New Delhi, Aug. 19 -- Moderna co-founder Robert Langer has returned to billionaire status after the biotechnology company's shares rose 120%, on Wednesday (19 August) following encouraging late-stage trial results for its experimental melanoma vaccine developed with Merck.

Robert Langer, who is believed to retain roughly a 3% stake in Moderna, saw the estimated value of his holding rise to about $1.7 billion by Wednesday, from around $730 million a day earlier. His stake had been valued at roughly $343 million when Moderna shares hit a low of $29.81 on January 2.

Merck shares climbed more than 10% in morning trading, while Moderna's stock soared over 120%. The size of those moves reflect the companies' relative size entering Wednesday: ...