Generic drugmaker Hikma Pharmaceuticals and partner Vectura Group have announced plans for a clinical trial testing its version of GlaxoSmithKline’s asthma and chronic obstructive pulmonary syndrome drug, Advair Diskus.

The announcement follows a dispute resolution with the US Food and Drug Administration (FDA) after the agency requested further study to support the companies’ new drug application. After the dispute resolution process, the FDA upheld its original decision.

The administration called for major amendments to Hikma and Vectura’s drug application in May last year, though Hikma and Vectura’s press releases at the time said “no material issues were raised regarding the substitutability of the proposed device”.

Hikma said it had anticipated the FDA’s request for further study and has made preparations for patient recruitment for the new clinical trial to start in the next few weeks, with the hope that findings will be submitted to the FDA early in 2019. In a statement the company said it is still “committed to bringing this important product to the US market”, while Vectura said it remains “confident in the approvability of the product”.

“Whilst the outcome of the dispute resolution process is disappointing, we now have a clear pathway forwards, and we and our partner Hikma remain confident in, and committed to the approval of [generic drug candidate] VR315,” Vectura CEO James Ward-Lilley said.

“Assuming the successful execution of the new study and a standard regulatory review, we now expect a potential approval and launch during 2020.

“[We] have cleared up a significant number of issues which we believe has strengthened our insight and likelihood of success.”

Hikma’s generic asthma treatment is based on a fluticasone propionate and salmeterol inhalation powder delivered using Vectura’s proprietary dry powder inhaler and formulation technology. The treatment aims to minimise airflow obstruction and reduce exacerbations in patients with chronic obstructive pulmonary disease.

Another generic version of Advair is currently under development by Consort Medical and Mylan, with an FDA decision on their application expected by mid-2018.

Last month GlaxoSmithKline said that its adjusted earnings per share were anticipated to grow 4-7% if no generic competitor to Advair was launched by mid-2018, however if a competitor reached market by this time its shares were expected to fall by around 3%.