Frontline nelitolimod plus pembrolizumab combo elicits response in advanced melanoma

The toll-like receptor 9 agonist nelitolimod, when combined with pembrolizumab, shows promising antitumour activity in treatment-naïve patients with anti–PD-1/PD-L1 advanced melanoma, according to a phase II open-label trial.

The study included 86 patients with advanced melanoma who were naïve to anti–PD-1/PD-L1 therapy. These patients received nelitolimod either at 2 mg injected into 1 to 4 lesions (n=45) or at 8 mg injected weekly into a single lesion (n=41) for 4 weekly doses and then every 3 weeks. All patients received pembrolizumab at 200 mg, administered intravenously every 3 weeks.

The main outcome was objective response rate (ORR). Progression-free survival (PFS) and safety were also evaluated.

ORR was 76 percent in the 2-mg arm and 49 percent in the 8-mg arm. ORRs were similar in the subgroup of patients with distant metastases.

In the 2-mg arm specifically, ORRs did not significantly differ between patients with PD-L1–positive tumours and those with PD-L1–negative tumours.

PFS rate at 18 months was 62 percent in the 2-mg arm and 40 percent in the 8-mg arm.

In terms of safety, treatment-related adverse events with either nelitolimod or pembrolizumab were reported in all patients in the 2-mg arm and in 95 percent of those in the 8-mg arm. Overall, 37 percent of patients had a grade 3 or 4 treatment-related adverse event related to either study drug.