Having signed on as the commercial partner for MannKind Corp.'s Afrezza inhaled insulin, Sanofi is clearly betting it can succeed where Exubera inhaled insulin from Pfizer Inc. and Nektar Therapeutics failed. To make the numbers add up for its investors, the biotech has to hope the pharma is right.

Under last week's deal, Sanofi will pay $150 million up front and take over responsibility for global commercial, regulatory and development activities for Afrezza, which FDA approved in June to improve glycemic control in Type I and II diabetics. MannKind is eligible for up to $775 million in development, regulatory and sales milestones. The companies will split costs and profits, with Sanofi receiving 65% and MannKind 35%. Sanofi also agreed to advance up to $175 million at 8.5% interest to MannKind to cover its share of the collaboration's expenses.