Activist investor William Ackman has made an unorthodox alliance with a serial acquirer of specialty drugs to try buying the maker of Botox.
Mr. Ackman and Valeant Pharmaceuticals International Inc. seek to acquire the wrinkle treatment's maker, Allergan Inc., according to a filing on Monday with the Securities and Exchange Commission….
Mr. Ackman's Pershing Square Capital Management LP has built a 9.7% stake in Allergan since February, according to the SEC filing. Valued at about $4 billion, the stake represents his biggest investment ever, people familiar with the matter said….
The strange bedfellows came together after Mr. Ackman was introduced to Valeant by a Pershing Square employee who knows Valeant Chief Executive Michael Pearson. Mr. Ackman suggested he could help the Canadian company do a deal at some point.
Valeant and Mr. Ackman later signed an agreement in February to work together; Valeant told him it was interested in Allergan, of Irvine, Calif.