Conference Coverage

Lymphopenia linked to worse response in RCC, bladder cancer patients on checkpoint inhibitors


 

REPORTING FROM THE CLINICAL IMMUNO-ONCOLOGY SYMPOSIUM

Response to checkpoint inhibitors was associated with pretreatment absolute lymphocyte count (pALC) and neutrophil-lymphocyte ratio (pNLR) in patients with kidney or bladder cancer treated in a real-world setting.

Tonjeh M. Bah, MD, a clinical research fellow at LSU-Feist-Weiller Cancer Center, Shreveport, La. Sharon Worcester/MDedge News

Dr. Tonjeh M. Bah

In a retrospective study of 20 patients, those with lower pALCs and higher pNLRs were less likely to respond to checkpoint inhibitors.

Tonjeh Bah, MD, of Feist-Weiller Cancer Center at LSU Health Shreveport in Louisiana, and colleagues reported these results in a poster at the ASCO-SITC Clinical Immuno-Oncology Symposium.

Response rates were 75% in patients with pALC greater than 1,000 and 25% in patients with pALC less than 1,000. This difference was statistically significant (P = .027), Dr. Bah noted, adding that the groups were comparable with respect to age, sex, race, and type of checkpoint inhibitors used.

Similarly, response rates were 80% in patients with pNLR less than 3 (the established upper limit of normal) and 30% in patients with pNLR greater than 3 (P = .024).

Checkpoint inhibitors targeting cytotoxic T-lymphocyte-associated protein 4 and programmed death-1 and its ligand are essential components of therapy across multiple cancer types, Dr. Bah noted in an interview. She explained that prior studies – mostly in patients with lung cancer and head and neck cancers – have also shown pALC and pNLR to be independently associated with poor checkpoint inhibitor response and worse progression-free survival.

“But this is the first study to look at the connection in kidney and bladder cancer in a real-world setting,” she said.

Dr. Bah and colleagues conducted the study to test the hypothesis that “lymphopenia is a marker of immune exhaustion, which is characterized by dysfunctional T cells that have a limited antitumor effect even in the presence of [checkpoint inhibitors] and by the eventual depletion of antitumor lymphocytes,” they wrote in the poster.

Patients included in the study were all those with renal cell carcinoma (n = 13) or bladder-urothelial cancers (n = 7) who received checkpoint inhibitors at one of two medical centers in Louisiana during 2015-2019 and who had outcomes reported. Patients who attained stable disease or had partial or complete responses were categorized as responders. Patients who progressed on checkpoint inhibitors were considered nonresponders.

“Our findings were not a surprise, but they do document, for the first time and in a real-world setting, that pALC and pNLR may have prognostic utility in patients with kidney and bladder cancers who are treated with [checkpoint inhibitors],” Dr. Bah said.

She added that the findings could help determine which patients are candidates for checkpoint inhibitors, but the results require confirmation in a large, prospective study. Dr. Bah reported having no disclosures, and there was no sponsor for this study.

SOURCE: Bah T et al. ASCO-SITC 2020. Abstract 31.

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