You don't understand the terms of the preferred shares. They get paid off now because the redemption rate goes up if they don't. They paid off the first preferred shares shortly before doing the deal for the second batch.
They have never dipped into the cash raised last year from either the secondary offering or the latest preferred share deal. Once again... you don't try to raise cash when you need it or all you get is hard-money terms. They can't have the perception of dwindling cash or nobody would do a licensing deal with them. They would just wait them out until they ran out of cash.