Mehmet Altan

Dr. Mehmet Altan

orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

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

Representative Publications

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2 April 2019 in Journal for ImmunoTherapy of Cancer
Verified
Journal Article
Open access
PDF file
HAHamzah Abu-Sbeih
Hamzah Abu-Sbeih
FAFasial S Ali
Fasial S Ali
XWXuemei Wang
Xuemei Wang
NMNiharika Mallepally
Niharika Mallepally
ECEllie Chen
Ellie Chen
Yinghong WangYinghong Wang
Yinghong Wang
Background Current treatment guidelines for immune-mediated colitis (IMC) recommend 4 to 6 weeks of steroids as first-line therapy, followed by selective immunosuppressive therapy (SIT) (infliximab or vedolizumab) in patients who do not respond to steroids. We assessed the effect of early SIT introduction and number of SIT infusions on clinical outcomes. Methods We performed a retrospective review of patients with IMC who received SIT at The University of Texas MD Anderson Cancer Center between January and December 2018. Logistic regression analyses were used to assess associations between clinical outcomes and features of IMC. Results Of the 1459 patients who received immune checkpoint inhibitors, 179 developed IMC of any grade; 84 of these 179 patients received SIT. Of the 84 patients who received SIT, 79% were males, and the mean age was 60 years (standard deviation, 14). Compared with patients who received SIT > 10 days after IMC onset, patients who received early SIT (≤10 days) required fewer hospitalizations (P = 0.03), experienced steroid taper failure less frequently (P = 0.03), had fewer steroid tapering attempts (P < 0.01), had a shorter course of steroid treatment (P = 0.09), and had a shorter duration of symptoms (P < 0.01). Patients who received one or two infusions of SIT achieved histologic remission less frequently (P = 0.09) and had higher fecal calprotectin levels after SIT (P = 0.01) compared with patients who received three or more infusions. Risk factors for IMC recurrence after weaning off steroids included: 1) needing multiple hospitalizations, 2) experiencing steroid taper failure after SIT, 3) receiving infliximab rather than vedolizumab, 4) receiving fewer than three infusions of SIT, 5) having higher fecal calprotectin levels after SIT, and 6) receiving a longer course of steroids, hospitalization and IMC symptoms. Unsuccessful weaning from steroids after SIT was associated with high IMC grades; multiple hospitalizations; steroid-resistant IMC; long interval from IMC to SIT initiation; and long duration of steroids, IMC symptoms, and hospitalization. Conclusion SIT should be introduced early in the disease course of IMC instead of waiting until failure of steroid therapy or steroid taper. Patients who received three or more infusions of SIT had more favorable clinical outcomes.

6 February 2019 in Journal for ImmunoTherapy of Cancer
Verified
Journal Article
Open access
PDF file
HAHamzah Abu-Sbeih
Hamzah Abu-Sbeih
TTTenglong Tang
Tenglong Tang
YLYang Lu
Yang Lu
STSelvi Thirumurthi
Selvi Thirumurthi
MAMehmet Altan
Mehmet Altan
Yinghong WangYinghong Wang
Yinghong Wang
Background Immune checkpoint inhibitor (ICI)-induced pancreatic injury (ICIPI) is not well documented in the literature. We aimed to describe the clinical characteristics and outcomes of patients who developed ICIPI. Methods We reviewed the medical records of consecutive patients who had a confirmed diagnosis of ICIPI (Common Terminology Criteria for Adverse Events grade ≥ 3 lipase elevation with or without clinical symptoms) from April 2011 through April 2018. Results Among the 2,279 patients received ICI and had lipase values checked thereafter, 82 (4%) developed ICIPI. Overall, 65% of patients received inhibitors of programmed death protein-1 or its ligand. Compared with asymptomatic presentation, patients who had clinical symptoms of pancreatitis (n = 32) had higher levels of lipase (P = 0.032), more frequent imaging evidence of pancreatitis (P = 0.055), and more frequent hospitalization (P < 0.001) and received intravenous fluids (P < 0.001) and steroids more frequently (P = 0.008). Twelve patients (15%) developed long-term adverse outcomes of ICIPI; three had chronic pancreatitis, four had recurrence of ICIPI, and six had subsequent diabetes. Among 35 patients who resumed ICI therapy, four (11%) had recurrence of lipase elevation. Logistic regression revealed that smoking and hyperlipidemia were associated with increased risk for long-term adverse outcomes of ICIPI, and intravenous fluids were associated with reduced risk. Patients who resumed ICI therapy survived longer than patients who discontinued ICI therapy permanently, statistically not significant (P = 0.0559). Patients who developed long-term adverse outcomes of ICIPI survived significantly longer than those who did not (P = 0.0295). The highest proportion of patients (6/21, 29%) developed long-term adverse outcomes of ICIPI was among those without typical symptoms of pancreatitis, continued ICI therapy after ICIPI, and did not receive intravenous fluids. Conclusion ICIPI can present as typical acute pancreatitis, with risk of the development of a pseudocyst, diabetes, and chronic pancreatitis. ICI resumption after ICIPI may lead to recurrence of lipase elevation without increased risk of long-term adverse outcomes, and can increase survival duration. Intravenous fluids may prevent long-term adverse outcomes, but steroids do not appear to affect outcomes of ICIPI. Asymptomatic ICIPI presentation may lead to undertreatment of ICIPI owing to underestimation of its degree, and therefore, intravenous fluid administration could potentially could potentially be benificial to prevent long-term adverse outcomes even in asymptomatic patients.

11 April 2024 in Nature Communications
Verified
Journal Article
Open access
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SSSheeba Jenifer Sujit
Sheeba Jenifer Sujit
MAMuhammad Aminu
Muhammad Aminu
TKTatiana V. Karpinets
Tatiana V. Karpinets
Pingjun ChenPingjun Chen
Pingjun Chen
MSMaliazurina B. Saad
Maliazurina B. Saad
Jia WuJia Wu
Jia Wu
While we recognize the prognostic importance of clinicopathological measures and circulating tumor DNA (ctDNA), the independent contribution of quantitative image markers to prognosis in non-small cell lung cancer (NSCLC) remains underexplored. In our multi-institutional study of 394 NSCLC patients, we utilize pre-treatment computed tomography (CT) and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) to establish a habitat imaging framework for assessing regional heterogeneity within individual tumors. This framework identifies three PET/CT subtypes, which maintain prognostic value after adjusting for clinicopathologic risk factors including tumor volume. Additionally, these subtypes complement ctDNA in predicting disease recurrence. Radiogenomics analysis unveil the molecular underpinnings of these imaging subtypes, highlighting downregulation in interferon alpha and gamma pathways in the high-risk subtype. In summary, our study demonstrates that these habitat imaging subtypes effectively stratify NSCLC patients based on their risk levels for disease recurrence after initial curative surgery or radiotherapy, providing valuable insights for personalized treatment approaches.

1 June 2019 in Journal of Thoracic Oncology
Verified
Journal Article
Closed access
MAMehmet Altan
Mehmet Altan
MTMaria I. Toki
Maria I. Toki
SGScott N. Gettinger
Scott N. Gettinger
DCDaniel E. Carvajal-Hausdorf
Daniel E. Carvajal-Hausdorf
JZJon Zugazagoitia
Jon Zugazagoitia
DRDavid L. Rimm
David L. Rimm

5 September 2019 in Journal for ImmunoTherapy of Cancer
Verified
Journal Article
Open access
PDF file
HAHamzah Abu-Sbeih
Hamzah Abu-Sbeih
LHLauren Nicholas Herrera
Lauren Nicholas Herrera
TTTenglong Tang
Tenglong Tang
MAMehmet Altan
Mehmet Altan
ACAnne-Marie P. Chaftari
Anne-Marie P. Chaftari
Yinghong WangYinghong Wang
Yinghong Wang
Background The gut microbiome impacts the efficacy of immune checkpoint inhibitor (ICI) therapy and the development of ICI-mediated diarrhea and/or colitis (IMDC). Antibiotic therapy,especially that with anaerobic activity, has profound effects on the gut microbiome. Therefore, we sought to assess the effect of antibiotics on the development of IMDC. Methods Patients who received ICI therapy from January 2016 to January 2018 were examined retrospectively. A Cox regression model was used to assess factors associated with overall survival. Results A total of 826 patients were included. Of these patients, 51.6% received inhibitors of programmed cell death protein-1 or its ligand, 32.0% received inhibitors of cytotoxic T-lymphocyte-associated antigen-4, and 16.5% received a combination of the two. IMDC occurred in 52.5% of the patients after a median of 8 weeks. Overall, 569 patients (68.9%) received antibiotic therapy. Antibiotic use at any time was associated with reduced IMDC occurrence and recurrence rates but also with frequent hospitalization and intensive care unit admission for IMDC as well as increased IMDC severity. Compared with patients who received antibiotic therapy only before ICI therapy initiation, those receiving it after ICI had a higher IMDC rate and more often needed immunosuppressive therapy and hospitalization for IMDC. Antibiotics with anaerobic activity were included in 51% of the antibiotic therapy regimens and were associated with increased immunosuppressant use, hospitalization, intensive care unit admission for IMDC, and severe IMDC grades. Forty-one patients received empiric prophylactic antibiotic therapy at IMDC onset. These patients more often needed immunosuppressive therapy, intravenous steroids, and infliximab/vedolizumab; had more frequent and longer hospitalization for IMDC and higher IMDC grades; and more frequently had IMDC recurrence than did patients who did not receive antibiotic therapy at the time of IMDC symptom onset. Conclusions Whereas antibiotic therapy appeared to be protective against IMDC onset, use of antibiotics, especially those with anaerobic activity, after ICI therapy was associated with increased risk of severe IMDC.

16 March 2023 in Journal for ImmunoTherapy of Cancer
Verified
Journal Article
Open access
PDF file
SPSophie Postel-Vinay
Sophie Postel-Vinay
VLVincent K Lam
Vincent K Lam
WRWilleke Ros
Willeke Ros
TBTodd M Bauer
Todd M Bauer
AHAaron R Hansen
Aaron R Hansen
JHJohn V Heymach
John V Heymach
Background The phase I first-in-human study ENGAGE-1 evaluated the humanized IgG1 OX40 agonistic monoclonal antibody GSK3174998 alone (Part 1 (P1)) or in combination with pembrolizumab (Part 2 (P2)) in patients with advanced solid tumors. Methods GSK3174998 (0.003–10 mg/kg) ± pembrolizumab (200 mg) was administered intravenously every 3 weeks using a continuous reassessment method for dose escalation. Primary objectives were safety and tolerability; secondary objectives included pharmacokinetics, immunogenicity, pharmacodynamics, and clinical activity. Results 138 patients were enrolled (45 (P1) and 96 (P2, including 3 crossovers)). Treatment-related adverse events occurred in 51% (P1) and 64% (P2) of patients, fatigue being the most common (11% and 24%, respectively). No dose-toxicity relationship was observed, and maximum-tolerated dose was not reached. Dose-limiting toxicities (P2) included Grade 3 (G3) pleural effusion and G1 myocarditis with G3 increased troponin. GSK3174998 ≥0.3 mg/kg demonstrated pharmacokinetic linearity and >80% receptor occupancy on circulating T cells; 0.3 mg/kg was selected for further evaluation. Limited clinical activity was observed for GSK3174998 (P1: disease control rate (DCR) ≥24 weeks 9%) and was not greater than that expected for pembrolizumab alone (P2: overall response rate 8%, DCR ≥24 weeks 28%). Multiplexed immunofluorescence data from paired biopsies suggested that increased infiltration of natural killer (NK)/natural killer T (NKT) cells and decreased regulatory T cells (Tregs) in the tumor microenvironment may contribute to clinical responses: CD16+CD56–CD134+ NK /NKT cells and CD3+CD4+FOXP3+CD134+ Tregs exhibited the largest magnitude of change on treatment, whereas CD3+CD8+granzyme B+PD-1+CD134+ cytotoxic T cells were the least variable. Tumor gene expression profiling revealed an upregulation of inflammatory responses, T-cell proliferation, and NK cell function on treatment with some inflammatory cytokines upregulated in peripheral blood. However, target engagement, evidenced by pharmacologic activity in peripheral blood and tumor tissue, did not correlate with clinical efficacy. The low number of responses precluded identifying a robust biomarker signature predictive of response. Conclusions GSK3174998±pembrolizumab was well tolerated over the dose range tested and demonstrated target engagement. Limited clinical activity does not support further development of GSK3174998±pembrolizumab in advanced cancers. Trial registration number NCT02528357.