Publications by authors named "Siddhartha Goutam"

5 Publications

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Outcomes of patients with solid tumour malignancies treated with first-line immuno-oncology agents who do not meet eligibility criteria for clinical trials.

Eur J Cancer 2021 Jul 8;151:115-125. Epub 2021 May 8.

Tom Baker Cancer Centre, University of Calgary, Calgary, AB, Canada. Electronic address:

Background: Immuno-oncology (IO)-based therapies have been approved based on randomised clinical trials, yet a significant proportion of real-world patients are not represented in these trials. We sought to compare the outcomes of trial-ineligible vs. -eligible patients with advanced solid tumours treated with first-line (1L) IO therapy.

Patients And Methods: Using the International Metastatic Renal Cell Carcinoma (RCC) Database Consortium and the Alberta Immunotherapy Database, patients with advanced RCC, non-small-cell lung cancer (NSCLC) or melanoma treated with 1L PD-(L)1 inhibition-based therapy were included. Trial eligibility was retrospectively determined as per commonly used exclusion criteria. The outcomes of interest were overall survival (OS), overall response rate (ORR), treatment duration (TD) and time to next treatment (TTNT).

Results: A total of 395 of 1241 (32%) patients were deemed trial-ineligible. The main reasons for ineligibility based on preselected exclusion criteria were Karnofsky performance status <70%/Eastern Cooperative Oncology Group performance status >1 (40%, 158 of 395), brain metastases (32%, 126 of 395), haemoglobin < 9 g/dL (16%, 63 of 395) and estimated glomerular filtration rate <40 mL/min (15%, 61 of 395). Between the ineligible vs. eligible groups, the median OS, ORR, median TD and median TTNT were 10.2 vs. 39.7 months (p < 0.01), 36% vs. 47% (p < 0.01), 2.7 vs. 6.9 months (p < 0.01) and 6.0 vs. 16.8 months (p < 0.01), respectively. Subgroup analyses showed statistically significant inferior OS, TD and TTNT for trial-ineligible vs. -eligible patients across all tumour types. Adjusted hazard ratios for death in RCC, NSCLC and melanoma were 1.84 (95% confidence interval [CI] 1.22-2.77), 2.21 (95% CI 1.58-3.11) and 1.82 (95% CI 1.21-2.74), respectively..

Conclusions: Thirty-two percent of real-world patients treated with contemporary 1L IO-based therapies were ineligible for clinical trials. Although one-third of the trial-ineligible patients responded to treatment, the overall trial-ineligible population had inferior outcomes than trial-eligible patients. These data may guide patient counselling and temper expectations of benefit.
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http://dx.doi.org/10.1016/j.ejca.2021.04.004DOI Listing
July 2021

Evaluation of the modified immune prognostic index to prognosticate outcomes in metastatic uveal melanoma patients treated with immune checkpoint inhibitors.

Cancer Med 2021 04 16;10(8):2618-2626. Epub 2021 Mar 16.

Tom Baker Cancer Centre, University of Calgary, Calgary, AB, Canada.

Background: Metastatic uveal melanoma (MUM) is associated with poor survival and inferior response to immune checkpoint inhibitor (ICI) therapy when compared with metastatic cutaneous melanoma. Currently, prognostic biomarkers are lacking to guide treatment decisions.

Patients And Methods: We conducted a multicenter, retrospective cohort study using a centralized, province-wide cancer database in Alberta, Canada. We identified 37 patients with histologically confirmed MUM who received at least one dose of single-agent pembrolizumab or nivolumab, or combination therapy nivolumab and ipilimumab. A modified immune prognostic index (IPI), based on the previously reported lung immune prognostic index, was used to stratify patients into favorable and poor IPI groups. Survival analyses were conducted using the Kaplan-Meier method and Cox proportional hazards models, adjusting for baseline age (≥60) and ECOG performance status, to assess the associations between IPI and overall survival (OS). Time to treatment failure (TTF) was also assessed using the Kaplan-Meier method. The association between IPI and objective response rate was examined using chi-squared tests. Logistic regression was used to determine the association between IPI and immune-related adverse events (irAEs).

Results: Median OS was 15.6 (range 0.6-57.6) months with 45.9% 1-year survival rate at a median follow-up of 11.8 months. We found that a favorable IPI was significantly associated with OS [median 30.5 (12.0-not reached) months in the favorable IPI group compared with 4.6 (2.1-16.0) months in the poor IPI group (p = 0.001)] (HR=4.81, 95% CI; 1.64-14.10, p = 0.004), TTF [median 5.1 (95% CI; 2.1-10.4) months in the favorable IPI group compared with 3.7 (95% CI; 1.4-6.4) months in the poor IPI group (p = 0.0191)], and irAE (HR=6.67, 95% CI; 1.32-33.69, p = 0.0220).

Conclusions: The modified IPI may be a useful tool in clinical practice for identifying MUM patients who are more likely to experience irAEs and realize a survival benefit from ICI treatment.
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http://dx.doi.org/10.1002/cam4.3784DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8026925PMC
April 2021

Correction: Combined poly-ADP ribose polymerase and ataxia-telangiectasia mutated/Rad3-related inhibition targets ataxia-telangiectasia mutated-deficient lung cancer cells.

Br J Cancer 2020 Jun;122(12):1872

Departments of Biochemistry and Molecular Biology, Robson DNA Science Centre and Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, T2N 1N4, Canada.

This Article was originally published under Nature Research's License to Publish, but has now been made available under a CC BY 4.0 license. This has now been corrected in both the PDF and HTML versions of the Article.
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http://dx.doi.org/10.1038/s41416-020-0841-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7283263PMC
June 2020

ATM-Deficient Cancers Provide New Opportunities for Precision Oncology.

Cancers (Basel) 2020 Mar 14;12(3). Epub 2020 Mar 14.

Department of Biochemistry and Molecular Biology, Robson DNA Science Centre, Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB T2N 1N4, Canada.

Poly-ADP ribose polymerase (PARP) inhibitors are currently used in the treatment of several cancers carrying mutations in the breast and ovarian cancer susceptibility genes and , with many more potential applications under study and in clinical trials. Here, we discuss the potential for extending PARP inhibitor therapies to tumours with deficiencies in the DNA damage-activated protein kinase, Ataxia-Telangiectasia Mutated (ATM). We highlight our recent findings that PARP inhibition alone is cytostatic but not cytotoxic in ATM-deficient cancer cells and that the combination of a PARP inhibitor with an ATR (ATM, Rad3-related) inhibitor is required to induce cell death.
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http://dx.doi.org/10.3390/cancers12030687DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7140103PMC
March 2020

Combined poly-ADP ribose polymerase and ataxia-telangiectasia mutated/Rad3-related inhibition targets ataxia-telangiectasia mutated-deficient lung cancer cells.

Br J Cancer 2019 10 4;121(7):600-610. Epub 2019 Sep 4.

Departments of Biochemistry and Molecular Biology, Robson DNA Science Centre and Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, T2N 1N4, Canada.

Background: Up to 40% of lung adenocarcinoma have been reported to lack ataxia-telangiectasia mutated (ATM) protein expression. We asked whether ATM-deficient lung cancer cell lines are sensitive to poly-ADP ribose polymerase (PARP) inhibitors and determined the mechanism of action of olaparib in ATM-deficient A549 cells.

Methods: We analysed drug sensitivity data for olaparib and talazoparib in lung adenocarcinoma cell lines from the Genomics of Drug Sensitivity in Cancer (GDSC) project. We deleted ATM from A549 lung adenocarcinoma cells using CRISPR/Cas9 and determined the effects of olaparib and the ATM/Rad3-related (ATR) inhibitor VE-821 on cell viability.

Results: IC values for both olaparib and talazoparib positively correlated with ATM mRNA levels and gene amplification status in lung adenocarcinoma cell lines. ATM mutation was associated with a significant decrease in the IC for olaparib while a similar trend was observed for talazoparib. A549 cells with deletion of ATM were sensitive to ionising radiation and olaparib. Olaparib induced phosphorylation of DNA damage markers and reversible G2 arrest in ATM-deficient cells, while the combination of olaparib and VE-821 induced cell death.

Conclusions: Patients with tumours characterised by ATM-deficiency may benefit from treatment with a PARP inhibitor in combination with an ATR inhibitor.
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http://dx.doi.org/10.1038/s41416-019-0565-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6889280PMC
October 2019