Clinical validation of a prognostic 11-gene expression profiling score in prospectively collected FFPE tissue of patients with AJCC v8 stage II cutaneous melanoma

BACKGROUND

Adjuvant therapies have been approved for patients with AJCC (American Joint Committee on Cancer) stage III and stage IV cutaneous melanoma (CM) after complete resection. These therapies might also be indicated for patients with high-risk stage II CM.

MATERIAL AND METHODS

We included patients diagnosed with stage II melanoma between 2000 and 2016 and for which primary tumour tissue was available. The prognostic value of the 11-gene expression profiling score (GEPS) was evaluated as a dichotomized parameter (GEPS ≤0 vs. >0). Endpoints of the analysis were melanoma specific survival (MSS), distant metastasis-free survival (DMFS) and relapse-free survival (RFS).

RESULTS

GEPS was determined in 245 patients ranging between -0.7 and 3.53. A total of 111 females and 134 males were included; the median follow-up was 41 months. Kaplan Meier analyses showed statistically significant survival differences between patients with high GEPS (n = 154) and low GEPS (n = 91) for MSS (p = 0.018), DMFS (p = 0.005) and RFS (p = 0.009). The 5-year and 10-year MSS was 92% in the low-GEPS and 82% and 67% in the high-GEPS group, respectively. Multivariate Cox regression analysis showed independent significance for MSS of GEPS (HR = 1.55; p = 0.006), tumor thickness (HR = 1.21; p < 0.001) and age (HR1.05; p = 0.002).

CONCLUSION

GEPS was validated as independent prognostic factor for MSS in stage II CM and could be used for therapeutic decisions when systemic therapies become available in stage II CM.

Randomized Phase II Trial and Tumor Mutational Spectrum Analysis from Cabozantinib versus Chemotherapy in Metastatic Uveal Melanoma (Alliance A091201)

PURPOSE

The surface receptor MET is highly expressed on primary uveal melanoma; MET inhibitors demonstrated early clinical signals of efficacy in slowing uveal melanoma growth. The primary objective of our study was to compare the progression-free survival rate at 4 months (PFS4) of patients with uveal melanoma treated with cabozantinib or chemotherapy.

PATIENTS AND METHODS

Patients with metastatic uveal melanoma and RECIST measurable disease were randomized 2:1 to receive either cabozantinib (arm 1) versus temozolomide or dacarbazine (arm 2) with restaging imaging every two cycles. Cross-over from arm 2 to cabozantinib after progression was allowed (arm 2X). Available tumor specimens were analyzed by whole-exome sequencing (WES) and results were correlated with outcome.

RESULTS

Forty-six eligible patients were accrued with 31, 15, and 9 in arms 1, 2, and 2X, respectively. Median lines of prior therapy, including hepatic embolization, were two. Rates of PFS4 in arm 1 and arm 2 were 32.3% and 26.7% (P = 0.35), respectively, with median PFS time of 60 and 59 days (P = 0.964; HR = 0.99). Median overall survival (OS) was 6.4 months and 7.3 months (P = 0.580; HR = 1.21), respectively. Grade 3-4 Common Terminology Criteria for Adverse Events were present in 61.3%, 46.7%, and 37.5% in arms 1, 2, and 2X, respectively. WES demonstrated a mean tumor mutational burden of 1.53 mutations/Mb and did not separate OS ≤ or >1 year (P = 0.14). Known mutations were identified by WES and novel mutations were nominated.

CONCLUSIONS

MET/VEGFR blockade with cabozantinib demonstrated no improvement in PFS but an increase in toxicity relative to temozolomide/dacarbazine in metastatic uveal melanoma.