Schwarz Pharma looks set to receive a $100 million license fee from Pfizer after the US Federal Trade Commission gave the go-ahead for the latter’s purchase of its overactive bladder drug fesoterodine.

Schwarz said in April that it could get $210 million plus royalties from licensing fesoterodine, which has already been filed for approval with both the US Food and Drug Administration and the European Medicines Agency (EMEA). An additional $110 million is dependent on approvals and other milestones.

The anti-muscarinic agent has peak sales potential of around 450 million euros ($548m) a year, according to the German company.

The licensing deal was part of a settlement of patent litigation between Schwarz and Pfizer, which sells a similar drug for overactive bladder called Detrol (tolterodine). Detrol and a once-daily version, Detrol LA, are approaching blockbuster status with combined sales of $988 million last year.

Under the terms of that agreement, Schwarz will be entitled to receive royalties on the combined sales of fesoterodine and Pfizer's current Detrol product line.