Citations

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.

413 Background: Vascular endothelial growth factor (VEGF) and VEGF receptor (VEGFR)-mediated signaling and angiogenesis contribute to the pathogenesis and progression of pancreatic adenocarcinoma (PCA).VEGF is expressed in all PCA tumors. VEGF-A/VEGFR-2 signaling plays an important role in inducing invasion and migration of PCA cells. The pVEGFR-2 is significantly associated with invasion of the anterior capsule of pancreas and arteries. In preclinical studies, the anti-tumor activity of fluoropyrimidines, but not that of gemcitabine, caused the release of bone marrow derived circulating endothelial progenitor cells (CEPs) and Tie-2 expressing monocytes (TEMs) as well as the induction of pro-angiogenic growth factors. Methods: This phase II randomized, multi-center, and double-blinded trial was designed to compare the efficacy and safety of mFOLFIRINOX/ramucirumab (Arm A) versus mFOLFIRINOX/ placebo (Arm B) as front-line therapy in recurrent or metastatic PCA patients. The primary endpoint was progression free survival (PFS) at 9 months, and the secondary endpoints included overall survival (OS) and response rate. Results: A total of 86 subjects were enrolled, 82 were eligible (42 in Arm A v. 40 in Arm B). The mean age of the subjects in the two arms were comparable (61.7 v. 63.0, respectively); 43 male, 69 Caucasian. On the univariate analysis, there was no difference in distribution between the 2 arms for age, gender, race and ethnicity. The median PFS was 5.6 in Arm A compared to 6.7 months in Arm B (one-sided log-rank, p = 0.322). At 9 months, the progression free rates were 25.1% v. 35% for Arms A and B, respectively. The mFOLFIRINOX/ramucirumab combination was well tolerated. Patients in Arm A reported a slightly higher number of adverse events (AEs) encounters, most commonly diarrhea (29 vs 28), fatigue (25 v. 25), vomiting (24 v. 14), weight loss (23 v. 17), and abdominal pain (20 v. 15). Arm A had more SAEs than Arm B (43 v. 25), with sepsis most commonly reported in both arms (3 in each), vomiting (3 v. 2), diarrhea (3 v.1) and duodenal obstruction (3 v. 0). Arm B had a slightly higher response rate (22.58%) compared to Arm A (17.65%) that was not statistically significant. The median OS in Arm A was 10.3 compared to 9.7 months for Arm B (one-sided log-rank, p = 0.094). Conclusions: In this randomized phase 2 study, the addition of ramucirumab to mFOLFIRINOX did not improve PFS, response rate, or OS as initial therapy for metastatic pancreatic cancer. FOLFIRINOX/Ramucirumab combination was well tolerated in the treatment of PCA. Clinical trial information: NCT02581215.

402 Background: Pancreas cancer is an aggressive malignancy with limited therapeutic options. Nanoliposomal irinotecan (Nal-IRI) is a preferred second-line treatment, and current guidelines recommend its use in the absence of prior irinotecan. This study aimed to assess whether patients who had received regular irinotecan derive benefit from Nal-IRI. Methods: Medical records of metastatic pancreas cancer patients who had received regular irinotecan and then Nal-IRI were reviewed. The following information was extracted from each medical record: patient demographics, confirmation of a diagnosis of exocrine pancreas cancer, initial cancer stage, dates of administration of the drugs of interest, adverse events that occurred with Nal-IRI treatment, reasons for stopping regular irinotecan, and reasons for starting and stopping Nal-IRI. The primary endpoint was overall survival after the initiation of Nal-IRI (an a priori threshold of > 4 months defined success). Survival data were censored based on date of last follow up. Direct quotes from the medical record were documented to provide insight on prescribing Nal-IRI when guidelines advised the contrary. Results: Sixty four patients met eligibility criteria with a median age of 65 years (range: 36, 80 years). Prior to Nal-IRI, 61 patients had received FOLFIRINOX, and 3 FOLFIRI. Of these, 32 patients manifested progressive disease on regular irinotecan-based therapy. Nal-IRI was prescribed with a fluoropyrimidine; only one patient received monotherapy. At time of analysis, 54 patients had died. Median overall survival from initiation of Nal-IRI was 5.1 months (95% confidence interval (CI): 5.6, 4.3, months). An exploratory comparison, based on no cancer progression with regular irinotecan versus progression, showed improved survival with Nal-IRI in the former group: 6.1 months (95% CI: 9.3, 5.1 months) versus 4.3 months (95% CI: 4.8, 2.3 months); p=0.0006. Nal-IRI adverse events occurred as expected. Qualitative data illustrated several themes, including “limited treatment options,” which appeared to drive the decision to prescribe Nal-IRI. Conclusions: Nal-IRI might be considered in pancreas cancer patients who had received regular irinotecan, particularly in the absence of disease progression with the latter.

348 Background: The proportion of females in medicine is increasing (approx. 50% in medical school/workforce), but disparities in female authorship in oncology research publications exist; female corresponding authorship reportedly ranges from 7.2-39.1% in oncology clinical trials (Ludmir et al 2019). This study aimed to describe and assess factors associated with female first and senior authorship in later phase systemic clinical trials in BTC and to identify any changes over time. Methods: Embase/Medline were used to identify final primary trial publications in BTC (2000-2020) (excluding phase I (PI) (expected to move to later phase), mixed tumour site trials, reviews, editorials and trial-in-progress publications). Gender was determined by inspection of names, google search and author communication. Chi-square tests and log regression were used to assess factors associated with female first and senior authorship, including changes over time (STATA16). Results: Of 501 publications, 163 met inclusion criteria; 80% single-arm PII and 15% and 5% randomised PII and PIII respectively; 73% enrolled ≤50 patients. Tumour primary sites were all BTC: 86%, cholangiocarcinoma: 8%, gallbladder cancer: 6%; 80% involved chemotherapy, 13% targeted therapy and 5% localised/systemic combinations; 65% were in first-line (1L) advanced setting, 17% post 1L, 13% advanced non-specified and 5% neo-adjuvant/adjuvant. Forty-eight percent received industry funding and 65% met primary end-point. Sixty-four percent were published post ABC-02 (Valle et al 2010). Publication impact factor (IF) was ≤5 in 50% and >20 in 12%. Median number of authors in all publications was 11. Geographic location of all first and senior authors were Asia (42%/42%), Europe (29%/29%), USA (24%/22%) and other (4%/6%), respectively. Median individual trial female author representation was 25%; there were no female authors in 12% of trials. Overall, female first and senior author representation was 21% and 11%, respectively. Median position of first female author was second. In publications with IF ≤20 and >20, there were 22% and 16% female first and 13% and 0% female senior authors, respectively. The phase of trial, journal IF, industry funding, or whether met primary end-point did not impact female first or senior author representation (all P>.05). There were more female senior authors associated with “other” geographic locations (40% in 10 trials) (P=.016) vs Asia (7%), Europe (8%) and USA (14%). There were no significant changes in female first or senior author representation over time (‘00-05: 21%/18%, ‘06-10: 27%/5%, ‘11-15: 15%/15%, ‘16-20: 22%/9%, P=.738, and P=.508 respectively). Conclusions: Female first and senior author representation in later phase systemic clinical trial publications in BTC is low and has not changed significantly over time. The underlying reasons for this imbalance need to be better understood and addressed.

Over the past 20 years, management of patients with metastatic colorectal cancer (mCRC) has improved considerably, leading to increased overall survival and more patients eligible for third- or later-line therapy. Currently, two oral therapies are recommended in the third-line treatment of mCRC, regorafenib and trifluridine/tipiracil. Selecting the most appropriate treatment in the third-line setting poses different challenges compared with treatment selection at earlier stages. Therefore, it is important for physicians to understand and differentiate between available treatment options and to communicate the benefits and challenges of these to patients. In this narrative review, practical information on regorafenib is provided to aid physicians in their decision-making and patient communications in daily practice. We discuss the importance of appropriate patient selection and adverse events management through close patient monitoring and dose adjustments to ensure patients stay on treatment for longer and receive as much benefit as possible. We also highlight key physician–patient communication points to facilitate shared decision-making.

Abstract Background: Chemotherapy in combination with targeted agents are standard-of-care options for patients for mCRC with response rates >50% in first line. In the second line setting, efficacy of chemotherapy and targeted agents are much lower with response rates of 5% for FOLFIRI (5-fluorouracil, leucovorin, irinotecan) + bevacizumab (anti-VEGF). New treatment options are urgently needed in particular for the 50 % of patients harboring a KRAS mutation. Polo-like kinase 1 (PLK1) is a serine/threonine kinase, master regulator of the mitotic checkpoint and cell division. PLK1 is overexpressed in CRC and its overexpression is associated with poor prognostic. A genome wide RNAi screen identified PLK1 as a synthetic lethal target in KRAS mutant CRC cells, inducing cell cycle arrest and apoptosis upon inhibition. Onvansertib is an oral, highly selective PLK1 inhibitor that demonstrates single agent and synergistic activity with irinotecan in preclinical CRC models. Additionally, KRAS mutated vs wild-type cells showed higher sensitivity to onvansertib. PLK1 inhibition is a potential target in KRAS-mutated mCRC and onvansertib + FOLFIRI + bevacizumab may provide a new second-line treatment option. Trial design: The primary objective of this single-arm Phase 1b/2 study is to assess the safety and preliminary efficacy of onvansertib in combination with FOLFIRI and bevacizumab in the second line setting for KRAS-mutated mCRC patients. For the Phase 1b segment, a standard 3 + 3 dose-escalation design is used to determine the maximum tolerated dose or recommended phase 2 dose (RP2D) of onvansertib. As of January 24th 2020, enrollment in the second dose level is ongoing. Efficacy will be determined by objective response rate (ORR) according to RECIST v1.1 (primary endpoint), progression-free survival and reduction in KRAS allelic burden in liquid biopsies (secondary endpoints). In the phase 2, based on a one-sided one sample log-rank test with 10% Type I error, there will be at least 90% power to detect an improvement in ORR from 5% to 20% with 26 patients. Exploratory endpoints include genomic studies of circulating tumor cells and ctDNA to evaluate altered pathways that correlate with patient response. Clinical trial identification NCT03829410. Citation Format: Afsaneh Barzi, Heinz-Josef Lenz, Errin Samuëlsz, Maya Ridinger, Mark Erlander, Tanios S. Bekaii-Saab, Daniel H. Ahn. A phase 1b/2 study of onvansertib (PCM-075) in combination with FOLFIRI and bevacizumab for second line treatment of patients with KRAS-mutated metastatic colorectal cancer (mCRC) [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT235.