26 unique drugs; 5 approvals in SCLC, 49 approvals in NSCLC and 1 in mesothelioma. Prior to the FDA race reporting guidelines, 33% (6/18) of registration studies did not meet FDA requirements. This improved to 27% (10/37) after the guideline introduction. Overall 29,545 patients participated in thoracic registration trials; 66% White, 22% Asian, 2% Black, <1% AIAN, <1% NHPI, 1% other or multiple races and 9% unknown. Table shows race distribution by cancer subtype. Conclusions: Although improving, a substantial number of registrational clinical trials in thoracic oncology still do not report race per FDA guidance. In addition, Black individuals are disproportionately under-represented in registration trials. Greater efforts are needed for the inclusion of Black patients and other minorities in clinical trials.[Table: see text]

AbstractActivating receptor-tyrosine kinase rearranged during transfection (RET) mutations and fusions are potent drivers of oncogenesis. The recent FDA approvals of highly potent and selective RET inhibitors, selpercatinib and pralsetinib, has altered the therapeutic management of RET aberrant tumors. There is ample evidence of the role of RET signaling in certain cancers. RET aberrations as fusions or mutations occur in multiple cancers, however, there is considerable phenotypic diversity. There is emerging data on the lack of responsiveness of immunotherapy in RET-altered cancers. Herein, we review the registrational data from the selective RET-inhibitor trials, and comprehensively explore RET alterations in pan-cancer adult malignancies and their co-alterations. These co-occuring alterations may define the future of RET inhibition from specific selective targeting to customized combination therapies as data are rapidly emerging on both on-target and off-target acquired resistance mechanisms. Fascinatingly, oncogenic RET fusions have been reported to mediate resistance to EGFR inhibition and KRASG12C inhibition.