Effect of antimicrobial therapy on progression-free survival of immunotherapy and chemo-/immunotherapy in patients with non-small cell lung cancer.

BACKGROUND

The choice between immunotherapy with a checkpoint inhibitor (CPI) and chemo-/immunotherapy (CIT) in patients with NSCLC stage IV is often discussed. There are some data that the effect of CPI therapy is impaired by antimicrobial therapy (AMT). Little is known about the influence of AMT on CIT.

PATIENTS AND METHODS

We retrospectively analysed 114 patients (age 68 ± 8.5 years) with NSCLC stage IV. Patients were treated according to the guidelines with either CPI alone (pembrolizumab, nivolumab, atezolizumab, cemiplimab) or CIT (Carboplatin/Pemetrexed/Pembrolizumab, Carboplatin/Paclitaxel/Pembrolizumab). We registered patients' characteristics including presence and timing of AMT. Group 1 consisted of 42 patients with AMT in the month before CPI or CIT, group 2 were 49 patients with AMT during CPI or CIT, and group 3 were 64 patients without AMT and CPI or CIT.

RESULTS

Group 1-3 showed comparable patients characteristics. Using cox-regression analysis, we found that AMT in the month before CPI resulted in a decreased progression-free survival (PFS) compared to patients with CPI and no AMT (14 ± 1.02 vs. 4 ± 1.02 months, p = 0.002, 95% CI 1.88-9). In patients, who were treated with CIT, there was no difference in PFS in those with or without AMT in the month before therapy (10 ± 2.5 vs. 6 ± 1.2 months, p = 0.7). Interestingly, AMT during CIT or CPI therapy showed no effect on PFS.

CONCLUSIONS

In a real-life setting, we found that AMT reduces PFS when given in the month before CIT therapy. AMT before or during CIT does not seem to influence PFS. As a consequence, AMT before start of therapy might be a factor that could lead to a preference of CIT instead of CPI in NSCLC stage IV patients.