Demographic Disparities in Acute Myeloid Leukemia Mortality Trends in the United States

BACKGROUND/AIM

Acute myeloid leukemia (AML) is a hematological malignancy with an overall poor prognosis; however, survival rates vary widely by clinical and demographic characteristics. This study sought to identify historical trends in AML mortality in the US and to identify any disparities by sex, race or ethnicity.

PATIENTS AND METHODS

For each demographic population, the age adjusted mortality rate (AAMR) per 1,000,000 for AML-related deaths from 1999 to 2020 in the United States was accessed from the CDC Wonder Database. These values were then used to calculate the average Annual Percent Change (AAPC) from 1999 to 2020 using the National Cancer Institute (NCI)'s Joinpoint Regression Program (Joinpoint V 4.9.0.0, NCI) with log-linear regression models. Statistical significance for all reported findings was determined using a 2-tailed t-test or parallel pairwise comparison with significance defined as p<0.05.

RESULTS

The overall population had a significant downtrend in mortality rate between 2011 and 2020 with an APC of -0.61% [95% confidence interval (CI)=-1 to -0.2]. In 2020, the AAMR due to AML for males was 32 and for females was 20.2. Females did not have a significant overall AAPC from 1999 to 2020. Males had a significant AAPC of 0.5% (95%CI=0-0.9) from 1999 to 2020, signifying an overall uptrend. In 2020, the White population had the greatest mortality rate (29.6), followed by the Black or African American population (20.9), Asian or Pacific Islander (AAPI) population (18.6), and the American Indian/Alaska Native population (8.8). American Indian and Alaska Native population data could not be reliably compared. No race/ethnic group had a significant AAPC trend from 1999 to 2020. However, parallel pairwise comparison found a significant difference in the trend of mortality rates between the Black or African American and AAPI, Black or African American and White, and White and AAPI populations.

CONCLUSION

Our findings highlight disparities in mortality due to AML and underscore the need for additional resources and support in affected populations and areas.

Demographic disparities in trend of gynecological cancer in the United States

PURPOSE

This study aimed to analyze the age-adjusted mortality rates (AAMR) per 100,000 for gynecological cancer-related deaths in the United States from 1999 to 2020. We compare trends by different demographic groups to identify significant disparities in these rates between populations within the United States.

METHODS

The National Cancer Institute's Joinpoint Regression Program was used to calculate the average Annual Percent Change (AAPC) to identify trends over the study period using data from the CDC Wonder database, which comprises of demographic information for all causes of mortality in the United States from death certificate records.

RESULTS

From 1999 to 2020, the African American population exhibited a significant downtrend (AAPC, -0.8% [95% CI, - 1.0% to - 0.6%]; p < 0.01), while the white population also demonstrated a notable downtrend (AAPC, - 1.0% [95% CI, - 1.2% to - 0.8%]; p < 0.01). Similarly, the AI/AN population experienced a decline (AAPC, - 1.6% [95% CI, - 2.4% to - 0.9%]; p < 0.01). The AAPI population did not observe a significant trend (AAPC, - 0.2% [95% CI, - 0.5% to 0.5%]; p = 0.127). In addition, the Hispanic/LatinX population experiencing a lower rate of decline compared to non-Hispanics (p = 0.025).

CONCLUSIONS

We found that the AI/AN population to observe the greatest downtrend in mortality rates, while the AAPI observed the least and that the African American population observed a smaller downtrend when compared to the white population. In addition, the Hispanic/LatinX community are significantly being underserved by developing therapies compared to the non-Hispanic/LatinX population. These findings provide valuable insights into the impact of gynecological cancers on specific demographic groups, emphasizing the urgency of targeted interventions to address disparities and improve outcomes.

Vepafestinib is a pharmacologically advanced RET-selective inhibitor with high CNS penetration and inhibitory activity against RET solvent front mutations

RET receptor tyrosine kinase is activated in various cancers (lung, thyroid, colon and pancreatic, among others) through oncogenic fusions or gain-of-function single-nucleotide variants. Small-molecule RET kinase inhibitors became standard-of-care therapy for advanced malignancies driven by RET. The therapeutic benefit of RET inhibitors is limited, however, by acquired mutations in the drug target as well as brain metastasis, presumably due to inadequate brain penetration. Here, we perform preclinical characterization of vepafestinib (TAS0953/HM06), a next-generation RET inhibitor with a unique binding mode. We demonstrate that vepafestinib has best-in-class selectivity against RET, while exerting activity against commonly reported on-target resistance mutations (variants in RETL730, RETV804 and RETG810), and shows superior pharmacokinetic properties in the brain when compared to currently approved RET drugs. We further show that these properties translate into improved tumor control in an intracranial model of RET-driven cancer. Our results underscore the clinical potential of vepafestinib in treating RET-driven cancers.

Radiomic predicts early response to CDK4/6 inhibitors in hormone receptor positive metastatic breast cancer

The combination of Cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) and endocrine therapy (ET) is the standard of care for hormone receptor-positive (HR + ), human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (MBC). Currently, there are no robust biomarkers that can predict response to CDK4/6i, and it is not clear which patients benefit from this therapy. Since MBC patients with liver metastases have a poorer prognosis, developing predictive biomarkers that could identify patients likely to respond to CDK4/6i is clinically important. Here we show the ability of imaging texture biomarkers before and a few cycles after CDK4/6i therapy, to predict early response and overall survival (OS) on 73 MBC patients with known liver metastases who received palbociclib plus ET from two sites. The delta radiomic model was associated with OS in validation set (HR: 2.4; 95% CI, 1.06-5.6; P = 0.035; C-index = 0.77). Compared to RECIST response, delta radiomic features predicted response with area under the curve (AUC) = 0.72, 95% confidence interval (CI) 0.67-0.88. Our study revealed that radiomics features can predict a lack of response earlier than standard anatomic/RECIST 1.1 assessment and warrants further study and clinical validation.

Poorly Differentiated Thyroid Carcinoma: Single Institution Series of Outcomes

BACKGROUND AND AIM

Poorly differentiated thyroid cancer (PDTC) is a rare but aggressive subtype of thyroid cancer that portends a poor prognosis. There remains a paucity of literature on PDTC outcomes. The aim of our study was to evaluate outcomes of PDTC in our tertiary care facility.

PATIENTS AND METHODS

We identified all histologically confirmed PDTC cases from 1997-2018 treated at our Institution and collected data points in an IRB-approved registry. We then conducted a retrospective study to assess outcomes and identified factors associated with inferior outcomes.

RESULTS

Twenty-three patients were identified with a median age at diagnosis of 60 years (range=39-89 years). Nineteen (83%) underwent total thyroidectomy. Eight (42%) patients had lymph node dissections and 2 (11%) underwent adjuvant radiation. Thirteen (68%) patients were treated with radioactive iodine (RAI). Those who underwent total thyroidectomy had a median overall survival (mOS) of 88 months, 5 year-OS of 56%, 5 year-local recurrence-free survival (LRFS) of 45%, and 5 year-distant recurrence-free survival (DRFS) of 36%. T4 disease had worse mOS (14 vs. 87 m, p=0.0082), and 5 year-LRFS rate (12 vs. 74%, p=0.0312) compared to T1-3. N0 disease had an improved mOS (172 vs. 32 m, p=0.0013), 5 year-LRFS rate (63 vs. 17%, p=0.0033), and 5 year-DRFS (57 vs. 0%, p=0.0252). Eight out of 23 patients (35%) were alive at last follow-up, with a median of 68 months (range=20-214). The most common cause of death was distant recurrence (73%). Six patients received systemic therapy with various tyrosine kinase inhibitors with a median duration on treatment of 7 months (range=1-30 months).

CONCLUSION

Advanced T and N stage were factors associated with significantly inferior outcomes. While select patients benefited with systemic treatment, it remains unclear if intensified locoregional therapy should be considered in patients with PDTC.

Abstract P5-13-27: Post-treatment vascularity and vessel shape are associated with survival and response to CDK4/6 inhibitors in hormone receptor-positive metastatic breast cancer (MBC)

Background: CDK 4/6 inhibitors (CDKI) with Endocrine therapy (ET) is mainstay treatment for hormone receptor-positive (HR+) Her2- metastatic breast cancer (MBC). Despite excellent efficacy, most patients develop resistance to CDKI limiting its utility. CDK4/6 are thought to act by upregulating VEGF causing tortuous angiogenesis and promoting cancer progression. Recent studies have shown aggressive tumors possess a higher density and tortuous vasculature. In this study, we evaluated if vascular radiomic features computationally extracted from liver CT scans pre- and post CDKI treatment could predict patient survival and treatment response. Method: From a registry of 350 patients on treatment with CDKI at institution 1(S1), 51 pts with HR+, Her2-, MBC patients with evidence of liver mets and disease progression (PFS) data were identified. 30 pts discontinued treatment due to progression or death, with a median time to progression of 195 days. Pre-treatment and first post-treatment CT exams were analyzed from 25 and 34 patients, respectively. Median time between scans was 128 days. To validate the prognostic value of our signature, a cohort of 29 patients with available OS data was identified from institution 2 (S2). A publicly available pre-trained deep learning model was applied to isolate liver metastases and vessels. Next, fast marching algorithm was applied to reduce vessels to their centerlines and divide the vasculature into constituent branches. 7 quantitative metrics were computed measuring vascularity of metastases and 3-D shape of hepatic vessels. First, the number (f1) and percentage (f2) of hepatic vessels arising from the tumor were computed. Vessel tortuosity - measuring the degree of twisting across a vessel - was computed separately for each branch. The mean (f3), standard deviation (f4), maximum (f5), skewness (f6), and kurtosis (f7) tortuosity values were calculated to summarize these measurements at patient level. The features were individually assessed at pre- and post-treatment for association with PFS at S1 in univariable Cox proportional hazards models. Features found to be associated in S1 were evaluated for association with OS in S2. Results: On the initial post-treatment scan, features of both tumor vascularization (f6 - HR=1.115 [1.039-1.196]; f7 - HR=10.646 [2.539-44.641]), as well as two features of vessel tortuosity (f3 - HR=0.011 [0.001-0.199]; f4 - HR=0.545 [0.313-0.949]) were significantly associated with PFS. Both tortuosity features were also significantly associated with OS in S2 (f3 - HR=0.085 [0.009-0.780]; f4 - HR=0.331 [0.130-0.842]). In addition the percentage (f7 - HR=6.445 [2.001-20.753]]),of vessels feeding the lesions was also significant in S2 while the number (f6 - HR=1.070 [0.966-1.184]), of vessels was not. No vessel metrics from the pre-treatment baseline exam were significantly associated with OS. Conclusions: Radiomic analysis of tumor vascularity and vessel tortuosity on CT scans post-CDK treatment was associated with patient survival and treatment response.

Table 1.Association of vessel features with PFS in Institution 1(S1)and OS in Institution 2(S2)S1- Pretreatment CT (n=25)S1 - Post-Treatment CT (n=34)S2 - Post-treatment CT - Validation (n=29)f1Tortuosity - Mean0.9912702470.852294696–f2Tortuosity - St. Dev0.7563942230.273115373–f3Tortuosity - Max0.1387051870.0022517550.02931473f4Tortuosity - Skewness0.254463710.0318270370.02022882f5Tortuosity - Kurtosis0.3058266760.108967601–f6Number of vessels feeding lesions0.419096650.0025747910.19306052f7Percentage of vessels feeding lesions0.0517942660.0012205950.00179103

Citation Format: Vidya Sankar Viswanathan, Nathaniel Braman, Priyanka Reddy, Siddharth Kunte, Jame Abraham, Alberto J Montero, Anant Madabhushi. Post-treatment vascularity and vessel shape are associated with survival and response to CDK4/6 inhibitors in hormone receptor-positive metastatic breast cancer (MBC) [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 P5-13-27.

Abstract P233: TAS0953/HM06 is effective in preclinical models of diverse tumor types driven by RET alterations

Fusions involving RET receptor tyrosine kinase are a common driver of tumors across different tissue types, such as lung, thyroid, colorectal, soft tissue and others. TAS0953/HM06 (hereby referred to as HM06) is a novel 2ndgeneration RET-specific inhibitor that is effective against RET solvent front (G810) and gatekeeper (V804) mutations. Here, we evaluated the efficacy of HM06 in lung and thyroid carcinomas, and soft-tissue sarcoma cell lines and PDXs derived from RET inhibitor-naive tumor samples or from tumors with acquired resistance to selpercatinib. HM06 was more effective than the RET multi-kinase inhibitors cabozantinib and vandetanib, and as effective as selpercatinib and pralsetinib in inhibiting growth of patient-derived and isogenic lung, thyroid and sarcoma cell lines (IC50=0.02-0.1 µM) harboring different RET fusions (KIF5B-RET, CCDC6-RET, TRIM33-RET, SPECCL1-RET) or activating mutations (RET C634W). Growth of non-tumor cells was up to 80-fold less sensitive to HM06 (IC50= 1.6 µM). Treatment of RET fusion-positive lung cancer cells with HM06 resulted in a dose-dependent inhibition of RET phosphorylation (Y905 and Y1062) and the downstream effectors AKT, ERK1/2, p70S6K and S6. Caspase 3/7 activity and markers of apoptosis (BIM, cleaved PARP) were induced by HM06 to a similar extent as pralsetinib and selpercatinib (dose range: 0.05-1 µM). HM06 induced changes in the core mediators of cell cycle regulation (upregulation of p27, downregulation of CCND1) and suppressed expression of MYC and ETV5. In vivo, HM06 blocked tumor growth and/or induced regression of up to 65% in seven patient-derived xenograft (PDX) models with RET fusions (five NSCLC PDXs, one sarcoma PDX and one NSCLC cell-line xenograft) to a similar extent as pralsetinib and selpercatinib. However, 6 weeks after cessation of treatment of the SPECCL1-RET-driven sarcoma PDX model, growth of tumors treated with HM06 was suppressed completely, whereas 3/5 pralsetinib-treated tumors and 1/5 selpercatinib-treated tumor regrew. Combination of HM06 and the MET inhibitor capmatinib effectively blocked growth of PDX tumors in a model that was derived from a patient sample that expressed RET fusion and METamplification, and was resistant to selpercatinib. These results suggest that HM06 may be an effective therapy for RET-driven tumors in a tissue-type agnostic manner and can effectively address common on-target and off-target resistance mechanisms such as RET G810X and V804X mutations. HM06 is currently in a phase 1 and 2 clinical trial for patients with advanced solid tumors with RET gene abnormalities (margaRET, NCT 04683250).

Citation Format: Igor Odintsov, Renate I. Kurth, Kota Ishizawa, Lukas Delasos, Allan J.W. Lui, Inna Khodos, Connor J. Hagen, Qing Chang, Marissa S. Mattar, Morana Vojnic, Siddharth Kunte, Annalisa Bonifacio, Claudio Giuliano, Elisa De Stanchina, Emily Cheng, Emanuela Lovati, Marc Ladanyi, Romel Somwar. TAS0953/HM06 is effective in preclinical models of diverse tumor types driven by RET alterations [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P233.

Novel patient-derived models of DSRCT enable validation of ERBB signaling as a potential therapeutic vulnerability

Desmoplastic small round cell tumor (DSRCT) is characterized by the t(11;22)(p13;q12) translocation, which fuses the transcriptional regulatory domain of EWSR1 with the DNA-binding domain of WT1, resulting in the oncogenic EWSR1-WT1 fusion protein. The paucity of DSRCT disease models has hampered preclinical therapeutic studies on this aggressive cancer. Here, we developed preclinical disease models and mined DSRCT expression profiles to identify genetic vulnerabilities that could be leveraged for new therapies. We describe four DSRCT cell lines and one patient-derived xenograft model. Transcriptomic, proteomic and biochemical profiling showed evidence of activation of the ERBB pathway. Ectopic expression of EWSR1-WT1 resulted in upregulation of ERRB family ligands. Treatment of DSRCT cell lines with ERBB ligands resulted in activation of EGFR, ERBB2, ERK1/2 and AKT, and stimulation of cell growth. Antagonizing EGFR function with shRNAs, small-molecule inhibitors (afatinib, neratinib) or an anti-EGFR antibody (cetuximab) inhibited proliferation of DSRCT cells. Finally, treatment of mice bearing DSRCT xenografts with a combination of cetuximab and afatinib significantly reduced tumor growth. These data provide a rationale for evaluating EGFR antagonists in patients with DSRCT.

This article has an associated First Person interview with the joint first authors of the paper.

Summary: Novel models of desmoplastic small round cell tumor (DSRCT) reveal a role for the ERBB pathway in regulating growth of this sarcoma and provide a rationale for evaluating EGFR antagonists in patients with DSRCT.

Early-Onset Pancreas Cancer: Clinical Descriptors, Genomics, and Outcomes

BACKGROUND

Recent evidence suggests a rising incidence of cancer in younger individuals. Herein, we report the epidemiologic, pathologic, and molecular characteristics of a patient cohort with early-onset pancreas cancer (EOPC).

METHODS

Institutional databases were queried for demographics, treatment history, genomic results, and outcomes. Overall survival from date of diagnosis was estimated using Kaplan-Meier method.

RESULTS

Between 2008 and 2018, 450 patients with EOPC were identified at Memorial Sloan Kettering. Median overall survival was 16.3  (95% confidence interval [CI] = 14.6 to 17.7) months in the entire cohort and 11.3  (95% CI = 10.2 to 12.2) months for patients with stage IV disease at diagnosis. Of the patients, 132 (29.3% of the cohort) underwent somatic testing; 21 of 132 (15.9%) had RAS wild-type cancers with identification of several actionable alterations, including ETV6-NTRK3, TPR-NTRK1, SCLA5-NRG1, and ATP1B1-NRG1 fusions, IDH1 R132C mutation, and mismatch repair deficiency. A total of 138 patients (30.7% of the cohort) underwent germline testing; 44 of 138 (31.9%) had a pathogenic germline variant (PGV), and 27.5% harbored alterations in cancer susceptibility genes. Of patients seen between 2015 and 2018, 30 of 193 (15.5%) had a PGV. Among 138 who underwent germline testing, those with a PGV had a reduced all-cause mortality compared with patients without a PGV controlling for stage and year of diagnosis (hazard ratio = 0.42, 95% CI = 0.26 to 0.69).

CONCLUSIONS

PGVs are present in a substantial minority of patients with EOPC. Actionable somatic alterations were identified frequently in EOPC, enriched in the RAS wild-type subgroup. These observations underpin the recent guidelines for universal germline testing and somatic profiling in pancreatic ductal adenocarcinoma.

Abstract PS5-42: Change in intra-lesion heterogeneity on CT predicts long-term survival following treatment with CDK4/6 inhibitors in hormone receptor-positive metastatic breast cancer (MBC)

Background: CDK 4/6 inhibitors are currently standard of care for patients CDK 4/6 inhibitors but currently lack validated predictive markers. We evaluated whether changes in intra-lesional heterogeneity, extracted computationally from routine computed tomography (CT) of MBC could predict survival following treatment with CDK 4/6 inhibitors.

Methods: 33 patients with ER+ breast cancer metastasized to the liver who received palbociclib in combination with anti-estrogen therapy were identified from a registry. For each patient, CT exams were acquired prior to treatment and following initiation of treatment (median time between scans of 106 +/- 48.6 days). Liver metastases were manually delineated on all scans with consultation of radiology reports. On each scan, gray level co-occurrence matrix (GLCM) entropy, a computational measure of intra-lesional heterogeneity, was calculated and averaged across all metastatic lesions and its change over treatment was computed. For comparison, response was also assessed via RECIST v1.1: 65% of patients had objective response/stable disease, while 35% had progressive disease on scan following initiation of treatment. Imaging metrics were assessed individually and in a multivariate comparison including clinical features for association with overall survival (OS) via a cox proportional hazards model.

Results: Change in intra-lesion heterogeneity was associated with OS with a hazard ratio [HR] of 2.82 (p=0.019). An increase in entropy between the pre- and treatment scan was associated with poorer viability on treatment including CDK inhibitors, indicating that a favorable response can be distinguished by a decrease in intra-lesion heterogeneity. RECIST response was also associated with OS (HR=0.24, p&lt;0.001). In a multivariable comparison with clinical variables, change in GLCM entropy and response per RECIST criteria both demonstrated multivariate significance. Neither the heterogeneity measure on the pre-treatment scan (HR=0.56, p=0.23) nor the scan acquired during treatment (HR=1.51, p=0.27) treatment scans alone were significantly associated with overall survival.

Conclusions: The change in lesion heterogeneity on clinical imaging following the initiation of treatment was found to offer independent value in distinguishing patients with favorable survival following CDK 4/6 inhibitor treatment.

Multivariate association of imaging features and clinical variables with overall survivalHazard ratio (HR)p-valueChange in Heterogeneity4.670.019RECIST response0.160.003PR status1.010.99HER2 status1.130.92Age1.040.26Pathology0.770.39Line of Treatment1.360.12

Citation Format: Nathaniel Braman, Siddharth Kunte, Kaustav Bera, Jame Abraham, Albert Montero, Anant Madabhushi. Change in intra-lesion heterogeneity on CT predicts long-term survival following treatment with CDK4/6 inhibitors in hormone receptor-positive metastatic breast cancer (MBC) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS5-42.

RET inhibition in novel patient-derived models of RET-fusion positive lung adenocarcinoma reveals a role for MYC upregulation

Multi-kinase RET inhibitors, such as cabozantinib and RXDX-105, are active in lung cancer patients with RET fusions; however, the overall response rates to these two drugs are unsatisfactory compared to other targeted therapy paradigms. Moreover, these inhibitors may have different efficacies against RET rearrangements depending on the upstream fusion partner. A comprehensive preclinical analysis of the efficacy of RET inhibitors is lacking due to a paucity of disease models harboring RET rearrangements. Here we generated two new patient-derived xenograft (PDX) models, one new patient-derived cell line, one PDX-derived cell line, and several isogenic cell lines with RET fusions. Using these models, we re-examined the efficacy and mechanism of action of cabozantinib and found that this RET inhibitor was effective at blocking growth of cell lines, activating caspase 3/7 and inhibiting activation of ERK and AKT. Cabozantinib treatment of mice bearing RET-fusion-positive cell line xenografts and two PDXs significantly reduced tumor proliferation without adverse toxicity. Moreover, cabozantinib was effective at reducing growth of a lung cancer PDX that was not responsive to RXDX-105. Transcriptomic analysis of lung tumors and cell lines with RET alterations showed activation of a MYC signature and this was suppressed by treatment of cell lines with cabozantinib. MYC protein levels were rapidly depleted following cabozantinib treatment. Taken together, our results demonstrate that cabozantinib is an effective agent in preclinical models harboring RET rearrangements with three different 5' fusion partners (CCDC6, KIF5B and TRIM33). Notably, we identify MYC as a protein that is upregulated by RET expression and down-regulated by cabozantinib treatment, opening up potentially new therapeutic avenues for combinatorial targeting RET-fusion driven lung cancers. The novel RET fusion-dependent preclinical models described herein represent valuable tools for further refinement of current therapies and the evaluation of novel therapeutic strategies.

Novel HER2-targeted therapies for HER2-positive metastatic breast cancer

Human epidermal growth factor receptor 2 (HER2) is overexpressed in approximately 20% of all breast cancers. Before the development of HER2-directed monoclonal antibodies, HER2-positive breast cancer was associated with a rather poor prognosis. With the advent of monoclonal HER2-targeting antibodies (trastuzumab and pertuzumab) and antibody-drug conjugates (trastuzumab emtansine [T-DM1] and trastuzumab deruxtecan), clinical outcomes for HER2-positive breast cancer have dramatically changed, and a greater proportion of patients in the nonmetastatic setting are cured. However, in the metastatic setting, resistance to anti-HER2 treatments still remains a major therapeutic challenge, underscoring the importance of developing novel HER2-directed therapies. Over the last year, there has been a dramatic shift in the current treatment paradigms for HER2-positive metastatic breast cancer, with recent U.S. Food and Drug Administration approvals of trastuzumab deruxtecan (DS-8201), neratinib, and tucatinib in combination with trastuzumab and capecitabine. The authors summarize recent phase 3 data with novel HER2-targeted therapies as well as phase 1 and 2 data with other novel HER2-targeting agents.

Radiomics risk score (RRS) on CT to predict survival and response to CDK 4/6 inhibitors in hormone receptor (HR) positive metastatic breast cancer (MBC)

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Background: The addition of CDK 4/6 inhibitors (CDK) to endocrine therapy (ET) is the standard of care for HR+ MBC. Currently, no robust predictive markers for CDK inhibitors exist. We hypothesized that baseline imaging features on pre-treatment CT scans using machine learning could correctly identify responders to CDK. Methods: From a retrospective pt registry, 46 pts with HR+ MBC who received palbociclib (palbo) plus ET and had liver metastases were identified, and divided at random into equally sized training and testing cohorts. Patients with objective response/stable disease per RECIST v1.1 were defined as ‘responders’ (65%), and those with progressive disease within 6 months were ‘non-responders’ (35%). The median age at diagnosis was 62. All pts were ER+ and 4% were HER2+. 65% pts received palbo as 1st or 2nd line tx. 503 radiomic texture features measuring subtle differences in lesion heterogeneity on a pixel level were extracted on pre-treatment CT within the first lesion measured for RECIST assessment. An elastic net Cox proportional hazards model was constructed within the training set to derive a Radiomics Risk Score (RRS), which was evaluated for association with prognosis and response within the testing set. A risk score threshold was chosen in the training set for stratifying patients into high and low risk groups. Results: The RRS consisted of 4 radiomic features indicating intratumoral heterogeneity to be associated with poor outcome. In the independent testing set (n = 23), RRS was continuously associated with survival (p = .0027) on multivariate analysis, along with age and RECIST response (Table). Categorical risk groups were similarly associated with survival in the testing set (p = .00491, HR = 4.03, CI = 0.6772). Median survival time in low and high risk groups were 2.33 and 0.673 years, respectively. When compared against RECIST response in the testing set, RRS was found to also be predictive of response with an ROC curve of 0.675. Conclusions: Radiomics analysis was able to predict response and survival in HR+ MBC pts prior to initiation of treatment with CDK. [Table: see text]

Early-onset pancreatic ductal adenocarcinoma (PDAC) at Memorial Sloan Kettering Cancer Center (MSKCC)

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Background: PDAC is a leading and rising cause of cancer-related mortality. There is infrequent description of patients and outcomes with PDAC diagnosed aged <=50 years old (Early onset PC: EOPC). We reviewed the epidemiology, risk factors, oncologic outcomes and genomic data of EOPC pts at MSKCC. Methods: Using an institutional dataline search, N=364 patients were identified with EOPC between 2008-2014 at MSKCC. N= 282 were included in final analysis based on data completeness. Results: Baseline characteristics are summarized in table 1. The average patient was male, aged between 40- 50 years, BMI 24 and had metastatic disease at diagnosis. Family history of malignancy was present in N= 216 patients. The median overall survival (OS) for stages IIA, IIB, III and IV was 19.2, 21.8, 18.8 and 9.7 months respectively. Age, gender, diabetes and smoking history did not have a significant impact on OS. No difference in OS was noted between the groups who received gemcitabine based first-line chemotherapy compared to those with 5-fluorouracil based regimen in metastatic disease (9.9 vs 12 months, p= 0.315). Conclusions: EOPC represents a small subset of patients with PDAC and very rarely arises < 30 years of age. For this MSKCC cohort, outcomes appear similar to patients with average age onset PDAC. Further analyses on genomic characteristics may provide insight into outcomes and genetic underpinnings of EOPC. [Table: see text]

Role of ERBB signaling in RET-rearranged lung cancer and contribution of EGFR amplification to cabozantinib resistance

11583

Background: Lung cancers driven by oncogenic RET fusions have lower response rates to targeted monotherapy such as cabozantinib (28%) relative to response rates typically observed in ALK- or ROS1- rearranged lung adenocarcinomas (60-80%). Methods: To identify targetable co-dependencies or cooperating pathways for RET fusion-positive lung cancers, we performed high-throughput chemical and genetic screens to find FDA-approved drugs or genes that when inhibited, would synergize with cabozantinib in RET fusion-positive lung cancer cell lines. In addition we performed NGS of a pair of pre-treatment and post-cabozantinib progression samples. Results: We identified EGFR siRNAs and anti-EGFR drugs as synergistic with cabozantinib. Combinations of drugs that target EGFR (cetuximab, afatinib, erlotinib, gefitinib, neratinib) and RET (cabozantinib, CEP-32496, lenvatinib, vandetanib) were more effective at reducing growth of RET cell lines than any single agent in vitro and in xenograft models. Cabozantinib treatment of RET fusion-positive cell lines inhibited EGFR and RET phosphorylation, an observation not seen in RET wild-type cell lines. Co-immunoprecipitation studies reveal that RET and EGFR interact. Ectopic expression of CCDC6-RET in NIH-3T3 or human bronchial epithelial cells resulted in upregulation of multiple ERBB receptors and ligands (not seen in a ROS1 fusion-positive cell line) and a concomitant increase in EGFR stability. Treatment with ERBB pathway ligands or overexpression of EGFR decreased sensitivity to cabozantinib in two RET fusion-positive cell lines. Finally, sequencing of a pair of pre-treatment and post-progression samples from a lung cancer patient treated with cabozantinib revealed acquired amplification of EGFR in the latter sample. Conclusions: Taken together, these results suggest that the tumorigenic potential of RET fusion oncogenes is dependent on deregulation of ERBB-activated pathways and that a combination of RET and EGFR drugs could be more effective in treating RET fusion-positive tumors. Moreover, amplification of EGFR is a potential driver of resistance to cabozantinib in RET-rearranged lung cancers.

Assessing fracture risk in early stage breast cancer patients treated with aromatase-inhibitors: An enhanced screening approach incorporating trabecular bone score

Introduction

Aromatase-inhibitors (AIs) are commonly used for treatment of patients with hormone-receptor positive breast carcinoma, and are known to induce bone density loss and increase the risk of fractures. The current standard-of-care screening tool for fracture risk is bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA). The fracture risk assessment tool (FRAX®) may be used in conjunction with BMD to identify additional osteopenic patients at risk of fracture who may benefit from a bone-modifying agent (BMA). The trabecular bone score (TBS), a novel method of measuring bone microarchitecture by DXA, has been shown to be an independent indicator of increased fracture risk. We report how the addition of TBS and FRAX®, respectively, to BMD contribute to identification of elevated fracture risk (EFR) in postmenopausal breast cancer patients treated with AIs.

Methods

100 patients with early stage hormone-positive breast cancer treated with AIs, no prior BMAs, and with serial DXAs were identified. BMD and TBS were measured from DXA images before and following initiation of AIs, and FRAX® scores were calculated from review of clinical records. EFR was defined as either: BMD ≤−2.5 or BMD between −2.5 and −1 plus either increased risk by FRAX® or degraded microstructure by TBS.

Results

At baseline, BMD alone identified 4% of patients with EFR. The addition of FRAX® increased detection to 13%, whereas the combination of BMD, FRAX® and TBS identified 20% of patients with EFR. Following AIs, changes in TBS were independent of changes in BMD. On follow-up DXA, BMD alone detected an additional 1 patient at EFR (1%), whereas BMD+ FRAX® identified 3 additional patients (3%), and BMD+FRAX®+TBS identified 7 additional patients (7%).

Conclusions

The combination of FRAX®, TBS, and BMD maximized the identification of patients with EFR. TBS is a novel assessment that enhances the detection of patients who may benefit from BMAs.

Fast dissolving strips: A novel approach for the delivery of verapamil

OBJECTIVE

Fast dissolving drug delivery system offers a solution for those patients having difficulty in swallowing tablets/capsules etc. Verapamil is a calcium channel blocker used as an antianginal, antiarrhythmic, and antihypertensive agent with extensive first pass metabolism which results in less bioavailability. This work investigated the possibility of developing verapamil fast dissolving strips allowing fast, reproducible drug dissolution in the oral cavity; thus bypassing first pass metabolism.

MATERIALS AND METHODS

The fast dissolving strips were prepared by solvent casting technique with the help of HPMC E6 and maltodextrin. The strips were evaluated for drug content uniformity, film thickness, folding endurance, in vitro disintegration time, in vitro dissolution studies, surface pH study, and palatability study.

RESULTS

Official criteria for evaluation parameters were fulfilled by all formulations. Disintegration time showed by formulations was found to be in range of 20.4-28.6 sec. Based on the evaluation parameters, the formulation containing 2% HPMC E6 and 3.5% maltodextrin showed optimum performance against other formulations.

CONCLUSION

It was concluded that the fast dissolving strips of verapamil can be made by solvent casting technique with enhanced dissolution rate, taste masking, and hence better patient compliance and effective therapy.