Antibiotics May Compromise Immunotherapy Efficacy in Kidney Cancer

Patients with metastatic kidney cancer may see a decreased efficacy of their immunotherapy regimen if they recently took antibiotics.
LISA MILLER
PUBLISHED: FEBRUARY 14, 2017
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Immunotherapy efficacy may be compromised if the patient takes antibiotics up to a month before treatment, according to the results of a retrospective analysis presented during a presscast of the 2017 Genitourinary Cancers Symposium, which raised concern about the relationship between gut microbacteria and antibiotics and their effect on immune checkpoint blockade agents.

In patients with metastatic renal cell carcinoma (mRCC), patients who had received broad-spectrum antibiotics had a shorter median progression-free survival (PFS) rate when treated with checkpoint inhibitor immunotherapy than those who had not received antibiotics of 2.3 versus 8.1 months, respectively.

Previous preclinical studies using mouse models have suggested an association between antibiotics and the efficacy of immune checkpoint blockade agents. 
 
“This is the first analysis evaluating the impact of antibiotics on outcome in mRCC patients treated in the era of immune checkpoint blockade,” said investigator Lisa Derosa, M.D., Ph.D. candidate, of the Gustave Roussy Cancer Institute, Paris-Sud University in Villejuif, France.

Researchers analyzed 80 patients with mRCC who were being treated with checkpoint inhibitors on trials at the Gustave Roussy institute. Immunotherapy treatments included single-agent anti–PD-1/PD-L1 therapy (67 patients), a combination of a PD-1 inhibitor and a CTLA-4 inhibitor (10 patients), and a combination of anti–PD-L1 therapy and Avastin (bevacizumab; three patients).

A majority of the enrolled patients were male (65 percent), 88 percent had a clear-cell histology, and 80 percent of the patients had prior nephrectomy. Twenty-one percent had favorable disease by International mRCC Database Consortium (IMDC) risk standards, 57 percent had intermediate IMDC risk, and 22 percent had poor-risk disease. Sixteen patients (20 percent) had received antibiotics up to one month prior to starting treatment with immunotherapy, including mostly beta-lactamases or fluoroquinolones.

At a median follow-up of six months, overall survival (OS) results were not yet able to be reached in the overall population, but a negative trend was already noted for patients who received prior antibiotics. The objective response rate also favored patients who had not received antibiotics.

In a subgroup of 62 patients who were treated with Opdivo (nivolumab) monotherapy, patients who had not taken antibiotics showed a greater PFS rate, which also achieved statistical significance. OS in the Opdivo monotherapy subgroup was also significantly higher in patients who had not taken recent antibiotics.



Talk about this article with other patients, caregivers, and advocates in the Kidney Cancer CURE discussion group.
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