Citations

Abstract Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype with low overall survival rates and high molecular heterogeneity; therefore, few targeted therapies are available. The luminal androgen receptor (LAR) is the most consistently identified TNBC subtype, but the clinical utility has yet to be established. Here, we constructed a novel genomic classifier, LAR-Sig, that distinguishes the LAR subtype from other TNBC subtypes and provide evidence that it is a clinically distinct disease. A meta-analysis of seven TNBC datasets (n = 1086 samples) from neoadjuvant clinical trials demonstrated that LAR patients have significantly reduced response (pCR) rates than non-LAR TNBC patients (odds ratio = 2.11, 95% CI: 1.33, 2.89). Moreover, deconvolution of the tumor microenvironment confirmed an enrichment of luminal epithelium corresponding with a decrease in basal and myoepithelium in LAR TNBC tumors. Increased immunosuppression in LAR patients may lead to a decreased presence of cycling T-cells and plasma cells. While, an increased presence of myofibroblast-like cancer-associated cells may impede drug delivery and treatment. In summary, the lower levels of tumor infiltrating lymphocytes (TILs), reduced immune activity in the micro-environment, and lower pCR rates after NAC, suggest that new therapeutic strategies for the LAR TNBC subtype need to be developed.

Clinical trials reporting the robust antitumor activity of immune checkpoint inhibitors (ICIs) in microsatellite instability-high (MSI-H) solid tumors have used tissue-based testing to determine the MSI-H status. This study assessed if MSI-H detected by a plasma-based circulating tumor DNA liquid biopsy test predicts robust response to ICI in patients with pancreatic ductal adenocarcinoma (PDAC). Retrospective analysis of patients with PDAC and MSI-H identified on Guardant360 from October 2018 to April 2021 was performed; clinical outcomes were submitted by treating providers. From 52 patients with PDAC +MSI-H, outcomes were available for 10 (19%) with a median age of 68 years (range: 56–82 years); the majority were male (80%) and had metastatic disease (80%). Nine of 10 patients were treated with ICI. Eight out of nine patients received single-agent pembrolizumab (8/9), while one received ipilimumab plus nivolumab. The overall response rate by Response Evaluation Criteria in Solid Tumors was 77% (7/9). The median progression-free survival and overall survival were not reached in this cohort. The median duration of treatment with ICI was 8 months (range: 1–24), and six out of seven responders continued to show response at the time of data cut-off after a median follow-up of 21 months (range: 11–33). Tissue-based MSI results were concordant with plasma-based G360 results in five of six patients (83%) who had tissue-based test results available, with G360 identifying one more patient with MSI-H than tissue testing. These results suggest that detecting MSI-H by a well-validated liquid biopsy test could predict a robust response to ICI in patients with PDAC. The use of liquid biopsy may expand the identification of PDAC patients with MSI-H tumors and enable treatment with ICI resulting in improved outcomes.

Abstract Background: Sarcopenia is one of the early pathological features of cancer cachexia, yet the effect of sarcopenia on clinical outcomes in patients with advanced HCC is unclear. Our objective was to determine the effect of Sarcopenia on response to systemic therapy with advanced HCC. Methods: Patients with unresectable and advanced liver cancer were retrospectively evaluated between 2010 to 2019. Skeletal muscle area (SMA) was computed with a previously validated computed tomography (CT) body composition AI algorithm. The skeletal muscle index (SMI) was derived from the skeletal muscle area (SMA) (cm2) divided by patient height (m2) calculated from images at the level of L3 on pretreatment CT. Sarcopenia cutoffs for females was less than 39 cm2/m2 SMI or less than 50 cm2/m2 SMI for males. Patients’ demographics, systemic treatment response, toxicity, progression-free survival (PFS) and overall survival (OS) were compared between first-line therapy groups. Kaplan-Meier and Cox proportional hazards regression were used for survival analysis comparisons. Results: A total of 146 patients with advanced HCC were assessed from Mayo Clinic Arizona and Emory University. Seventy-six patients received immunotherapy as first-line treatment and seventy patients received TKI as first-line therapy. Sarcopenia at baseline was assessed in a total of 91 patients at first-line systemic treatment: n=48 with immunotherapy (IO) and n=43 with tyrosine kinase inhibitor (TKI). Sarcopenia was more prevalent in male patients (p=0.009), and in patients with low BMI (p=0.02). When comparing those with sarcopenia at baseline, higher response rate was observed in patients treated with IO without sarcopenia (47% versus 15%, p=0.019), this was not observed in TKI group. Interestingly, median PFS and OS was not significantly changed in patients with or without sarcopenia treated with IO or TKI on first-line therapy. Conclusions: Sarcopenia was associated with reduced response rate (RR) in patients treated with IO, but not in TKI groups. Both didn’t translate into deleterious effect in PFS and or OS. Further research with sufficient adjustments for confounding factors is warranted to better elucidate the prognostic value of sarcopenia in these patients. Citation Format: Gehan Botrus, Pedro Luiz Serrano Uson Junior, Heidi Kosiorek, Mehmet Akce, Isabela Chang, Zhubene Mesbah, Eric Yancey, Daniel Blezek, Jason Klug, Lana Khalil, Puneet Raman, Mohamad Sonbol, Mitesh Borad, Daniel Ahn, Tanios Bekaii-Saab. Prognostic impact of Sarcopenia on clinical outcomes in advanced hepatocellular carcinoma (HCC) treated with systemic therapy [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 6274.

Abstract Introduction: CFT7455 is a highly potent and novel Ikaros Family Zinc Finger Protein 1/3 (IKZF1/3) degrader. In xenograft models, CFT7455 has more potent IKZF1/3 degradation compared to other degraders. Early observations from the FIH clinical trial (NCT04756726) along with supporting translational studies are presented here. Methods: Pre-clinical studies comparing CFT7455 and CC-92480 in both in vitro and xenograft models were performed. The pre-clinical studies’ results coincided with observations from the on-going clinical trial. The clinical trial is an open-label, Phase 1/2, multi-center, FIH study in heavily pretreated relapsed/refractory (R/R) MM and non-Hodgkin’s lymphoma (NHL) patients evaluating safety, tolerability, and PK of CFT7455. Eligible MM patients are R/R to therapy and are not candidates for regimens known to provide clinical benefit. A starting dose of 50 μg QD 21 days on/7 days off (21/7) in 28-day cycles was administered. Results: CFT7455 and CC-92480 showed similar cereblon binding profiles and in vitro IKZF1/3 degradation kinetics, translating into sub-nanomolar GI50 values in proliferation assays across a panel of MM cell lines. In the NCI-H929 xenograft model, 100 μg/kg/day of CFT7455 resulted in durable tumor regressions, while 1000 μg/kg/day of CC-92480 gave tumor stasis. Similar results were seen in a systemic model of MM, MM1.S. Both compounds achieved >95% IKZF3 degradation in tumors 4h post dose. At 48h post dose, CFT7455 was more effective than CC-92480 in maintaining IKZF3 degradation (65% vs. 6% respectively). When levels of CFT7455 and CC-92480 in plasma and tumor were compared, CFT7455 concentrations were > DC80 in tumor 48h post dose, while CC-92480 levels were undetectable in tumor and plasma, demonstrating CFT7455 has longer exposure resulting in sustained IKZF1/3 degradation in pre-clinical models. In cohort A, 5 heavily pre-treated MM patients (pts) received single agent CFT7455. 4 pts have received at least 3 cycles, with 2 pts receiving 5 cycles. Neutropenia (grade 4) was observed in 3/5 pts without coincident fever or infection. Additionally, a 2-4 fold accumulation in plasma CFT7455 exposure at steady state was observed. Early pharmacodynamic (PD) data demonstrates deep persistent degradation of IKZF3 (~100%) and serum free light chain reduction (up to 72%) in response to treatment. Stable disease has been observed in 34 pts, suggesting clinical benefit. Conclusions: While CFT7455 showed clinical benefit at 50 ug with deep target degradation, neutropenia was dose limiting. PK/PD modeling suggests alternative dosing regimens may result in increased tolerability with preserved efficacy, and evaluation of them is underway. Updated results will be presented at the meeting. Citation Format: Sagar Lonial, Shambavi Richard, Jeffrey V Matous, Andrew J. Yee, Urvi Shah, Neha Mehta-Shah, Thomas Martin, Eli Muchtar, Sikander Ailawadhi, Paul G. Richardson, Manisha Bhutani, Samantha Perino, Jason Kirby, Roman V. Agafonov, Prasoon Chaturvedi, Bradley Class, Matthew Schnaderbeck, Michael R. Palmer, Cathleen Gorman, Oliver Schoenborn-Kellenberger, Amanda Hoerres, Stewart L. Fisher, Roy M. Pollock, Adam Crystal, Michelle Mahler, Jesus Bardeja. Pharmacokinetic (PK) profile of a novel IKZF1/3 degrader, CFT7455, enables significant potency advantage over other IKZF1/3 degraders in models of multiple myeloma (MM) and the results of the initial treatment cohort from a first-in-human (FIH) phase 1/2 study of CFT7455 in MM [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 CT186.

Abstract Cachexia is a multifactorial syndrome characterized by extensive body weight, lean muscle and fat mass loss. Cachexia worsens cancer patient prognoses and contributes to poor chemotherapy tolerance and response rates. About 80% of pancreatic cancer patients suffer from cachexia and one-third die due to cachexia-related complications such as respiratory failure and cardiac arrest. Although there has been considerable research into cachexia mechanisms and interventions, there are, to date, no FDA-approved cachexia therapies. A major contributing factor could be the failure of animal models to accurately recapitulate the human condition. In this study, we generated an aged murine model of pancreatic cancer cachexia to compare cachexia progression in young versus aged tumor-bearing mice. Comparative transcriptomic analyses of the muscles identified 3-methyladenine (3-MA), a known autophagy inhibitor, as a candidate anti-wasting compound. In vitro analyses confirmed anti-wasting effects while in vivo analysis demonstrated that 3-MA could rescue muscle wasting and suppress tumor growth. Surprisingly, transcriptome analyses of 3MA-treated tumor cells did not reveal autophagy-related signatures but instead implicated Perp as a novel 3-MA target. Probing further, we 1) observed significantly higher expression of Perp in pancreatic cancer cell lines compared to control cells, 2) noted a survival disadvantage associated with elevated PERP in the TCGA database, 3) found that PERP knockdown in cancer cells led to reduced tumor proliferation, and 4) confirmed that 3-MA-associated Perp reduction inhibited tumor growth. Moreover, we also demonstrate that survival benefits associated with 3MA is independent of tumor progression. Finally, we queried Perp expression in human tumor samples and observed increased Perp expression in adenocarcinoma regions compared to tumor adjacent tissue. Taken together, we report a novel mechanism linking 3-MA to Perp inhibition, and further implicate Perp as a novel tumor promoting factor in pancreatic cancer. Citation Format: Aneesha Dasgupta, Paige C. Arneson-Wissink, Rebecca E. Schmitt, Dong Seong Cho, Alexandra M. Ducharme, Tara L. Hogenson, Eugene W. Krueger, William R. Bamlet, Lizhi Zhang, Gina Razidlo, Martin E. Fernandez-Zapico, Jason D. Doles. Identification of perp as a tumor promoter in pancreatic cancer via the utilization of an aged model of cancer cachexia [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 3995.

Abstract Men of African ancestry (MAA) have the highest global incidence and mortality of prostate cancer (PCa); however, the biology underlying this harsh disease presentation remains poorly understand, largely due to Africans and people within the African diaspora being under-represented in genomics research. MAA are younger at diagnosis, have higher tumor volume at diagnosis and have higher tumor aggression compared to European American men. Additionally, genomic profiling continues to show that PCa etiology and phenotype are influenced by higher amounts of African ancestry and that West African ancestry is associated with unique genomic alterations. Herein we utilize whole exome sequencing of a unique cohort of 45 advanced stage, treatment naïve Nigerian primary PCa tumors and 11 unmatched non-tumor tissue to compare genomic variants with African (AA) and European (EA) American TCGA PCa tumors. Nigerian samples were collected from 6 sites in central and southwest Nigeria. After whole exome sequencing, samples were processed using GATK best practices. Four genes [BRCA1 (100%), BARD1 (45%), BRCA2 (27%) and PMS2 (18%)] had germline variants in at least two Nigerian non-tumor samples. Across 111 germline variants, the AA cohort reflected a pattern [BRCA1 (68%), BARD1 (34%), BRCA2 (28%) and PMS2 (16%)] similar to Nigerian samples. Of the most frequently mutated genes, BRCA1 showed a statistically (p ≤ 0.05) higher mutation frequency in MAA. Disaggregating gene level mutation frequencies by variant revealed both ancestry linked and Nigerian specific germline variant patterns. Driven by rs799917, BRCA1 showed increasing mutation frequency as African admixture increased. BRCA2_rs11571831 was only present in MAA and BRCA2_rs766173 was increased in Nigerian men. 133 somatic variants were present in 26 PCa associated genes within the Nigerian tumor cohort. Nine genes [BRCA2 (27%), APC (20%), ATM (20%), BRCA1 (13%), DNAJC6 (13%), EGFR (13%), MAD1L1 (13%), MLH1 (11%) and PMS2 (11%)] showed mutation frequencies above 10%. Compared to TCGA cohorts, BRCA2, APC and BRCA1 showed statistically significant increases in Nigerian tumors. The Nigerian cohort variant pattern shared similarities (cosign similarities ≥ 0.734) with COSMIC signatures 5 and 6 and mutated genes showed significant (q < 0.001) GO and functional enrichment in mismatch repair and non-homologous repair deficiency (HRD) pathways. Here, we show that variants in DDR genes are increased in Nigerian PCa and that a portion of those variants correlate with increased African ancestry. Moreover, we identify variants of unknown significance that may contribute to population specific routes of tumorigenesis and treatment. These results present the most comprehensive characterization of the Nigerian PCa exome to date and further highlight the need to increase study population diversity. Citation Format: Jason A. White, Ernest Kaninjing, Kayode A. Adeniji, Paul Jibrin, John O. Obafunwa, Chidiebere N. Ogo, Mohammed Faruk, Solomon Rotimi, Ademola Popoola, Omolara A. Fatiregun, Olabode P. Oluwole, Balasubramanyam Karanam, Wei Tang, Stefan Ambs, Folake T. Odedina, Damali N. Martin, Clayton Yates. Tumor only analysis of whole exome sequencing from a multi-institutional Nigerian prostate cancer cohort reveals DNA repair genes associated with African ancestry [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 1507.

INTRODUCTION: Prenatal visits via a virtual platform are increasingly offered to patients. Previous studies have shown favorable acceptance by patients. The COVID-19 pandemic dramatically accelerated adoption of this new technology. This study was designed to compare documentation of maternal blood pressure and weight between virtual visits and traditional face-to-face visits. METHODS: The study is a retrospective comparison of documentation of blood pressure and maternal weight between virtual and traditional face-to-face prenatal visits between January 2019 and June 2021. IRB exemption was obtained. The electronic medical record of a large midwest U.S. health system was utilized to identify prenatal visit encounters for all patients at all gestations. The visits were grouped into virtual visits and face-to-face visits. Data analytics were used to compare documentation of maternal weight, systolic blood pressure, and diastolic blood pressure for both subgroups. Data were further broken down by month to show comparison over time. Comparison was also made by gestational age. RESULTS: A total of 108,428 prenatal visits were identified. Of these, 7,004 (6.5%) were virtual visits. Appropriate documentation of blood pressure was absent in 3% of face-to-face visits and 46% of virtual visits. For the maternal weight, data were missing for 3% of face-to-face visits and 66% of virtual visits. CONCLUSION: Studies validating the safety of virtual prenatal visits are lacking. This analysis identifies obstacles that need to be overcome to improve the safety of virtual care.

Abstract Introduction: Radiotherapy has long been examined in association with second malignancies, but the impact of radiotherapy for initial primary lung cancer (IPLC) on the risk of second primary lung cancer (SPLC) remains controversial. We evaluated associations between IPLC radiotherapy and the risks of SPLC and overall mortality among lung cancer survivors. Methods: We identified 689,785 patients diagnosed with IPLC in 1988-2013 from SEER. We applied cause-specific Cox (CSC) regression to evaluate association between IPLC radiotherapy and SPLC risk, adjusting for age at IPLC diagnosis, IPLC stage and histology, and prior history of cancer. To allow a latency period of exposure to IPLC radiotherapy on SPLC risk, we performed subgroup analyses restricted to patients who survived ≥5 and ≥10 years after IPLC diagnosis. Using Cox regression, we evaluated association between IPLC radiotherapy and overall mortality, adjusting for the same covariates used in the CSC analysis. Mediation analysis quantified the indirect effect of IPLC radiotherapy on overall mortality mediated through radiotherapy-driven SPLC diagnosis. Validation utilized data from 7,758 IPLC patients (496 SPLCs) at Mayo Clinic. Results: Of 689,785 IPLC patients, 18,818 (2.7%) developed SPLC in SEER. IPLC patients treated with radiotherapy had a reduced SPLC risk versus non-irradiated patients when evaluated at the time of initial diagnosis (cause-specific hazard ratio [csHR]=0.90, P<1x10-6). However, the association between IPLC radiotherapy and SPLC risk was reversed when analyses were restricted to those who survived at least 5 years (csHR=1.08, P=0.01) and 10 years (csHR=1.16, P=0.009), thus long-term survivors treated with IPLC radiotherapy having a significantly increased risk of SPLC. Mayo Clinic data showed consistent results, with the effect of IPLC radiotherapy increasing from csHR of 2.41 (P<1x10-6) to 3.38 (P=0.001) among 5-year and 10-year survivors, respectively. Similarly, compared to non-irradiated patients, those treated with IPLC radiotherapy showed a significantly increased risk of overall mortality among 10-year survivors (hazard ratio [HR]=1.46, P<1x10-6 in SEER and HR=1.54, P=5.1X10-5 in Mayo Clinic). Mediation analysis showed that a substantial proportion of the total effect of IPLC radiotherapy on overall mortality—ranging from 32% to 59%—was due to radiotherapy-driven SPLC among 10-year survivors in SEER and Mayo Clinic. Conclusions: IPLC radiotherapy is associated with increased risks of SPLC and overall mortality, with its effects more pronounced among long-term survivors. Citation Format: Eunji Choi, Vicky T. Lam, Jacqueline A. Aredo, Ashok V. Kumar, Jason Wampfler, Julie T. Wu, David C. Christiani, Iona Cheng, Christopher I. Amos, Rayjean J. Hung, Leah M. Backhus, Joel W. Neal, Heather A. Wakelee, Ping Yang, Summer S. Han. Long term effect of radiotherapy on risk of second primary lung cancer and overall mortality among lung cancer patients [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 3445.

Abstract Cancer cachexia, and its associated complications, represent a large and currently untreatable roadblock to better cancer therapy. Many potential therapies have been suggested and tested - including appetite stimulants, targeted cytokine blockers, and nutritional supplementation, but effective therapies have still not found a place in the clinic. Thus, a new approach to treating cancer cachexia is warranted. Members of the Kruppel-like factor family play wide-ranging and important roles in the development, maintenance, and metabolism of muscle. Upon review both our own and multiple publically available datasets, we identified KLF10 upregulation in a multitude of cachectic muscles - including in pancreatic, lung, and colon cancer mouse models and in human cachexia patients. Thus, in this study, we interrogated loss-of-function of KLF10 in the context of pancreatic cancer associated muscle wasting. Ex vivo experiments on satellite cells isolated from KLF10 Knockout (KO) mice showed resistance to the effect of KPC conditioned media on atrophy. In vivo studies using a KLF10 KO mouse model showed that upon orthotopic implantation of T4-KPC cells, the mice demonstrated a significant preservation of lean mass and significant alterations in the expression of muscle-specific ubiquitin ligases Trim63 and Fbxo32, as well as other genes implicated in atrophy, calcium signaling, and autophagy. Pathway analysis of RNA-seq data from these mice identified TGF-B, a known inducer of KLF10, as an important upstream regulator of the response. Further in vivo experimentation showed KLF10 KO mice to be resistant to the atrophic effects of TGF-B injections. In conclusion, we report a novel role of KLF10 in the manifestation of cachexia in pancreatic cancer. Citation Format: Daniel F. Gibbard, Aneesha Dasgupta, Rebecca E. Schmitt, Alexandra M. Ducharme, Paige C. Arneson, Elizabeth S. Bruinsma, John R. Hawse, Jason D. Doles. TGF-B/KLF10 signaling regulates muscle wasting in pancreatic cancer cachexia [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 3985.