For the past few years, Al Mann insisted that his Afrezza inhaled insulin device would be a winner. And the Los Angeles billionaire repeatedly bet part of his own fortune on winning FDA approval, despite skepticism that such a device may not gain acceptance and, more specifically, changes in strategy and hyperbolic statements that set some Wall Streeters on edge (look here).

Now, less than three weeks after the FDA issued yet another complete response letter (see here), Mann appears to have finally given up. Actually, he used slightly different language. To wit, MannKind reported a loss for the year; disclosed plans to lay off 179 employees or 41 percent of its workforce, and now has less than a year’s worth of cash left (see statement).

In the past, cash was not a problem. Mann would simply open his personal vaults and throw a few hundred million into the MannKind treasury. But the FDA wants more clinical trials and this takes still more money. In a conference call late yesterday, Mann insisted plans are under way to run those trials. But then analysts asked about financing options. MannKind cfo Matt Pfeffer attempted to sound optimistic by saying, “we are blessed in having a lot of different potential opportunities.”

But the response from the billionaire was telling. When asked about investing more of his own funds, Mann gave a reply that is unlikely to inspire confidence from shareholders. “I can’t make any commitments at this point,” he said. “Obviously, I believe in this product and I have invested in it because I believe in it and I have to find a solution.”

Well, what should be obvious is that if Mann is unwilling to invest more money, why should anyone else? As The Street noted, the conference call should have ended at that point. Mann deserves credit for trying to develop a product to improve health and bet some of his fortune, but at this point, everyone needs to inhale just a little and recognize that MannKind may finally be frozen in its tracks.