What is the name of H&M's exclusive runway collection launched in 2015?

The name of H&M’s exclusive runway collection was H&M Studio. It is H&M’s more directional, limited-edition fashion offering, developed by an in-house design team and presented through seasonal shows.

H&M Studio’s autumn/winter 2015 collection was unveiled at Paris Fashion Week in the Grand Palais. Its sporty-futurist designs included functional outerwear, slim trousers, jumpsuits, lurex knitwear and sequined pieces. Models including Kendall Jenner, Gigi Hadid and Edie Campbell appeared in the show, which was watched by an international audience online.

A useful date clarification is that H&M Studio itself was launched in 2013; 2015 refers to the prominent runway collection and show described in the question. It is also distinct from H&M’s designer collaborations, such as Balmain x H&M, and from Conscious Exclusive, which focused more strongly on sustainability.