Katy Perry is to headline amfAR's annual Cinemas Against AIDS event.

The performance will be watched by a host of big-name celebrities, including Sharon Stone, amfAR's global campaign chair, as well as 'Superman Returns' actor Kevin Spacey and German model Heidi Klum.

The event is in its 23rd year and in 2015, raised more than $170 million for AIDS research.

In addition to Katy's much-anticipated performance, the fundraiser will also feature a fashion show curated by former editor-in-chief of Vogue Paris, Carine Rotifeld.

Meanwhile, Katy recently won a significant step in her battle to buy a Roman Catholic convent in Los Angeles.

The pop star is keen to buy the eight-acre property from the archdiocese of Los Angeles, run by Archbishop Jose Gomez.

However, the nuns living in the building considered the singer an unsuitable owner and instead wanted to sell to Dana Hollister, a businesswoman who wanted to use it as a hotel.

But earlier this month, Los Angeles superior court judge Stephanie Bowick approved the archdiocese's motion to block the sale to Hollister as she ruled the sale was improper.