--- title: "MBX Biosciences files for 10,000,000-share offering" url: "https://aibio.space/news/mbx-biosciences-files-10-000-000-share-offering-later-sells-11-108-055/" publisher: "aibio.space (Biotech Investor Relations News)" date: "2025-09-22" section: "Financings" tickers: "TSX:MBX" source: "https://www.sec.gov/Archives/edgar/data/1776111/000119312525211320/mbx-20250922.htm" summary: "MBX Biosciences filed an S-1 on September 22, 2025 for 10,000,000 shares. The deal priced on September 24 at $18.00 for 11,108,055 shares and closed on Sep" --- By the aibio.space news desk. Sources - [MBX Biosciences, Inc. S-1 (2025-09-22)](https://www.sec.gov/Archives/edgar/data/1776111/000119312525211320/mbx-20250922.htm) - [MBX Biosciences, Inc. 424B4 (2025-09-25)](https://www.sec.gov/Archives/edgar/data/1776111/000119312525217429/424b4_final_prospectus_s.htm) - [MBX Biosciences, Inc. 8-K (2025-09-26)](https://www.sec.gov/Archives/edgar/data/1776111/000119312525220432/mbx-20250924.htm) [MBX](https://aibio.space/companies/microbix-biosystems/) 2025-09-22 # MBX Biosciences files for 10,000,000-share offering, later sells 11,108,055 at $18.00 Tickers [MBX](https://aibio.space/companies/microbix-biosystems/) MBX Biosciences filed an S-1 on September 22, 2025 for 10,000,000 shares. The deal priced on September 24 at $18.00 for 11,108,055 shares and closed on September 26 with net proceeds of about $187.5 million. ## Key facts - **Company**: Microbix Biosystems Inc. (TSX: MBX) - **News type**: Financings - **Primary source**: [MBX Biosciences, Inc. S-1 (2025-09-22)](https://www.sec.gov/Archives/edgar/data/1776111/000119312525211320/mbx-20250922.htm) *A conference room set for a meeting. CC0, via rawpixel. The picture shows the field, not the companies named.* ## The filing and the pricing MBX Biosciences, Inc., a Carmel, Indiana company whose shares trade on the Nasdaq Global Select Market under the symbol MBX, filed a registration statement on Form S-1 on September 22, 2025. It proposed to sell 10,000,000 shares of common stock in an underwritten public offering. The preliminary prospectus gave the last reported sale price as $10.00 per share on September 19, 2025, and offered the underwriters a 30-day option on 1,500,000 additional shares. The deal was upsized. On September 24, 2025, the company signed an underwriting agreement for 11,108,055 shares at $18.00 per share. The final prospectus, dated that day, gave the last reported sale price on September 24 as $20.10. The offering closed on September 26, 2025. The public offering price totaled $199,944,990. Underwriting discounts and commissions were $1.08 per share, or $11,996,699, leaving proceeds before expenses of $16.92 per share, or $187,948,291. The company said net proceeds were approximately $187.5 million after discounts, commissions and expenses. The underwriters hold a 30-day option on up to 1,666,208 more shares, which would lift net proceeds to $215.7 million if exercised in full. ## Banks, counsel and dilution J.P. Morgan Securities LLC and Jefferies LLC acted as joint book-running managers and as representatives of the underwriters. The prospectus lists the other underwriters and their commitments: TD Securities (USA) LLC for 1,999,450 shares, Guggenheim Securities, LLC for 1,332,966, Citizens JMP Securities, LLC for 555,403 and Oppenheimer & Co. Inc. for 555,403. J.P. Morgan took 3,998,900 shares and Jefferies 2,665,933. Goodwin Procter LLP and Davis Polk & Wardwell LLP appear as counsel on the S-1 cover. The documents do not name a placement agent or a separate financial advisor. The company agreed to reimburse the underwriters for up to $40,000 of FINRA clearance expenses and estimated its other offering expenses at about $480,000. New buyers took on immediate dilution. The prospectus puts it at approximately $8.90 per share in as adjusted net tangible book value, against historical net tangible book value of $6.53 per share at June 30, 2025. After the sale the company expected 44,700,281 shares outstanding, or 46,366,489 if the option is exercised in full. The company, its directors and executive officers, and certain significant shareholders signed lock-up agreements, 90 days for the company and 75 days for the others, which J.P. Morgan and Jefferies can release early. ## What the money funds, and the data behind the price MBX said it will use the proceeds, with existing cash, cash equivalents and short-term investments, mainly to advance its three clinical-stage programs and to fund discovery research, additional clinical development and general corporate purposes. At June 30, 2025, it had cash, cash equivalents and marketable securities of $224.9 million and an accumulated deficit of $180,796 thousand. For the six months ended June 30, 2025, it reported a net loss of $43,291 thousand, compared with $28,194 thousand a year earlier. The filing gives no date for when cash would run out. The raise followed Phase 2 data. On September 22, 2025, the company announced topline results from the Avail trial of its lead candidate, canvuparatide, a once-weekly parathyroid hormone prodrug for chronic hypoparathyroidism. All 64 patients completed the 12-week study. The primary composite endpoint was met by 63% of treated patients (30/48) against 31% on placebo (5/16), with p=0.042. The placebo arm held only 16 patients, so the comparison is small. In the open-label extension, 79% of 56 evaluable patients were responders at six months, but that phase had no placebo comparison. On safety, the company said no drug-related serious adverse events were reported and no one stopped treatment because of canvuparatide. Injection site reactions occurred in 19% of the pooled treatment group against 13% on placebo. The company plans to start a Phase 3 trial in 2026, so pivotal data and any approval filing remain well ahead. Imapextide, a long-acting GLP-1 receptor antagonist for post-bariatric hypoglycemia, showed a median half-life of 90 hours in Phase 1. That figure shows exposure, not efficacy. The company said it expected to start a Phase 2a trial in the third quarter of 2025. The terms are in the [final prospectus](https://www.sec.gov/Archives/edgar/data/1776111/000119312525217429/424b4_final_prospectus_s.htm) and the company's [Form 8-K](https://www.sec.gov/Archives/edgar/data/1776111/000119312525220432/mbx-20250924.htm). [Report an error](https://aibio.space/reputation/#correction) ## Companies in this story MBX Microbix Biosystems Inc. TSX ยท Canada Open the starter desk ## More in Financings Financings ### [INmune Bio raises $4.50 million in registered direct offering with warrants](https://aibio.space/news/inmune-bio-raises-4-50-million-registered-direct-offering-warrants/) Oct 29, 2026 Financings ### [Lexeo Therapeutics files $300 million shelf registration](https://aibio.space/news/lexeo-therapeutics-files-300-million-shelf-registration/) Oct 29, 2026 Financings ### [ProKidney files $650 million shelf with $200 million Jefferies sales program](https://aibio.space/news/prokidney-files-650-million-shelf-200-million-jefferies-sales-program/) Oct 29, 2026 --- Source page: https://aibio.space/news/mbx-biosciences-files-10-000-000-share-offering-later-sells-11-108-055/. Facts in aibio.space stories are checked against company filings and releases; opinion is labelled. Cite as: aibio.space, "MBX Biosciences files for 10,000,000-share offering", 2025-09-22, https://aibio.space/news/mbx-biosciences-files-10-000-000-share-offering-later-sells-11-108-055/