LONDON: GlaxoSmithKline has won a further reprieve for its blockbuster Advair lung drug after US regulators insisted Hikma Pharmaceuticals conduct a further clinical study evaluating its generic version of the drug. The Jordan-based firm said on Monday it expected to submit a response to the US Food and Drug Administration (FDA) with new clinical data in 2019. Hikma’s partner on the project, Vectura, said this meant a potential approval and launch of the generic inhaled medication could come in 2020 if all goes well. Shares in Hikma fell 1 percent in early trade, while Vectura lost 5 percent. Hikma already faced a delay in US approval for its Advair generic in 2017, as did rival generics company Mylan, and last month a third Advair copy from Novartis’s Sandoz division also got knocked back by the FDA. Hikma had disputed the FDA’s demand that it to conduct a fresh clinical endpoint study, but the agency upheld its original determination. After Hikma and Mylan’s problems in 2017, most industry analysts expected the generic threat had been pushed back until mid-2018. The latest snags mean GSK may enjoy more Advair profits for longer, although Mylan still has a chance to win a US green light for its version of generic Advair in 2018. The timing of the arrival of generic Advair in the United States is critical to GSK’s near-term earnings outlook. The drugmaker expects its 2018 earnings, at constant exchange rates, to be flat to down 3 percent if generic Advair launches in the US market by mid-year. Without generics, earnings would be up 4 to 7 percent.