Shares of Iovance Biotherapeutics rose after the company boosted its full-year revenue forecast, citing strong demand for two melanoma treatments.

The stock gained 20% to $13.17 in premarket trading on Tuesday. At Monday's market close, shares had more than quadrupled year to date.

Iovance now projects revenue of $410 to $420 million this year, up from a previous range of $350 to $370 million.

The company said it updated its outlook due to strong U.S. demand for amtagvi and proleukin, two treatments for advanced melanoma.

"Increasing patient demand and our current manufacturing schedule provide strong visibility into our third and fourth quarter revenues," said Frederick Vogt, interim president and chief executive.