aibioPrime Medicine prices 38,000,000 share offering at $3.30, $125,400,000 gross
Tickers PRME
Prime sold 38,000,000 shares at $3.30, below the $3.83 closing price on July 29, 2025. The estimated net proceeds are $120.2 million, and the auditor's 2024 report carries a going-concern paragraph.
Key facts
- Company
- Prime Medicine, Inc. (NASDAQ: PRME)
- News type
- Financings
- Primary source
- Prime Medicine, Inc. 424B5 (2025-07-30)
Banks, counsel and terms
Prime Medicine, Inc. priced an underwritten public offering of 38,000,000 shares of common stock at $3.30 per share, for gross proceeds of $125,400,000. The underwriting agreement was signed on July 30, 2025. TD Securities (USA) LLC and BMO Capital Markets Corp. are the representatives of the underwriters. TD Cowen and BMO Capital Markets are the joint book-running managers. TD Securities is committed to buy 30,400,000 shares and BMO Capital Markets Corp. 7,600,000.
Underwriting discounts and commissions are $0.198 per share, or $7,164,000.16 in total. That leaves $3.102 per share, or $118,235,999.84, before expenses. The underwriters take no discount on 1,818,181 shares sold to the Cystic Fibrosis Foundation. They also hold a 30-day option on up to 5,700,000 more shares.
Goodwin Procter LLP of Boston passes on the validity of the shares for Prime. Paul Hastings LLP of New York is counsel to the underwriters. The shares are sold under a Form S-3 shelf that the SEC declared effective on November 13, 2023 and that covers up to $500,000,000 of securities.
The price and the share count
The offering price compares with a closing price of $3.83 on the Nasdaq Global Market on July 29, 2025. Before the deal, Prime had 131,160,842 shares outstanding as of March 31, 2025. Options over 15,919,190 shares were outstanding at that date, at a weighted average exercise price of $7.20 per share. The offering price is well below that weighted average exercise price.
Prime says it estimates net proceeds of about $120.2 million, or about $138.2 million if the underwriters exercise their option in full. It plans to use them, with existing cash and investments, mainly for research and development on its Wilson's Disease and Alpha-1 antitrypsin deficiency (AATD) programs. The rest goes to working capital, capital expenditures and general corporate purposes.
The going-concern warning
The auditor is PricewaterhouseCoopers LLP. Its report on the 2024 financial statements contains an explanatory paragraph on the company's ability to continue as a going concern. The prospectus lists that ability among its forward-looking statements.
Prime also gives a preliminary, unaudited cash figure for June 30, 2025. It says cash, cash equivalents, short-term investments and related party short-term investments were about $101.8 million, excluding about $13.7 million of restricted cash.
What the spending looks like
The 2024 annual report shows research and development expenses of $155,289 thousand, up $7.4 million from 2023. The company attributes the rise mainly to an $11.3 million increase in facility expense, from the expansion of its laboratory space, and an $8.9 million increase in personnel expense. General and administrative expenses were $50,161 thousand in 2024. In January 2024 Prime also paid Myeloid $13.5 million under a settlement of two arbitrations over a license agreement.
Clinical expense in the research line was $4,135 thousand, tied to PM359, its candidate for chronic granulomatous disease.
The programs and their dates
Prime says it will now focus on its in vivo liver franchise, which targets Wilson's Disease and AATD. The company describes both programs as in late stages of pre-clinical development. It says they are on track for IND and/or CTA filings in the first half of 2026 for Wilson's Disease and in the middle of 2026 for AATD. Both depend on those filings and on the money from this deal.
Prime also continues an in vivo Cystic Fibrosis program and a Prime Edited CAR-T effort with Bristol-Myers Squibb Company. In July 2025 the Cystic Fibrosis Foundation agreed to provide up to $24 million in additional funding for it.
What comes next
The next dated steps are the Wilson's Disease filing in the first half of 2026 and the AATD filing in mid-2026. Both programs are pre-clinical, so no human data exist for either.