Cleveland BioLabs turned profitable during the fourth quarter as a big drop in the liability the Buffalo-based life sciences faces for the warrants it has issued for its stock offset continued losses from its drug development operations.

Cleveland BioLabs reported a profit of $2.2 million, or 7 cents per share, during the fourth quarter, which was a major improvement from its loss of $7.7 million, or 20 cents per share, a year ago.

But all off the profit came from a $7.8 million reduction in the liability the company faces from its stock warrants, which plunged in value because of the steep drop in the value of Cleveland BioLabs stock. The warrants are revalued at the end of each quarter.

Excluding that change, the company’s operations lost $5.6 million during the quarter, slightly less than its loss of $6.4 million a year ago.