Zenas BioPharma, Inc. filed a Form 8-K on November 6, 2026, reporting the termination of its prior at-the-market offering prospectus supplement and the concurrent filing of a new prospectus supplement covering up to $200,000,000 in common stock under its existing Sales Agreement with Jefferies LLC.

Key Highlights

  • Prior supplement terminated: The company disclosed that the offering under the Prior Prospectus Supplement has been terminated and no further sales will occur under it.
  • Shares sold to date: According to the filing, approximately $153.2 million of shares had been sold under the Prior Prospectus Supplement as of November 6, 2026.
  • Remaining capacity unused: Approximately $46.8 million of shares remained unsold under the Prior Prospectus Supplement at the time of termination.
  • New supplement filed: On November 6, 2026, the company filed an additional prospectus supplement for the offer and sale of shares with an aggregate offering price of up to $200,000,000.
  • Sales Agreement unchanged: The new supplement operates under the same Sales Agreement with Jefferies LLC, originally entered into on October 8, 2025.
  • Legal opinion provided: Ropes & Gray LLP issued a legal opinion relating to the new prospectus supplement shares, attached as Exhibit 5.1 to the filing.
  • Emerging growth company: The filing indicates Zenas BioPharma, Inc. is classified as an emerging growth company under applicable SEC rules.

Zenas BioPharma Resets Its At-the-Market Common Stock Offering Program

Zenas BioPharma, Inc. (NASDAQ:ZBIO), a Delaware-incorporated biopharmaceutical company headquartered at 852 Winter Street, Suite 250, Waltham, MA, disclosed in its November 6, 2026 Form 8-K that it has reset its at-the-market equity offering program. The company previously entered into a Sales Agreement with Jefferies LLC on October 8, 2025, under which shares of common stock (par value $0.0001 per share) could be offered and sold from time to time at the company's sole discretion. The initial prospectus supplement filed alongside a Form S-3ASR registration statement (File No. 333-290777) authorized aggregate sales of up to $200,000,000 in common stock.

According to the filing, as of November 6, 2026, the company had sold approximately $153.2 million of shares under the Prior Prospectus Supplement, leaving approximately $46.8 million unsold. Rather than continuing under the prior supplement, the company filed a new prospectus supplement on the same date, also covering up to $200,000,000 in common stock, while simultaneously terminating the Prior Prospectus Supplement. The filing states that "the Company will not make any further offer or sale of Shares pursuant to the Prior Prospectus Supplement."

The new prospectus supplement shares will be offered and sold pursuant to the same Registration Statement, which the filing notes "became automatically effective upon filing." The company's outside counsel, Ropes & Gray LLP, issued a legal opinion in connection with the new supplement shares, which is attached as Exhibit 5.1 to the current report. The Form 8-K was signed by Joseph L. Farmer, President and Chief Operating Officer, on behalf of the registrant. The company also noted that the filing does not constitute an offer to sell or a solicitation to buy any new prospectus supplement shares.

What Was Disclosed

Zenas BioPharma filed an 8-K on November 6, 2026, disclosing the termination of its prior at-the-market prospectus supplement after approximately $153.2 million in sales and the launch of a new prospectus supplement permitting up to $200,000,000 in additional common stock sales through Jefferies LLC.