Analysts upped the price target to 1,900p from 1,610p with GSK tipped to regain lost ground having underperformed the EU large-cap group by around 25% year to date.
HIV sales are expected to grow by mid-single-digits in 2020 after a slow down this year.
An injectable drug that launches in the US this year also might generate revenues of almost £700mln by 2023.
According to the broker, the injectable formulation can relieve patients from the anxiety of having to take daily drugs, with demand pushing US front line market share into mid-single digits over the next three years.
GSK is also rebuilding the oncology division, but there are risks over approval of two key assets: an antibody for patients with bone marrow cancer, that could reach over £1bn annual sales, and a treatment for advanced cancers that could be “a significant source of upside”.
Another successful drug could be Shingrix, a shingles vaccine for people over 50, which has been suffering from capacity constraints as demand in the US has far outstripped supply.
There are plans to bring extra production capacity in 2024, with UBS assuming sales to peak at £4bn in 2027.
Shares were flat on Thursday morning to 1,703.15p.