Famous Brands, the South African owner of the group, said in a recent update that like for like sales rose 4% in the 16 weeks to 24 February 2019.
It comes after GBK closed 17 restaurants under the CVA at the end of last year. A further seven sites shut earlier in 2018.
Famous Brands said overall like for like sales at GBK in the first half of the year were -9.7%, but picked up to +1.6% in the second half of the year following the closure of several underperforming sites.
It said management was “optimistic" that "remedial actions" to save the brand were "starting to gain momentum”.
The CVA is expected to cost the company £18.3m, including redundancy payments, professional fees, compensation fund costs and store strip-out charges totalling £3.9m.
Famous Brands bought GBK for £120m in 2016 and opened a number of sites outside of its London heartland, which the company later admitted in its CVA proposal had struggled with “poor brand recognition in the north...and pricing and menus that were London-centric”.
GBK was founded in Battersea, London in 2001 by three New Zealanders with the backing of chef Peter Gordon.
It was bought by investment firm Yellowwoods Group in 2010, leading to rapid growth of the chain.