Amlyin Pharmaceuticals (AMLN) implied volatility is crashing after the company received a complete response letter from the FDA related to exenatide once weekly. In a conference call, the company said it expects product approval once issues are addressed. Shares touched a new 52-week high and are up $1.66 to $21.92 on the news. Trading in the options is active, with 14K calls and 8450 puts, incuding a recent seller of 1100 Mar 21 calls at $1.25. Meanwhile, implied volatility has plummeted about 155 percent, back to the mid 50s, now that this event risk has passed.