Citi analyst Joel Beatty found comments online from U.S. Congressman Collin Peterson that voice support for approval of PTC Therapeutics' (PTCT) Duchenne muscular dystrophy treatment ataluren, which is also known as Translarna. The document appears to have been posted last Thursday in response to the FDA's request for comments regarding its advisory panel meeting scheduled for September 28, and is written in the form of a speech to be given at the meeting, Beatty told investors Friday night in a research note. The analyst confirmed from the Congressman's office that a legislative assistant plans to read the letter on behalf of Rep. Peterson at the September 28 advisory meeting. The comments mention a constituent of Rep. Peterson's with DMD who will be in the audience and for whom "access to ataluren has allowed him to live and thrive well into his 20s with no side effects," Beatty cites the statement as saying. It added, "The full consideration of ataluren not only fulfills the Congressional intent of FDASIA and the 21st Century Cures Act, but also has the potential to save lives across the nation." Beatty believes political support could play a role in the FDA's review of Translarna. The analyst notes that Sarepta Therapeutics' DMD drug Exondys 51 was approved after favorable political support. Beatty sees $20 of upside potential in PTC shares, with only $3 downside risk, around the FDA panel meeting. The analyst has a Buy rating on the shares with a $28 price target. The stock closed Friday up 18c to $20.93. A positive panel vote will likely lead to FDA approval while a negative vote doesn't necessarily mean the FDA will not approve the drug, Beatty argues. His model assumes a 25% probability of success for Translarna.