Switching Debt with Zero-Interest Convertible Bonds: Rare Disease Biotech Executives Sell Shares

Eric Pauwels, Chief Business Officer of PTC Therapeutics, Inc. (PTCT)—a U.S. biotech firm focused on rare diseases—disclosed on June 10 that, under a 10b5-1 trading plan, he exercised stock options and sold tens of thousands of shares at about $75 each. He also sold a portion of his existing holdings but continues to directly hold roughly 73,000 shares.

At the same time, PTC Therapeutics set the pricing for a private Rule 144A offering of $500 million 0% convertible notes due June 15, 2031 (approximately KRW 700 billion). Of the roughly $486.8 million (about KRW 680 billion) in expected net proceeds, the company plans to use approximately $328.8 million (around KRW 460 billion) to cash-purchase $222 million (about KRW 310 billion) of its 1.5% convertible notes maturing in 2026. The balance will fund general corporate purposes and additional debt repayment. The new notes carry a conversion price of $107.48—a 40% premium to the June 15 closing price—and bear no interest. The offering is scheduled to close on June 18 and is open only to qualified institutional buyers. (Source: streetinsider.com)

In its May 7 Q1 2026 earnings report, the company announced total revenues of $272.6 million, noting a 36% sequential increase in quarterly sales since the launch of its rare-disease therapy “Sephience.” In light of the growing product portfolio, PTC Therapeutics raised its full-year revenue guidance. (Source: ir.ptcbio.com)

PTC Therapeutics is a publicly traded U.S. biopharmaceutical company that develops and commercializes oral and gene-based therapies for patients with rare and genetic diseases. Its portfolio includes royalties from the spinal muscular atrophy treatment Evrysdi and therapies for Duchenne muscular dystrophy. To expand its rare-disease pipeline, the company has broadened partnerships with major pharmaceutical firms. In 2024, it signed a licensing agreement with Novartis for a Huntington’s disease drug candidate potentially worth up to several billion dollars, exemplifying its collaborative approach to R&D and commercialization. (Source: ir.ptcbio.com)