Darren Cowzer

Dr. Darren Cowzer

orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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29 October 2023 in Journal for ImmunoTherapy of Cancer
Verified
Journal Article
Open access
PDF file
PMPatrick T Magahis
Patrick T Magahis
SMSteven B Maron
Steven B Maron
DCDarren Cowzer
Darren Cowzer
SKStephanie King
Stephanie King
MSMark Schattner
Mark Schattner
MLMonika Laszkowska
Monika Laszkowska
Background: Gut microbiota composition can influence cancer immunotherapy response. Recent evidence suggests Helicobacter pylori infection may reduce immune checkpoint inhibitor (ICI) efficacy in lung cancer and melanoma, but thorough characterization of this association in patients with gastric cancer is lacking. We aimed to determine the impact of H. pylori on survival in this population. Methods: This single-center, retrospective study included all ICI-treated individuals with metastatic gastric cancer and documented H. pylori status at Memorial Sloan Kettering between July 2013 and October 2021. H. pylori-positive status was defined as history of infection obtained via breath test, stool antigen test, histopathology, and/or chart documentation. Negative status was defined as explicitly negative testing, histopathology, and/or chart documentation. Primary outcomes were progression-free survival (PFS) and overall survival (OS). Results: Of 215 included patients, 49 had documented history of H. pylori infection. Compared with H. pylori-negative patients, positive individuals tended to be younger, non-white, and Hispanic with non-cardia and intestinal-type gastric cancer. H. pylori-positive patients had significantly shorter median PFS (3.2 vs 6.8 months, HR 1.96, p<0.01) and OS (9.8 vs 17.9 months, HR 1.54, p=0.02). Multivariable analysis confirmed H. pylori infection as an independent predictor of PFS (HR 3.04, p<0.01) and OS (HR 2.24, p=0.01). Conclusions: In this largest study of its kind, H. pylori infection was associated with inferior survival in ICI-treated patients with gastric cancer. This suggests H. pylori status may be a prognostic marker of immune responsiveness. Future studies are needed to elucidate immunoregulatory mechanisms and whether treatment of active infections would improve immunotherapy outcomes.

Verified
Journal Article
Open access
PDF file
DCDarren Cowzer
Darren Cowzer
MZMohammed Zameer
Mohammed Zameer
MCMichael Conroy
Michael Conroy
Walter KolchWalter Kolch
Walter Kolch
ADAustin Duffy
Austin Duffy
Pancreatic cancer is mainly driven by mutations in the KRAS oncogene. While this cancer has shown remarkable therapy resistance, new approaches to inhibit mutated KRAS, KRAS activators and effectors show promise in breaking this therapeutic deadlock. Here, we review these innovations in therapies that target RAS signaling in pancreatic cancer from a clinical point of view. A number of promising approaches are currently in clinical trials or in clinical development. We focus on small-molecule drugs but also discuss immunotherapies and tumor vaccines.

5 June 2023 in Journal for ImmunoTherapy of Cancer
Verified
Journal Article
Open access
PDF file
GRGiovanni Randon
Giovanni Randon
YAYu Aoki
Yu Aoki
RCRomain Cohen
Romain Cohen
LPLeonardo Provenzano
Leonardo Provenzano
VNVincenzo Nasca
Vincenzo Nasca
FPFilippo Pietrantonio
Filippo Pietrantonio
Background Subgroup analyses of randomized trials suggest the superiority of immune checkpoint inhibitor-based therapy over chemotherapy in patients with mismatch-repair deficient (dMMR) and/or microsatellite instability-high (MSI-high) advanced gastric or gastroesophageal junction adenocarcinoma. However, these subgroups are small and studies examining prognostic features within dMMR/MSI-high patients are lacking. Methods We conducted an international cohort study at tertiary cancer centers and collected baseline clinicopathologic features of patients with dMMR/MSI-high metastatic or unresectable gastric cancer treated with anti-programmed cell death protein-1 (PD-1)-based therapies. The adjusted HRs of variables significantly associated with overall survival (OS) were used to develop a prognostic score. Results One hundred and thirty patients were included. At a median follow-up of 25.1 months, the median progression-free survival (PFS) was 30.3 months (95% CI: 20.4 to NA) and 2-year PFS rate was 56% (95% CI: 48% to 66%). Median OS was of 62.5 months (95% CI: 28.4 to NA) and 2-year OS rate was 63% (95% CI: 55% to 73%). Among the 103 Response Evaluation Criteria in Solid Tumors-evaluable patients, objective response rate was 66% and disease control rate 87% across lines of therapy. In the multivariable models, Eastern Cooperative Oncology Group Performance Status of 1 or 2, non-resected primary tumor, presence of bone metastases and malignant ascites were independently associated with poorer PFS and OS. These four clinical variables were used to build a three-category (ie, good, intermediate, and poor risk) prognostic score. Compared with patients with good risk, patients with intermediate risk score had numerically inferior PFS and OS (2-year PFS rate: 54.3% versus 74.5%, HR 1.90, 95% CI: 0.99 to 3.66; 2-year OS rate: 66.8% versus 81.2%, HR 1.86, 95% CI: 0.87 to 3.98), whereas patients with poor risk score had significantly inferior PFS and OS (2-year PFS rate: 10.6%, HR 9.65, 95% CI: 4.67 to 19.92; 2-year OS rate: 13.3%, HR 11.93, 95% CI: 5.42 to 26.23). Conclusions Overall outcomes with anti-PD-1-based therapies are favorable in MSI-high gastroesophageal adenocarcinomas. However, within this overall favorable subgroup a more accurate prognostication using baseline clinical characteristics might identify patients at higher risk of rapid disease progression who may deserve intensified immunotherapy combination strategies.

10 February 2023 in Annals of Surgery
Verified
Journal Article
Closed access
DCDarren Cowzer
Darren Cowzer
AWAbraham Jing-Ching Wu
Abraham Jing-Ching Wu
SSSmita Sihag
Smita Sihag
HWHenry S. Walch
Henry S. Walch
BPBernard J. Park
Bernard J. Park
GKGeoffrey Y. Ku
Geoffrey Y. Ku
Objective: To determine the safety and efficacy of adding the anti-PD-L1 antibody durvalumab to induction FOLFOX and preoperative chemotherapy in locally advanced esophageal adenocarcinoma. Background: Neoadjuvant induction FOLFOX followed by positron emission tomography (PET) directed chemoradiation has demonstrated improved survival for esophageal adenocarcinoma. There is clear benefit now for the addition of immune checkpoint inhibitors both in early and advanced stage disease. Given these results we investigated the safety and efficacy of adding durvalumab to induction FOLFOX and preoperative chemoradiotherapy. Methods: Patients with locally advanced resectable esophageal/gastroesophageal junction adenocarcinoma received PET-directed chemoradiation with durvalumab before esophagectomy. Patients who had R0 resections received adjuvant durvalumab 1500 mg every 4 weeks for 6 treatments. The primary endpoint of the study was pathologic complete response. Results: We enrolled 36 patients, 33 of whom completed all preoperative treatment and underwent surgery. Preoperative treatment was well tolerated, with no delays to surgery nor new safety signals. Pathologic complete response was identified in 8 [22% (1-sided 90% lower bound: 13.3%)] patients with major pathologic response in 22 [61% (1-sided 90% lower bound: 50%)] patients. Twelve and 24-month overall survival was 92% and 85%, respectively. Conclusions: The addition of durvalumab to induction FOLFOX and PET-directed chemoradiotherapy before surgery is safe, with a high rate of pathologic response, as well as encouraging survival data.

1 September 2023 in JCO Precision Oncology
Verified
Journal Article
Closed access
DCDarren Cowzer
Darren Cowzer
JWJessica B. White
Jessica B. White
JCJoanne F. Chou
Joanne F. Chou
PCPin-Jung Chen
Pin-Jung Chen
TKTae-Hyung Kim
Tae-Hyung Kim
JHJames J. Harding
James J. Harding
NGS of cfDNA in HCC represents an alternative to tissue-based profiling, given the high tumor-plasma NGS concordance.

1 April 2022 in Cancers
Verified
Journal Article
Open access
PDF file
DCDarren Cowzer
Darren Cowzer
JHJames J Harding
James J Harding
Cancers arising in the biliary tract are rare, with varied incidence depending on geographical location. As clinical presentation is typically vague with non-specific symptoms, a large proportion of patients present with unresectable or metastatic disease at diagnosis. When unresectable, the mainstay of treatment is cytotoxic chemotherapy; however, despite this, 5-year overall survival remains incredibly poor. Diagnostic molecular pathology, using next-generation sequencing, has identified a high prevalence of targetable alterations in bile duct cancers, which is transforming care. Substantial genomic heterogeneity has been identified depending on both the anatomical location and etiology of disease, with certain alterations enriched for subtypes. In addition, immune checkpoint inhibitors with anti-PD-1/PD-L1 antibodies in combination with chemotherapy are now poised to become the standard first-line treatment option in this disease. Here, we describe the established role of cytotoxic chemotherapy, targeted precision treatments and immunotherapy in what is a rapidly evolving treatment paradigm for advanced biliary tract cancer.