House lawmakers have issued a subpoena to compel former Turing Pharmaceuticals... (Associated Press) 
 
 The House Committee on Oversight and Government Reform is investigating several companies for exorbitant drug price increases, including embattled Canadian drugmaker Valeant Pharmaceuticals. When asked about the hearing and whether he would attend, Mr. Shkreli wrote in an email, “I made it clear that you are not to contact me ever again.” 
 
 But in a posting on Twitter later in the day, Mr. Shkreli wrote: “House busy whining to health care reporters about me appearing for their chitchat next week. The letter, signed by Representatives Jason Chaffetz, a Republican of Utah and the committee’s chairman, and its top Democrat, Elijah Cummings of Maryland, also asked for “copies of all documents previously produced” in response to requests from other government agencies.
– Martin Shkreli "loves to talk," notes the New York Times, but the ex-Turing Pharmaceuticals CEO has taken the Fifth as a Senate committee looks into drug-pricing practices—and his refusal to hand over subpoenaed documents could impede the probe, NBC News reports. "Absent a valid justification for the grounds for invoking the Fifth Amendment, Mr. Shkreli's assertion could hinder our investigation," Maine Sen. Susan Collins, chair of the Senate's Special Committee on Aging, tweeted Wednesday. To which Shkreli responded later Wednesday night: "@SenatorCollins I have valid justification. Are you serious? I have constitutional rights. No wonder trust in the US Government is at a low." This development comes just days before Shkreli's subpoena-mandated appearance Tuesday at a hearing of the House Committee on Oversight and Government Reform, which is looking into several companies accused of excessively hiking prices, the AP reports. "I have been trying for the better part of a year to get information from Martin Shkreli about his outrageous price increases, and he has obstructed our investigation at every turn," Maryland Rep. Elijah Cummings said in a statement Wednesday, per CNNMoney. Shkreli dished about the upcoming hearing on Twitter Wednesday, posting a pic of what appeared to be the House subpoena and striking back at Cummings. "House busy whining to healthcare reporters about me appearing for their chit chat next week. Haven't decided yet. Should I? @RepCummings," he tweeted. "He claims publicly that he wants to explain to Congress how drug pricing works. On Tuesday, he will get his chance," Cummings said in his statement. When asked by the Times if he would be at Tuesday's hearing, Shkreli emailed, "I made it clear that you are not to contact me ever again." In related news, Shkreli's lawyers put in paperwork Tuesday indicating that he wants to replace them, NBC notes. (More to the point: What's it like to date Martin Shkreli?)