COMBI-r: A Prospective, Non-Interventional Study of Dabrafenib Plus Trametinib in Unselected Patients with Unresectable or Metastatic BRAF V600-Mutant Melanoma

SIMPLE SUMMARY: The outcome of patients with advanced melanoma has profoundly improved over the last 15 years. Novel medications blocking BRAF, a protein involved in stimulating cell division, or inhibiting immune checkpoints associated with T-cell activation significantly improved overall survival. Mutations of the BRAF protein kinase cause cells to make an abnormal protein that promotes tumor growth. In patients with BRAF V600 mutations, dabrafenib and trametinib blocking BRAF V600 and MEK, respectively, have demonstrated improved efficacy in two large clinical trials (COMBI-d, COMBI-v) compared to blocking BRAF signaling with single agents. This led to the approval of dabrafenib plus trametinib for the treatment of patients with advanced melanoma. The study (COMBI-r) presented here investigated the use of dabrafenib plus trametinib in everyday clinical practice. COMBI-r confirms the data from COMBI-d and COMBI-v and provides additional data in patients with brain metastases or previous treatments who had been excluded from the pivotal trials. ABSTRACT: Combined BRAF/MEK-inhibition constitutes a relevant treatment option for BRAF-mutated advanced melanoma. The prospective, non-interventional COMBI-r study assessed the effectiveness and tolerability of the BRAF-inhibitor dabrafenib combined with the MEK-inhibitor trametinib in patients with advanced melanoma under routine clinical conditions. Progression-free survival (PFS) was the primary objective, and secondary objectives included overall survival (OS), disease control rate, duration of therapy, and the frequency and severity of adverse events. This study enrolled 472 patients at 55 German sites. The median PFS was 8.3 months (95%CI 7.1–9.3) and the median OS was 18.3 months (14.9–21.3), both tending to be longer in pre-treated patients. In the 147 patients with CNS metastases, PFS was similar in those requiring corticosteroids (probably representing symptomatic patients, 5.6 months (3.9–7.2)) compared with those not requiring corticosteroids (5.9 months (4.8–6.9)); however, OS was shorter in patients with brain metastases who received corticosteroids (7.8 (6.3–11.6)) compared to those who did not (11.9 months (9.6–19.5)). The integrated subjective assessment of tumor growth dynamics proved helpful to predict outcome: investigators’ upfront categorization correlated well with time-to-event outcomes. Taken together, COMBI-r mirrored PFS outcomes from other prospective, observational studies and confirmed efficacy and safety findings from the pivotal phase III COMBI-d/-v and COMBI-mb trials.