Botrus, Gehan

3580 Background: TAS-102 (FTD/TPI) is a combination of a nucleoside analogue and a thymidine phosphorylase inhibitor, and has showed activity in 5FU-resistant CRC. Nal-IRI achieves higher intra-tumor concentrations than irinotecan (Iri; 142-fold) and its major metabolite, SN-38 (9-fold). This resulted in superior anti-tumor activity compared to free Iri in multiple tumor xenografts. Furthermore, multiple clinical trials have established the activity of nal-IRI in combination with 5FU in pancreaticobiliary cancers. The combination of nal-IRI with the more potent nucleoside analogue TAS-102 may thus result in a more effective systemic therapy. We conducted this study to define the safety and efficacy of the combination of TAS-102 and nal-IRI in advanced CRC. Methods: Eligible patients (pts) on this investigator-initiated phase II study had advanced CRC and must have had disease progression on at least one prior therapy. Additional inclusion criteria - measurable disease, ECOG PS 0-1 & adequate organ function. Based on previously published dose escalation phase I data, the pts were treated at the recommended phase II dose of TAS-102 (given orally at 35mg/m2 bid on days 1-5) and nal-IRI (60mg/m2 IV on day 1) in 14-day cycles. The primary endpoint was objective response rate (ORR) = complete (CR) + partial (PR) response per RECIST v1.1. Multiple secondary endpoints included safety/tolerability, progression-free survival (PFS), overall survival (OS), disease control rate (DCR) and duration of response (DoR). Results: Twenty-two pts were enrolled, of whom 20 were evaluable for response. Male - 50%; ECOG PS 1 – 75%; African Americans – 38%; median age - 58yrs (interquartile range [IQR] 49-67). Median line of prior therapy was 1 (IQR 1-2) and 13.6% (3 pts enrolled during the dose escalation phase) had received prior Iri. 47.6% received concurrent Bevacizumab. ORR was 15% (3 PR, 0 CR). 60% had stable disease (SD) as best response; DCR of 75%. mPFS - 9.7 mos (95% CI: 5.6, 14.2); mOS - 10.1 mos (95% CI: 7.3, 15.9). 12-month PFS and OS rates were 34.6% and 39.5% respectively. At a median follow up of 11.9 mos, DoR was yet to be determined and 50% of the pts had maintained response for 12 mos. Median duration of progression free among pts with SD was 7.6 mos (95% CI: 4.6, 13.2), with a 12-month survival rate of 47.7% (95% CI: 15.5%, 74.5%). Median time to response (TTR) was 4.8mos. Most common treatment related toxicities included fatigue and neutropenia (G3; 27.3% each); anemia and leucopenia (G3; 18.2% each). Other G3 AEs included febrile neutropenia, diarrhea, hypokalemia, lymphopenia and nausea (4.5% each). Conclusions: We demonstrated that the combination of TAS-102 and nal-IRI had an acceptable safety profile, and showed antitumor activity in patients with advanced CRC. Additional biomarker analyses such as survival correlation with UGT1A1 phenotype and RAS mutational status are ongoing. (NCT03368963). Clinical trial information: NCT03368963 .

Abstract Background Despite multiple randomized trials, the role of perioperative chemotherapy in colorectal cancer liver metastasis (CRLM) is still under debate. In this systematic review and network meta-analysis (NMA), we aim to evaluate the efficacy of perioperative systemic therapies for patients with CRLM. Methods We searched various databases for abstracts and full-text articles published from database inception through May 2021.We included randomized controlled trials (RCTs) comparing the addition of perioperative (post, pre, or both) systemic therapies to surgery alone in patients with CRLM. The outcomes were compared according to the chemotherapy regimen using a random effects model. Outcomes of interest included disease-free survival (DFS) and overall survival (OS). Results Seven RCTs with a total of 1504 patients with CRLM were included. Six studies included post-operative treatment and one evaluated perioperative (pre- and postoperative) therapy. Fluoropyrimidine-based chemotherapy was the most used systemic therapy. NMA showed benefit of adding perioperative therapy to surgery in terms of DFS (HR 0.73, 95% CI 0.63 to 0.84). However, these findings did not translate into a statistically significant OS benefit (HR 0.88, 95% CI 0.74 to 1.05). NMA did not show any advantage of one regimen over another including oxaliplatin or irinotecan. Conclusions This systematic review and NMA of 7 RCTs found that the addition of perioperative systemic treatment for resectable CRLM could improve disease-free survival but not overall survival. Based on the findings, addition of perioperative treatment in resectable CRLM should be individualized weighing the risks and benefits.

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.

TPS4181 Background: The mainstay of treatment (TX) for pts with advanced or mPDAC consists of CT, with FOLFIRINOX and gemcitabine (gem)/nab-paclitaxel currently representing the front-line standards of care. TX is generally continued until either dis progression (progr) or cumulative toxicity, with pts often reaching a plateau in response after 4-6 mos. For those who have achieved dis control (stable dis or better) on front-line CT, a maint TX strategy that can effectively delay dis progr while preserving quality of life with minimal cumulative toxicity is highly desirable. However, aside from PARP inhibition in the subset of PDAC pts with gBRCA mutated dis, there is no current standard of care in this maint setting. Ival is a pan-HDAC (histone deacetylation) inhibitor that increases histone acetylation (HA), suppresses PDAC cell proliferation, and promotes apoptosis in PDAC cell lines in a dose-dependent manner. It has demonstrated synergy with 5-FU in cholangiocarcinoma cell lines and shows promising antitumor activity when combined with cap in syngeneic PDAC mouse models. On these bases, we are conducting a ph1b/randomized ph2 trial of ival plus cap vs cap alone in the maint setting for pts with mPDAC who have not progressed on front-line FOLFIRINOX. Methods: Key eligibility criteria include pts with mPDAC; no evidence of dis progr following at least 16 wks of front-line FOLFIRINOX at full or modified doses; ECOG PS 0-1; and no known gBRCA1/2 mutation. The study includes an initial dose-esc ph1b evaluating 3 dose levels of ival, (60, 125, and 250mg/m2 iv weekly on days 1 and 8) in combination (comb) with cap (1000mg/m2 po BID on days 1-14) of a 21-day cycle, using a standard 3 + 3 dose-esc design. Of note, ival 250 mg/m2 represents the RP2D identified in prior clinical studies of this agent both as monotherapy in solid tumors and in comb with gem/erlotinib in advanced PDAC pts. In the ph2 portion, pts will be randomized 1:1 to receive either ival plus cap or cap alone, in 21-day cycles, until dis progr, with tumor assessments occurring at 6-wk intervals. Blood will be collected at pre-specified serial timepoints for pharmacodynamic assessments, including HA of PBMCs. Primary endpoint for ph2 is investigator-adjudicated PFS. The primary analysis will compare PFS distributions in the ival/cap and cap alone arms using a one-sided log rank test with an alpha = 0.10. The assumed true 6-mo PFS rates are 35% (cap), based on historic data, and 60% (ival/cap), which corresponds to an HR of 0.487. Assuming an accrual duration of 18 mos and a dropout/lost to follow-up rate of 10%, the estimated total number of pts in the randomized ph2 portion is 52 (26 per arm). Enrollment is expected to being in spring 2022 across 25 U.S. sites.

PURPOSE This investigation sought to evaluate the prognostic value of pretreatment of circulating tumor DNA (ctDNA) in metastatic biliary tract cancers (BTCs) treated with platinum-based first-line chemotherapy treatment. MATERIALS AND METHODS We performed a retrospective analysis of 67 patients who underwent ctDNA testing before platinum-based chemotherapy for first-line treatment for metastatic BTC. For analysis, we considered the detected gene with highest variant allele frequency as the dominant clone allele frequency (DCAF). Results of ctDNA analysis were correlated with patients' demographics, progression-free survival (PFS), and overall survival (OS). RESULTS The median age of patients was 67 (27-90) years. Fifty-four (80.6%) of 67 patients evaluated had intrahepatic cholangiocarcinoma; seven had extrahepatic cholangiocarcinoma, and six gallbladder cancers. Forty-six (68.6%) of the patients were treated with cisplatin plus gemcitabine, and 16.4% of patients received gemcitabine and other platinum (carboplatin or oxaliplatin) combinations, whereas 15% of patients were treated on a clinical trial with gemcitabine and cisplatin plus additional agents (CX4945, PEGPH20, or nab-paclitaxel). TP53, KRAS, FGFR2, ARID1A, STK11, and IDH1 were the genes with highest frequency as DCAF. The median DCAF was 3% (0%-97%). DCAF > 3% was associated with worse OS (median OS: 10.8 v 18.8 months, P = .032). Stratifying DCAF in quartiles, DCAF > 10% was significantly related to worse PFS (median PFS: 3 months, P = .014) and worse OS (median OS: 7.0 months, P = .001). Each 1% increase in ctDNA was associated with a hazard ratio of 13.1 in OS when adjusting for subtypes, metastatic sites, size of largest tumor, age, sex, and CA19-9. CONCLUSION DCAF at diagnosis of advanced BTC can stratify patients who have worse outcomes when treated with upfront platinum-based chemotherapy. Each increase in %ctDNA decreases survival probabilities.

4130 Background: Circulating cell-free tumor DNA (ctDNA) genomic profiling is an emerging tool for pancreatic cancer. The impact of detected genomic alterations in tumor response to systemic treatments and outcomes is under investigation. Methods: Patients with advanced pancreatic cancer and ctDNA collected at time of initial diagnosis were retrospectively evaluated. Results of ctDNA analysis were correlated with patients’ demographics, systemic treatment response, progression-free survival (PFS) and overall survival (OS). Results: A total of 104 patients were included in the analysis. The mean age was 70.5 years (SD: 8.3), 50% were male, 37% with locally advanced disease and 63% with metastatic disease. Somatic alterations were detected in 84.6 % of the patients, no genetic alterations were detected in 15.4%, and were associated more with locally advanced pancreatic cancer as opposed to metastatic, p = 0.025. 60.6 % of the cohort had ≥ 2 genomic alterations detected. 28% were treated with FOLFIRINOX and 63% with gemcitabine plus nab-paclitaxel as first-line systemic treatment. Patients with any detectable genomic alterations when compared to patients with no detectable variant had worse median PFS (6.2 versus 15.3 months, p = 0.005) and patients with ≥ 2 detectable genomic alterations had worse median PFS (5.6 versus 11.0 months, p < 0.001) and worse median OS (11.5 versus 24.2 months, p = 0.001). KRAS was detected in 62.5% of the patients and was associated with PD to systemic treatments (80.4% vs 19.6%, p = 0.006), worse median PFS (5.8 versus 13.0 months, p < 0.001) and worse median OS (11.5 versus 26.3 months, p = 0.002). TP53 was detected in 60% of patients and was associated with worse median PFS (5.9 versus 10.9 months, p = 0.02) and worse median OS (13.5 versus 24.2 months, p = 0.001). CCND2 was detected in 14% of the patients and was associated with worse median PFS (3.6 versus 8.2 months, p = 0.004). Conclusions: Our study showed that initial detection of ctDNA may identify different genomic alterations that help predict disease outcomes, confirmation of these findings in larger studies are warranted.

Abstract Purpose Recent advances in molecular diagnostic technologies allow for the evaluation of solid tumor malignancies through noninvasive blood sampling, including circulating tumor DNA profiling (ctDNA). Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis, often because of late presentation of disease. Diagnosis is often made using endoscopic ultrasound or endoscopic retrograde cholangiopancreatography, which often does not yield enough tissue for next-generation sequencing. With this study, we sought to characterize the ctDNA genomic alteration landscape in patients with advanced PDAC with a focus on actionable findings. Materials and Methods From December 2014 through October 2019, 357 samples collected from 282 patients with PDAC at Mayo Clinic underwent ctDNA testing using a clinically available assay. The majority of samples were tested using the 73-gene panel which includes somatic genomic targets, including complete or critical exon coverage in 30 and 40 genes, respectively, and in some, amplifications, fusions, and indels. Clinical data and outcome variables were available for 165 patients; with 104 patients at initial presentation. Results All patients included in this study had locally advanced or metastatic PDAC. Samples having at least one alteration, when variants of unknown significance (VUS) were excluded, numbered 266 (75%). After excluding VUS, therapeutically relevant alterations were observed in 170 (48%) of the total 357 cohort, including KRAS (G12C), EGFR, ATM, MYC, BRCA, PIK3CA, and BRAF mutations. KRAS, SMAD, CCND2, or TP53 alterations were seen in higher frequency in patients with advanced disease. Conclusion Our study is the largest cohort to date that demonstrates the feasibility of ctDNA testing in PDAC. We provide a benchmark landscape upon which the field can continue to grow. Future applications may include use of ctDNA to guide treatment and serial monitoring of ctDNA during disease course to identify novel therapeutic targets for improved prognosis. Implications for Practice Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis often due to late presentation of disease. Biopsy tissue sampling is invasive and samples are often inadequate, requiring repeated invasive procedures and delays in treatment. Noninvasive methods to identify PDAC early in its course may improve prognosis in PDAC. Using ctDNA, targetable genes can be identified and used for treatment.

423 Background: Advanced PDAC remains a deadly disease with a 5-year survival rate of less than 10%. cfDNA - based next generation sequencing (NGS) may identify actionable alterations in patients with PDAC. In this study, we aim to determine the feasibility of utilizing serial cfDNA NGS testing and its potential relevance in predicting therapeutics outcomes. Methods: A total of 23 PDAC patients with PDAC cfDNA isolated from plasma collected at diagnosis and upon disease progression to first line SOC therapy and were analyzed on a 73-74 gene NGS panel (Guardant Health). Changes in molecular profiles from baseline to progression were analyzed for overall survival, progression free survival (PFS), and treatment response. PFS and OS were analyzed using the Kaplan-Meier method and the log-rank test was used to compare the survival of different groups of patients. All p-values were two-sided. Analyses were performed using R (version 3.5.1, R Foundation, Vienna, Austria). Results: In this retrospective study, the 1-year probability of survival was 71% (median 473 days) and the 1-year PFS was 14% (median 212 days). TP53 and KRAS were the most frequently mutated genes identified in baseline samples, with 78% prevalence for each. Patients with clearance of TP53 17% (3/18) patients and/or KRAS 33% (6/18) patients clones after first line therapy significantly increases PFS (p=0.0056 and p=0.037, with HR of 0.087 and 0.32, respectively). However, appearance of TP53 or KRAS alterations upon progression does not significantly affect overall survival or PFS. Conclusions: The preliminary results from this study suggest that cfDNA clearance of TP53 and/or KRAS alterations may predict for improved PFS in PDAC. Confirmation of these findings in larger studies is warranted.