Alfred Mann has made good on his word.

The billionaire biotech entrepreneur had vowed to finance his latest public company, MannKind Corp., “to the end” in order to get its most promising product, an inhaled form of insulin, to the market.

Last week, Mann, its chairman and principal stockholder, agreed to contribute another $87.5 million to the Valencia-based developmental stage pharmaceutical company, which has hit some obstacles in its quest to develop the insulin product.

Mann’s investment is part of a $175 million private placement agreement MannKind struck last week; institutional investors agreed to provide the other $87.5 million. MannKind is issuing new common shares and warrants for additional shares.

The funding is critical in financing the final phase of clinical trials for MannKind’s lead product, Technosphere, the inhaled insulin under development. Analysts estimate that at least $200 million will be required to finish the trials.

MannKind also is developing a drug to treat solid-tumor cancers and is working on treatments for inflammatory and auto immune diseases.