Melker remained in GP3 with the Mücke team for the 2011 season, alongside Michael Christensen and Luciano Bacheta (who was later replaced by Daniel Mancinelli).

This gave him the early championship lead, and he took a further four podium finishes, but he ultimately slipped to third place behind the Lotus ART duo of Valtteri Bottas and James Calado after his team appeared to lose its competitive edge following mid-season testing at Barcelona.

[9] As well as his 2011 GP3 campaign, Melker competed in the season's Formula 3 Euro Series, also with Mücke, finishing in fourth position in the drivers' standings with four wins.

After participating in the non-championship 2011 GP2 Final with DAMS, Melker switched to Ocean Racing Technology for the 2012 season, initially alongside Jon Lancaster.

Melker made his racing début in a Formula Renault 3.5 car at Silverstone 2012, replacing César Ramos at the Lotus team.

After a disappointing season in GP2, Melker went to Formula Renault 3.5 full-time for 2013, driving for previous year's team champions Tech 1 Racing alongside series veteran Mikhail Aleshin.

He was competitive immediately, finishing second twice at the opening round in Portugal, before taking a double victory at Circuito de Navarra.