DUBLIN – Translate Bio Inc. is the first beneficiary to gain from Sanofi SA’s massive $11.7 billion addition to its balance sheet, following its recent disposal of its holdings in long-time partner Regeneron Pharmaceuticals Inc. Lexington, Mass.-based Translate Bio is getting $300 million up front, another $125 million in equity investment and up to $1.9 billion in milestones under a major expansion of an existing agreement with Paris-based Sanofi to develop mRNA-based vaccines for infectious disease.