[Clinical Evaluation of the Efficacy and Adverse Effects of Nivolumab Treatment for Patients with Advanced Gastric Cancer].

BACKGROUND

Nivolumab, a fully human IgG4 monoclonal antibody inhibitor of programmed death-1(PD-1), was approved for use in the treatment of patients with advanced gastric or gastroesophageal junction cancer who had been previously treated with B2 chemotherapy regimens in Japan.

METHODS

We investigated the efficacy of nivolumab therapy in 15 consecutive patients with advanced gastric cancer between October 2017 and December 2018 in our facility.

RESULTS

In our study, the 6-month overall survival rate was 67.7%, and the median survival time(MST)was 6.3 months. Immune-related adverse events(irAEs)occurred in the following patients: 2 patients, interstitial pneumonia(13%); 1 patient, myocarditis (6.7%); 1 patient, hypothyroidism(6.7%); and 1 patient, liver dysfunction(6.7%). Of the patients with an absolute lym- phocyte count(ALC)of C2,000/mL at baseline, 33%(4/12)experienced irAEs, while of those with an ALC of >2,000/mL, 67% had irAEs. The 6-month overall survival rate was better in patients with an ALC >1,600/mL(100%, 4/4)than in those with an ALC of C1,600/mL(35%, 4/11). The 6-month overall survival rate of the patients with a neutrophil-to-lymphocyte ratio(NLR)of <4 was 63%, which was better than the 33% rate in those with an NLR of B4.

CONCLUSIONS

Nivolumab therapy was a safe and feasible treatment option. The cutoff values of ALC of 2,000/mL for irAEs and of ALC of 1,600/mL and NLR of 4 for prognosis might be effective surrogate markers in nivolumab treatment.