Primary voters in three states reshaped several contests on Tuesday, with a Democratic Socialist winning a Florida state Senate nomination and Trump-backed Republicans posting mixed results.

Moderna's stock more than doubled after the company reported that an experimental cancer vaccine, developed with Merck, reduced the recurrence of melanoma when used alongside the immunotherapy drug Keytruda.

Sen. Jon Ossoff of Georgia named White House aide Natalie Harp in criticizing the Trump administration, prompting a response from the White House.

President Trump has signaled interest in reopening talks with North Korean leader Kim Jong Un and floated reducing joint military exercises with South Korea, but Pyongyang has rejected the overture. Commentators across the spectrum have offered competing readings of the moment.

The US Treasury said it will double the size of some of its debt buyback operations, raising the maximum for certain buybacks to at least $4 billion, in a move aimed at steadying the market for government bonds. Stocks, bonds and gold rose after the announcement.