Rare Disease New Drug Executive Sells $20 Million Stock Options, Retains $20 Million Stake

Harold Bernstein, Executive Vice President of Research & Development and Chief Medical Officer at Maze Therapeutics, Inc. (NASDAQ: MAZE), a developer of novel therapies for rare kidney diseases, exercised 30,000 stock options on March 10 and sold the same number of common shares on the open market, securing approximately $1.51 million (around KRW 2 billion) in proceeds and realizing about $1.2 million (KRW 1.6 billion) in intrinsic gain, according to a recent SEC filing.

Following this transaction, Bernstein still holds 300,000 common shares, representing a stake valued at roughly $15.13 million (KRW 20 billion).

In its Q4 and full-year 2025 financial results announced March 25, Maze reported positive topline data from the Phase 2 HORIZON trial of MZE829 in APOL1-mediated kidney disease, recognized a $20 million milestone payment from Shionogi, ended the year with $360 million in cash and cash equivalents, recorded a net loss of $131.1 million, appointed Dr. Neil Kumar (CEO of BridgeBio) as a new board member, and affirmed that its current cash runway is expected to extend through 2028.

Following that announcement, U.S. financial and biotech media have spotlighted Maze’s kidney and metabolic disease pipeline and clinical development plans, particularly the HORIZON Phase 2 data and its $360 million cash reserves.

SEC filings further show that Bernstein made additional share disposals on March 20 under a 10b5-1 trading plan established in late 2025.

Maze Therapeutics is a clinical-stage biotech leveraging human genetics to develop oral small-molecule precision medicines for kidney, cardiovascular, and metabolic diseases. Its core pipeline comprises MZE829, a dual-mechanism APOL1 inhibitor for APOL1-mediated kidney disorders, and MZE782, an SLC6A19 inhibitor targeting phenylketonuria and chronic kidney disease.

The company raised about $140 million in its February 2025 Nasdaq IPO, secured $150 million through a private placement in September 2025, and arranged a $200 million secured loan facility in early 2026 to support ongoing clinical development.