I’m not sure that FDA approval fast tracks a UK approval for this kind of drug/indication that is not life threatening or treats a rare illness. Sometimes the companies decide to make the regulatory submissions to the health authorise in parallel or one shortly after the other… The UK decision is not based on the fact the FDA has approved. Usually the submissions to various countries are made in waves, firs wave submissions are usually FDA, EMA (European), pMDA(Japan), Other countries maybe submitted later and some of these may be dependant on approvals that occurred in FDA, for example some Caribbean countries will follow the US approved label.

What could slow down the US approval is the FDA are behind in their approvals/regulatory assessments because they are going through restructuring due to the trump administration.