PTC Therapeutics has crossed from a fading Duchenne franchise into a phenylketonuria launch company, and the second quarter is the first clean print of that identity. Sephience, the oral sepiapterin therapy for phenylketonuria, now supplies the majority of product sales and is the reason management raised full-year product guidance for a second time. The equity case is no longer whether the launch works. It is whether one new metabolic drug, plus a partnered Huntington program and a bankruptcy-auction gene therapy, can replace two structurally impaired Duchenne products and support a mid-cap rare-disease multiple.
Product sales more than doubled from the year-ago quarter, and Sephience did the heavy lifting. Sequential growth on that franchise came from United States demand first and a widening international footprint second, while Translarna and Emflaza kept sliding along the path the annual filing already described. A Novartis development milestone for the INVEST-HD start padded collaboration revenue and helped produce a profitable quarter, but that check is not a run-rate. The mix is the story: the new drug is carrying the P&L while the old franchise is being written down in slow motion.
Cash and marketable securities sit above two billion after a zero-coupon convertible refinance that pushed most near-term note risk into the next decade. The remaining debate is duration. Can Sephience keep adding patients fast enough to outrun the Duchenne fade, and does the second-half conversation with the Food and Drug Administration on votoplam open a real Huntington path, or does the stock stay a single-product launch multiple?