Efficacy of immunotherapy (Prolgolimab) and targeted therapy (Trametinib and Dabrafenib, Cobimetinib and Vemurafenib) in adult patients with metastatic or unresectable skin melanoma: matching-adjusted indirect comparison

Abstract

Aim. To assess the comparative clinical efficacy of Prolgolimab monotherapy versus combination therapy with BRAF/MEK inhibitors (Dabrafenib and Trametinib, Vemurafenib and Cobimetinb) in adult patients with metastatic or unresectable skin melanoma implementing a matching-adjusted indirect comparison (MAIC).
 Materials and methods. We conducted a systematic search for randomized clinical trials of Prolgolimab, combinations of Dabrafenib and Trametinib, Cobimetinib and Vemurafenib. Unanchored MAIC was applied due to the absence of common comparator between trials. We determined effect modifiers based on an expert survey. The population from Prolgolimab studies was weighted using defined effect modifiers, followed by the approximation of survival curves.
 Results. Systematic literature search revealed 4 RCTs that met the inclusion criteria: MIRACULUM, coBRIM, combi-v and combi-d. To increase the power of prolgolimab comparison, data from the observational study FORA were included in evidence synthesis and combined with data from MIRACULUM. We selected M staging and the proportion of patients with elevated LDH levels as effect modifiers. No significant differences (all p0.05) were established between Prolgolimab and combination therapy with BRAF/MEK inhibitors for both OS after 1 year and PFS outcomes after 2 years from initiation.
 Discussion. Despite the inclusion of observational data and the limitations of adjusted indirect comparison method, the results of this analyses are consistent with both other comparisons of anti-PD1 inhibitors with BRAF/MEK inhibitors, and with real world data. It is necessary to recompare targeted therapy and immunotherapy after five-year follow-up period due to peculiarities of time of onset of their effect with the presence of a primary failure with a gradual exit to a long plateau on anti-PD1 inhibitors therapy.
 Conclusion. In these unanchored MAICs, Prolgolimab monotherapy showed comparable efficacy with combinations of BRAF/MEK inhibitors (Dabrafenib + Trametinib, Vemurafenib + Cobimetinib) in first line therapy of patients with metastatic or unresectable melanoma. This analysis may be relevant for clinical decision-making about the choice of the first line therapy for patients with BRAF mutation.