Williams, Terence M.

Objectives Black/African American (B/AA) pancreatic ductal adenocarcinoma (PDAC) patients have worse clinical outcomes than White patients and are underrepresented in genomic databases. We aimed to expand our understanding of the PDAC somatic landscape from a diverse cohort. Materials and Methods Formalin-fixed paraffin-embedded specimens from 24 surgically resected PDAC cases were collected, with self-reported race/ethnicity. Whole exome sequencing was performed on malignant and benign tissue. Bioinformatics analysis included deduction of genetic ancestry and somatic mutational analysis, with comparisons to public datasets. Results Out of 24 cases, 17 identified as B/AA race; genetic ancestry analysis confirmed proportions of Sub-Saharan African ancestry greater than 47%. The most commonly mutated genes included KRAS , TP53 , SMAD4 , and CDKN2A . Comparison of mutations in our cohort versus publicly available, predominantly White datasets showed higher mutation frequencies of ATM, RREB1, BRCA1/2, KDM6A, ARID1A, BRAF, and MYC ( P < 0.04). When cohorts were combined and analyzed by race, no mutation frequencies differences were observed, including KRAS . Conclusions Genomic analysis of PDAC tumors from B/AA and White patients demonstrate similarities in mutation frequencies. Larger studies are needed to further understand molecular characterizations across continental subpopulations. This study provides further rationale for equitable representation of diverse patients in genomic databases and clinical trials.

Importance Neoadjuvant therapy (NT) is an increasingly used treatment strategy for patients with localized pancreatic ductal adenocarcinoma (PDAC). Little research has been conducted on cancer care delivery during NT, and the standards for optimal delivery of NT have not been defined. Objective To develop consensus best practices for delivering NT to patients with localized PDAC. Design, Setting, and Participants This study used a modified Delphi approach consisting of 2 rounds of voting, and a series of virtual conferences (from October to December 2023) to reach expert consensus on candidate best practice statements generated from a systematic review of the literature and expert opinion. An interdisciplinary panel was formed including 47 North American experts from surgical, medical, and radiation oncology, radiology, pathology, gastroenterology, integrative oncology, anesthesia, pharmacy, nursing, cancer care delivery research, and nutrition as well as patient and caregiver stakeholders. Main Outcome and Measures Statements that reached 75% agreement or greater were included in final consensus statements. Results Of the 47 participating panel members, 27 (57.64%) were male, and the mean (SD) age was 47.6 (8.2) years. Physicians reported completing training a mean (SD) 14.6 (8.6) years prior and seeing a mean (SD) 110.6 (38.4) patients with PDAC annually; 35 (77.7%) were in academic practice. Final consensus was reached on 82 best practices for delivering NT. Of these, 38 statements focused on pre-NT practices, including diagnosis and staging (n = 15), evaluation and optimization (n = 20), and decision-making (n = 3); 29 statements defined best practices during NT, including initiation (n = 3), delivery of therapy (n = 8), restaging practices (n = 12), and management of complications during NT (n = 6); and 15 best practices were identified to guide treatment post-NT, focusing on surgery (n = 7), pathology (n = 4), and follow-up (n = 3). Conclusions Using a modified Delphi consensus technique, best practice guidelines were developed focusing on the optimal standards for delivering NT to patients with localized PDAC. Given the prognostic importance of completing multimodality therapy, efforts to standardize and optimize the delivery of NT represent an immediate opportunity to decrease care variation and improve outcomes for patients with PDAC. Future research should focus on validating and implementing best practice standards into clinical practice.

Importance Outcomes for patients with unresectable stage III non–small cell lung cancer (NSCLC) treated with chemoradiation therapy (CRT) have improved with adjuvant immune checkpoint inhibitors, with a reported 5-year overall survival benefit of approximately 10% for adjuvant durvalumab vs placebo after completion of CRT without progression and with preserved performance status. Starting atezolizumab prior to CRT may allow more patients to benefit from immunotherapy. Objective To evaluate clinical outcomes of patients treated with atezolizumab before and after CRT for unresectable stage III NSCLC. Design, Setting, and Participants This single-cohort, phase II, nonrandomized controlled trial was conducted at 11 US sites. Patients with pathologically confirmed, unresectable stage III NSCLC who were treatment naive and had good performance status were enrolled between January 3, 2018, and July 24, 2019. Data were locked on March 21, 2023. Interventions Patients received four 21-day cycles of atezolizumab, 1200 mg intravenously, with therapy administered on day 1 of each cycle. Patients not experiencing tumor progression continued to CRT (60 Gy to involved fields) concurrent with weekly carboplatin area under the curve of 2 and paclitaxel, 50 mg/m 2 , followed by planned consolidation carboplatin area under the curve of 6 and paclitaxel, 200 mg/m 2 , for two 21-day cycles. Patients not experiencing progression continued atezolizumab, 1200 mg, every 21 days to complete 1 year of therapy. Main Outcomes and Measures The primary end point was the disease control rate at 12 weeks. Secondary end points were progression-free survival, overall survival, overall response rate, safety, and translational science end points. Results A total of 62 patients (median [range] age, 63.9 [38.1-86.5] years; 32 female [51.6%]) were enrolled and received at least 1 dose of atezolizumab. The disease control rate at 12 weeks was 74.2% (80% CI, 65.7%-81.4%). Median progression-free survival was 30.0 months (95% CI, 15.8 to not evaluable), and the median overall survival was not reached. The overall survival rate at 24 months was 73.7% (95% CI, 63.4%-85.7%), and the overall response rate was 66.2%. Seventeen patients (27.4%) experienced grade 3 or higher immune-related adverse events, including 1 with grade 5 pneumonitis and 1 with grade 4 Guillain-Barré syndrome. Thirty patients (48.4%) experienced grade 3 or higher treatment-related adverse events. Conclusions and Relevance These findings suggest that neoadjuvant atezolizumab merits further study based on safety and encouraging outcomes. Trial Registration ClinicalTrials.gov Identifier: NCT03102242

TPS8123 Background: A minority of patients with unresectable stage III non-small cell lung cancer (NSCLC) may be cured by chemoradiotherapy (CRT). Adjuvant checkpoint inhibition through PD-L1 blockade after CRT improved survival compared to placebo in the PACIFIC trial (median progression-free survival (mPFS) 16.9 vs 5.6 months (mo), median overall survival (mOS) 47.5 vs 29.1 mo), but overall survival at 5 years remains below 50% (Spigel D, et al J Clin Oncol 2022, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9015199/ . Only patients completing CRT without progression and with good performance status were eligible for this approach. Neoadjuvant checkpoint inhibition would allow more patients the opportunity to benefit from immunotherapy and may attenuate tumor-related immunosuppression via depletion of regulatory T cells and clonal expansion of effector T cells, thereby improving tumor immunogenicity. Neoadjuvant atezolizumab had favorable outcomes compared to historic PACIFIC data in the phase II single arm trial, AFT-16 (mPFS 30 mo and mOS not reached). Whether combination immunotherapy therapy before CRT will improve outcomes in this setting is the question posed in the AFT-57 trial. Methods: This phase II randomized Alliance Foundation Trials study (AFT-57) will evaluate safety and efficacy of atezolizumab with or without the anti-TIGIT monoclonal antibody, tiragolumab, before and after definitive CRT with concurrent atezolizumab. The primary endpoint is PFS in the two experimental arms with a goal to select the most promising regimen for further study. AFT-57 will randomly assign 158 patients with stage III NSCLC (AJCC v8), Eastern Cooperative Oncology Group performance status 0-1, no active autoimmune disease and no underlying organ dysfunction to 2 cycles of neoadjuvant atezolizumab (1200 mg intravenously [IV] every 21 days) with or without tiragolumab (600 mg IV). Non-progressing patients will receive carboplatin and paclitaxel weekly with atezolizumab 1200 mg IV every 21 days concurrent with 60 Gray involved field thoracic radiation in 30 daily fractions (Monday - Friday) followed by atezolizumab with or without tiragolumab on the same schedule as the neoadjuvant doses, with a plan to complete one year of therapy. A pilot cohort of 20 patients for whom tiragolumab will be combined with atezolizumab during chemoradiotherapy is planned toward the end of accrual. Correlative science includes tissue and blood-based immune-related biomarkers at baseline and during therapy. This trial utilizes the Alliance Participant Engagement Portal, a patient-facing site designed to provide information and resources to Alliance clinical trial participants. The trial was activated on 12/7/23 with the first patient screened 1/19/24. Clinical trial information: NCT05798663 .

AbstractIntroductionIncreasingly, early‐stage non–small cell lung cancer (NSCLC) is treated with stereotactic body radiation therapy (SBRT). Although treatment is generally effective, a small subset of tumors will recur because of radioresistance. Preclinical studies suggested PI3K‐AKT‐mTOR activation mediates radioresistance. This study sought to validate this finding in tumor samples from patients who underwent SBRT for NSCLC.MethodsPatients with T1‐3N0 NSCLC treated with SBRT at our institution were included. Total RNA of formalin‐fixed paraffin‐embedded tumor biopsy specimens (pretherapy) was isolated and analyzed using the Clariom D assay. Risk scores from a PI3K activity signature and four published NSCLC signatures were generated and dichotomized by the median. Kaplan–Meier curves and Cox regressions were used to analyze their association with recurrence and overall survival (OS). The PI3K signature was also tested in a data set of resected NSCLC for additional validation.ResultsA total of 92 patients were included, with a median follow‐up of 18.3 months for living patients. There was no association of any of the four published gene expression signatures with recurrence or OS. However, high PI3K risk score was associated with higher local recurrence (hazard ratio [HR], 11.72; 95% CI, 1.40–98.0; p = .023) and worse disease‐free survival (DFS) (HR, 3.98; 95% CI, 1.57–10.09; p = .0035), but not OS (p = .49), regional recurrence (p = .15), or distant recurrence (p = .85). In the resected NSCLC data set (n = 361), high PI3K risk score was associated with decreased OS (log‐rank p = .013) but not DFS (p = 0.54).ConclusionsThis study validates that higher PI3K activity, measured by gene expression, is associated with local recurrence and worse DFS in early‐stage NSCLC patients treated with SBRT. This may be useful in prognostication and/or tailoring treatment, and merits further validation.

Importance National guidelines endorse treatment with neoadjuvant therapy for borderline resectable pancreatic ductal adenocarcinoma (PDAC), but the optimal strategy remains unclear. Objective To compare treatment with neoadjuvant modified FOLFIRINOX (mFOLFIRINOX) with or without hypofractionated radiation therapy with historical data and establish standards for therapy in borderline resectable PDAC. Design, Setting, and Participants This prospective, multicenter, randomized phase 2 clinical trial conducted from February 2017 to January 2019 among member institutions of National Clinical Trials Network cooperative groups used standardized quality control measures and included 126 patients, of whom 70 (55.6%) were registered to arm 1 (systemic therapy; 54 randomized, 16 following closure of arm 2 at interim analysis) and 56 (44.4%) to arm 2 (systemic therapy and sequential hypofractionated radiotherapy; all randomized before closure). Data were analyzed by the Alliance Statistics and Data Management Center during September 2021. Interventions Arm 1: 8 treatment cycles of mFOLFIRINOX (oxaliplatin, 85 mg/m 2 ; irinotecan, 180 mg/m 2 ; leucovorin, 400 mg/m 2 ; and infusional fluorouracil, 2400 mg/m 2 ) over 46 hours, administered every 2 weeks. Arm 2: 7 treatment cycles of mFOLFIRINOX followed by stereotactic body radiotherapy (33-40 Gy in 5 fractions) or hypofractionated image-guided radiotherapy (25 Gy in 5 fractions). Patients without disease progression underwent pancreatectomy, which was followed by 4 cycles of treatment with postoperative FOLFOX6 (oxaliplatin, 85 mg/m 2 ; leucovorin, 400 mg/m 2 ; bolus fluorouracil, 400 mg/m 2 ; and infusional fluorouracil, 2400 mg/m 2 over 46 hours). Main Outcomes and Measures Each treatment arm’s 18-month overall survival (OS) rate was compared with a historical control rate of 50%. A planned interim analysis mandated closure of either arm for which 11 or fewer of the first 30 accrued patients underwent margin-negative (R0) resection. Results Of 126 patients, 62 (49%) were women, and the median (range) age was 64 (37-83) years. Among the first 30 evaluable patients enrolled to each arm, 17 patients in arm 1 (57%) and 10 patients in arm 2 (33%) had undergone R0 resection, leading to closure of arm 2 but continuation to full enrollment in arm 1. The 18-month OS rate of evaluable patients was 66.7% (95% CI, 56.1%-79.4%) in arm 1 and 47.3% (95% CI 35.8%-62.5%) in arm 2. The median OS of evaluable patients in arm 1 and arm 2 was 29.8 (95% CI, 21.1-36.6) months and 17.1 (95% CI, 12.8-24.4) months, respectively. Conclusions and Relevance This randomized clinical trial found that treatment with neoadjuvant mFOLFIRINOX alone was associated with favorable OS in patients with borderline resectable PDAC compared with mFOLFIRINOX treatment plus hypofractionated radiotherapy; thus, mFOLFIRINOX represents a reference regimen in this setting. Trial Registration ClinicalTrials.gov Identifier: NCT02839343

Background: Optimal patient selection for radiotherapy in pancreatic ductal adenocarcinoma (PDAC) is unestablished. Molecular profiling may select patients at high risk for locoregional recurrence (LRR) who would benefit from radiation. Methods: We included resectable pancreatic cancer (R-PDAC) patients, divided into training and validation cohorts, treated among three institutions with surgery and adjuvant chemotherapy, and borderline resectable or locally advanced pancreatic cancer (BR/LA-PDAC) patients treated with chemotherapy with or without radiation at the primary study institution. We isolated RNA from R-PDAC surgical specimens. Using NanoString, we identified miRNAs differentially expressed between normal and malignant pancreatic tissue. ElasticNet regression identified two miRNAs most predictive of LRR in the training cohort, miR-181b/d and miR-575, which were used to generate a risk score (RS). We evaluated the association of the median-dichotomized RS with recurrence and overall survival (OS). Results: We identified 183 R-PDAC and 77 BR/LA-PDAC patients with median follow up of 37 months treated between 2001 and 2014. On multivariable analysis of the R-PDAC training cohort (n = 90), RS was associated with worse LRR (HR = 1.34; 95%CI 1.27–11.38; p = 0.017) and OS (HR = 2.89; 95%CI 1.10–4.76; p = 0.027). In the R-PDAC validation cohort, RS was associated with worse LRR (HR = 2.39; 95%CI 1.03–5.54; p = 0.042), but not OS (p = 0.087). For BR/LA-PDAC, RS was associated with worse LRR (HR = 2.71; 95%CI 1.14–6.48; p = 0.025), DR (HR = 1.93; 95%CI 1.10–3.38; p = 0.022), and OS (HR = 1.97; 95%CI 1.17–3.34; p = 0.011). Additionally, after stratifying by RS and receipt of radiation in BR/LA-PDAC patients, high RS patients who did not receive radiation had worse LRR (p = 0.018), DR (p = 0.006), and OS (p < 0.001) compared to patients with either low RS or patients who received radiation, irrespective of RS. Conclusions: RS predicted worse LRR and OS in R-PDAC and worse LRR, DR, and OS in BR/LA-PDAC. This may select patients who would benefit from radiation and should be validated prospectively.

Abstract KRAS-activating mutations are oncogenic drivers and are correlated with radioresistance of multiple cancers, including colorectal cancer, but the underlying precise molecular mechanisms remain elusive. Herein we model the radiosensitivity of isogenic HCT116 and SW48 colorectal cancer cell lines bearing wild-type or various mutant KRAS isoforms. We demonstrate that KRAS mutations indeed lead to radioresistance accompanied by reduced radiotherapy-induced mitotic catastrophe and an accelerated release from G2/M arrest. Moreover, KRAS mutations result in increased DNA damage response and upregulation of 53BP1 with associated increased non-homologous end-joining (NHEJ) repair. Remarkably, KRAS mutations lead to activation of NRF2 antioxidant signaling to increase 53BP1 gene transcription. Furthermore, genetic silencing or pharmacological inhibition of KRAS, NRF2 or 53BP1 attenuates KRAS mutation-induced radioresistance, especially in G1 phase cells. These findings reveal an important role for a KRAS-induced NRF2-53BP1 axis in the DNA repair and survival of KRAS-mutant tumor cells after radiotherapy, and indicate that targeting NRF2, 53BP1 or NHEJ may represent novel strategies to selectively abrogate KRAS mutation-mediated radioresistance.

TPS4168 Background: Metastatic pancreatic adenocarcinoma has a poor prognosis, and improvements in therapy have been challenging. Alongside efforts in developing novel agents, there is a need to optimize and maximize the benefit of currently approved drugs. Gemcitabine + nab-paclitaxel is a frequently used regimen for pancreatic adenocarcinoma. Nab-paclitaxel is albumin–bound chemotherapy; hence the role of albumin uptake is critical for its effect. Caveolae are small membrane invaginations essential for transendothelial albumin uptake. Cav-1 is the principal structural component of caveolae. Williams and colleagues have published a series of preclinical studies demonstrating that tumor cell-specific Cav-1 expression directly correlates with albumin and albumin-bound chemotherapy uptake and subsequent apoptotic response in tumor cells. In vitro studies showed that exposure of pancreatic cancer cells to Gemcitabine resulted in up-regulation of Cav-1 peaking 48 hours after gemcitabine exposure. This Cav-1 up-regulation correlated with increased temporal albumin cellular uptake. In addition, Williams and colleagues noted that exposure of pancreatic cancer cell lines to Gemcitabine resulted in a time–specific re-entry of cells into the G2/M phase (nab-paclitaxel cytotoxicity phase) between 48-60 hours after gemcitabine treatment. Collectively this data suggest that infusing nab-paclitaxel after 48 hours of gemcitabine infusion would be optimal for both increased uptake as well as increased susceptible tumor cells. We had previously shown this effect on multiple cell lines as well as mouse models. Methods: This is a phase II trial; patients will receive a standard of care chemotherapy regimen consisting of FDA-approved Gemcitabine + nab-paclitaxel with modification of the schedule to deliver nab-paclitaxel 48 hours (2 days) after gemcitabine infusions. The primary endpoint is ORR, with a null hypothesis of 20% vs. a target of 35%. Employing a 2-stage design (minimax) and assuming 80% power and a 0.05 significance level, a total of 53 patients will be required. In the first stage, if at least 7/31 patients respond to therapy, an additional 22 patients will be added for a total of 53 patients. The study will be terminated early if ≤ six patients respond in the first stage. Observation of response in at least 16/53 patients would be required to warrant further investigation of this infusion schedule of combination therapy. The secondary endpoints include the safety of the regimen schedule, Relative dose intensity, disease control rate, PFS, and OS. The trial opened to enrollment in June 2020 and is accepting patients. Clinical trial information: NCT04115163.

377 Background: Neoadjuvant therapy has been associated with a median overall survival (OS) of 18 – 23 months (mo) in patients (pts) with BR pancreatic ductal adenocarcinoma (PDAC). To establish reference regimens to which novel treatments can be compared in future studies, we evaluated neoadjuvant mFOLFIRINOX with or without RT in BR PDAC in a phase II National Clinical Trials Network (NCTN) trial. Methods: Pts with ECOG PS 0-1 and BR PDAC confirmed by central real-time radiographic review after pre-registration were randomized to either arm A: 8 cycles of neoadjuvant mFOLFIRINOX (oxaliplatin 85 mg/m2, irinotecan 180 mg/m2, leucovorin 400 mg/m2 and infusional 5-fluorouracil 2400 mg/m2 over 46 hours), or arm B: 7 cycles of mFOLFIRINOX followed by stereotactic body RT (SBRT, 33-40 Gy in 5 fractions [fx]) or hypofractionated image guided RT (HIGRT, 25 Gy in 5 fx). Pts in either arm without disease progression underwent pancreatectomy, then 4 cycles of adjuvant mFOLFOX6 (oxaliplatin 85 mg/m2, leucovorin 400 mg/m2 and infusional 5-fluorouracil 2400 mg/m2 over 46 hours). The primary endpoint, 18-mo OS rate, of each arm was compared to a historical control of 50%. Planned interim analysis mandated closure of either arm in which <11 of first 30 accrued pts underwent R0 resection. Results: 155 pts pre-registered and 126 pts were enrolled to arm A (N=70; 54 randomized, 16 following closure of arm B) or arm B (N=56; closed at interim analysis, all pts randomized prior to closure). Median age (A: 63y, B: 67y), median CA 19-9 level (A: 171 U/ml, B: 248 U/ml) and ECOG PS (A: 51% PS 0, B: 57% PS 0) of registered pts were similar between arms (p > 0.05). Treatment detailed in Table. The 18-mo OS rate based on Kaplan Meier estimates was 67.9% (95%CI: 54.6 – 78.0) in arm A and 47.3% (95%CI: 33.7 – 59.7) in arm B. Among pts who underwent pancreatectomy, 18-mo OS rate was 93.1% (95%CI: 84.3 – 100) and 78.9% (95%CI: 62.6 – 99.6) in arm A and B, respectively. With median follow-up of 27 and 31 mo, median OS was 31.0 (95%CI: 22.2 – NE) mo and 17.1 (95%CI: 12.8 – 24.4) mo in arm A and B, respectively. Conclusions: Neoadjuvant mFOLFIRINOX was associated with favorable OS relative to historical data in pts with BL PDAC in this phase II NCTN trial. mFOLFIRINOX with hypofractionated RT did not improve OS compared to historical data. mFOLFIRINOX represents a reference regimen in this setting and a backbone on which to add novel agents. Support: U10CA180821, U10CA180882, U24CA196171; https://acknowledgments.alliancefound.org Clinical trial information: NCT02839343. [Table: see text]