Allergan Inc.’s (NYSE:AGN) board Monday rejected an unsolicited takeover proposal by Valeant Pharmaceuticals International, Inc. (NYSE:VRX) worth $45.7 billion, stating that the deal undervalued the Botox-maker.

Allergan said in a statement Tuesday that Canada-based Valeant’s proposal not only undervalued the Irvine, Calif.-based company, but also created significant risks and uncertainties for the company and its stockholders. Valeant had offered to acquire Allergan on April 22 for $48.30 a share in cash and a stock swap of 0.83 of its common share for each Allergan share, which added up to a valuation of $152.88 a share, which was at a premium of over 7 percent to Allergan’s stock price at the time.

“After careful review and consideration, our Board of Directors has unanimously determined that Valeant's unsolicited proposal substantially undervalues Allergan and does not reflect the value of the Company's leading market positions, sales and marketing foundation, industry-leading research and development efforts, as well as future revenue and earnings growth," David E.I. Pyott, Allergan's chairman and CEO, said in the statement.

Pyott also wrote a letter to Valeant’s Chairman and CEO Michael Pearson, according to the statement, where he asked for more clarity on Valeant's plans to cut costs “without harming the long term viability and growth trajectory of our business,” adding that the strategy that Valeant follows counters Allergan’s approach.

“We are disappointed that Allergan has rejected our value-creating offer without engaging in any substantive discussions with Valeant or Allergan's largest stockholder, Pershing Square, and we remain committed to pursuing this transaction,” Laurie Little, Valeant’s spokesperson, said according to Fox News.

The bid was handled by New York-based Pershing Square Capital Management, which is headed by William Ackman.

“We believe Allergan is in a great spot,” David Maris, an industry analyst at BMO Capital Markets Corp. in New York, said in a note, according to Bloomberg, adding: "Valeant’s prospects of completing this deal are less than 50 percent.’’