Baseline and early functional immune response is associated with subsequent clinical outcomes of PD-1 inhibition therapy in metastatic melanoma patients.

BACKGROUND: Despite significant progress with antiprogrammed cell death protein 1 (PD-1) therapy, a substantial fraction of metastatic melanoma patients show upfront therapy resistance. Biomarkers for outcome are missing and the association of baseline immune function and clinical outcome remains to be determined. We assessed the in vitro nonspecific stimulation of immune response at baseline and during anti-PD-1 therapy for metastatic melanoma. METHODS: Previously untreated metastatic melanoma patients received nivolumab and radiotherapy as part of the multicentric phase II trial NIRVANA (NCT02799901). The levels of Th1, Th2 and Th17 cytokines on in vitro non-specific stimulation of innate and adaptive immune cells were measured in patient sera before treatment, and at week 2 and week 6 after the beginning of the treatment, and correlated with tumorous response, progression-free survival (PFS) and occurrence of immune-related adverse events (irAEs). The results in melanoma patients were compared with those of a cohort of 9 sex and age-matched healthy donors. RESULTS: Seventeen patients were enrolled in this ancillary study. Median follow-up was 16 months (2.2-28.4). The 12-month PFS rate was 67.7%. The incidence of irAEs of any grade was 58.8%. Without in vitro stimulation no differences in cytokines levels were observed between responders and non-responders. On in vitro stimulation, metastatic patients had lower Th1 cytokine levels than healthy donors at baseline for tumor necrosis factor-α and interferon-γ (IFN-γ) (1136 pg/mL vs 5558 pg/mL, p<0.0001; and 3894 pg/mL vs 17 129 pg/mL, p=0.02, respectively). Responders exhibited increasing cytokine levels from baseline to week 6. Non-responders had lower interleukin 17A (IL-17A) levels at baseline than responders (7 pg/mL vs 32 pg/mL, p=0.03), and lower IFN-γ levels at week 6 (3.3 ng/mL vs 14.5 ng/mL, p=0.03). A lower level of IL-17A at week 2 and a lower level of IFN-γ at week 6 correlated with worse PFS (p=0.04 and p=0.04 respectively). At baseline, patients who developed irAEs had higher IL-6 levels (19.3 ng/mL vs 9.2 ng/mL, p=0.03) and higher IL-17A levels (52.5 pg/mL vs 2.5 pg/mL, p=0.009) than those without irAEs. CONCLUSIONS: Our findings indicate that cytokine levels after in vitro non-specific stimulation could be a promising biomarker to predict the outcome of PD-1 inhibition therapy.

Germline variants in exonic regions have limited impact on immune checkpoint blockade clinical outcomes in advanced melanoma.

Immune checkpoint inhibition (ICI) treatments improve outcomes for metastatic melanoma; however, up to 60% of treated patients do not respond to ICI and/or develop immune-related adverse events (irAEs). Currently, robust and reliable biomarker to predict response and/or occurrence of irAEs to ICI are missing. Herein, we wanted to explore whether germline variants (SNPs) could predict the clinical outcomes of melanoma patients treated with ICIs. We performed a whole exome sequencing using gDNA isolated from blood, from a discovery cohort of 57 patients with metastatic melanoma. The top associations were then tested in a validation cohort of 57 patients. Our work suggests that individual germline genetic variants have no or weak impact on the response to ICIs. Only, variants in IL1RL1 have a significant impact in treatment response. The role of IL1RL1 in the immune response against melanoma and as a theranostic marker warrants further investigations.

Diabetes and Blood Glucose Disorders Under Anti-PD1.

Acute type 1 diabetes (AD1) is a rare but definitive immune-related adverse event associated with anti-PD1. Most of the reported cases are close to what has been described as "fulminant type 1 diabetes." We sought to determine whether anti-PD1 could impair glycoregulation and whether occurrence of AD1 could be anticipated by prior glycemic changes. Fasting glycemia collected before, under, and after treatment in melanoma patients treated with anti-PD1 over a period of 36 months were retrospectively analyzed. Glycemic trend analyses were performed using linear regression analysis. In total, 1470 glucose values were monitored in 163 patients treated for a mean duration of 5.96 months. Three patients developed an AD1 (1, 84%). Two other cases were observed in the same period in a still-blinded trial of anti-PD1 versus ipilimumab. All cases of AD1 occurred in patients with a normal pretreatment glycemia, and there was no detectable drift of glycemia before ketoacidosis onset. In 4 of 5 cases of AD1, the HLA subgroups were DRB01* 03 or 04, known to increase type 1 diabetes risk in the general population. In the 28 patients with preexisting type 2 diabetes, there was a slight trend for glycemia increase with anti-PD1 infusions (0.05 mmol/L/infusion P=0.004). In the 132 patients with normal pretreatment glycemia, there was a slight trend for a decrease of glycemia with anti-PD1 infusions (-0.012/mmol/L/infusion P=0.026). These data suggest that the monitoring of glycemia under anti-PD1 cannot help to anticipate AD1, and there is no general tendency to glycemic disorder. HLA genotyping before treatment may help to focus surveillance in patients with the HLA DRB1*03/04 group.