MBX Biosciences, Inc.·4

May 11, 4:01 PM ET

Azoulay Salomon 4

4 · MBX Biosciences, Inc. · Filed May 11, 2026

Research Summary

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MBX Biosciences CMO Azoulay Salomon Exercises Options, Sells Shares

What Happened

  • Azoulay Salomon, Chief Medical Officer of MBX Biosciences (MBX), exercised stock option/derivative positions and sold the resulting shares on May 8, 2026. The filing shows exercises of 55,000 shares at $10.46 ($575,300) and 15,003 shares at $16.00 ($240,048), plus additional derivative conversions reported at $0.00. On the same day she sold 55,000 shares at a weighted average price of $38.38 (proceeds $2,110,900) and 15,003 shares at $38.30 (proceeds $574,615). Total reported sale proceeds ≈ $2,685,515.
  • The sales were executed pursuant to an approved Rule 10b5‑1 trading plan adopted January 27, 2026 (footnote F1).

Key Details

  • Transaction date: May 8, 2026; Form filed May 11, 2026 (timely).
  • Exercises/Acquisitions: 55,000 @ $10.46 = $575,300; 15,003 @ $16.00 = $240,048; plus 70,003 shares reported as acquired at $0.00 (derivative conversions).
  • Sales/Dispositions: 55,000 @ $38.38 (weighted avg) = $2,110,900; 15,003 @ $38.30 (weighted avg) = $574,615. Combined sold = 70,003 shares, total ≈ $2.69M.
  • Price range: the weighted-average sale prices reflect multiple trades at prices from $35.00 to $41.26 (footnotes F2/F3).
  • Vesting/option notes: one option tranche had 25% vesting on June 24, 2025; another had 25% vesting on Sept 12, 2025, with the remaining 75% vesting in 36 monthly installments thereafter (F4, F5).
  • Shares owned after the transactions are not specified in the provided excerpt of the filing.

Context

  • This was an exercise-and-sell (cashless-style) sequence: options/derivatives were exercised and shares were sold the same day under a pre‑approved 10b5‑1 plan, which is a preset trading arrangement that can limit insider timing discretion.
  • Such routine insider sales often reflect option exercise and liquidity needs rather than a view on company fundamentals; the filing is factual and does not state motivation.

Insider Transaction Report

Form 4
Period: 2026-05-08
Azoulay Salomon
Chief Medical Officer
Transactions
  • Exercise/Conversion

    Common Stock

    [F1]
    2026-05-08$10.46/sh+55,000$575,30069,769 total
  • Sale

    Common Stock

    [F1][F2]
    2026-05-08$38.38/sh55,000$2,110,90014,769 total
  • Exercise/Conversion

    Common Stock

    [F1]
    2026-05-08$16.00/sh+15,003$240,04829,772 total
  • Sale

    Common Stock

    [F1][F3]
    2026-05-08$38.30/sh15,003$574,61514,769 total
  • Exercise/Conversion

    Stock option (right to buy)

    [F4]
    2026-05-08+55,000194,540 total
    Exercise: $10.46Exp: 2034-08-02Common Stock (55,000 underlying)
  • Exercise/Conversion

    Stock option (right to buy)

    [F5]
    2026-05-08+15,00330,008 total
    Exercise: $16.00Exp: 2034-09-12Common Stock (15,003 underlying)
Footnotes (5)
  • [F1]The sales reported on this Form 4 represent the exercise and sale of common stock options by the reporting person pursuant to an approved Rule 10b5-1 trading plan adopted on January 27, 2026.
  • [F2]The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $35.00 to $41.26, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.
  • [F3]The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $35.00 to $41.26, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.
  • [F4]25% of the shares underlying this option vested and became exercisable on June 24, 2025, with the remaining 75% vesting in thirty-six (36) substantially equal monthly installments thereafter, subject to the Reporting Person's continued service on each such vesting date.
  • [F5]25% of the shares underlying this option vested and became exercisable on September 12, 2025, with the remaining 75% vesting in thirty-six (36) substantially equal monthly installments thereafter, subject to the Reporting Person's continued service on each such vesting date.
Signature
/s/ P. Kent Hawryluk, attorney-in-fact|2026-05-11

Documents

1 file
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    ownership.xmlPrimary

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