Boundless Bio, Inc. filings document a clinical-stage oncology issuer focused on ecDNA-directed cancer therapeutics, with formal disclosures on operating results, research programs, and material events. Recent 8-K reports furnish quarterly and annual financial results and business updates for BBI-940, KOMODO-1, and the discontinued POTENTIATE program involving BBI-355 and BBI-825.
Its proxy and current reports also cover board composition, director elections, auditor ratification, stockholder voting results, and facility-related obligations, including lease-termination arrangements. These filings frame the company’s clinical-development disclosures, public-company governance, capital allocation, and operating obligations.
Boundless Bio disclosed ownership by Tang-linked investors totaling 11.3%. The Schedule 13G states 2,533,845 shares are beneficially owned collectively by Tang Capital Management, Kevin Tang and affiliated entities, based on 22,474,777 shares outstanding as of June 15, 2026.
The filing lists shared voting and dispositive power across Tang Capital Management, Tang Capital Partners, Tang Capital Partners International, Tang Capital Partners III, Tang Capital Partners IV and Kevin Tang; signatures are dated June 29, 2026.
Boundless Bio, Inc. insider entities affiliated with Tang Capital reported multiple open-market purchases of Common Stock. Across June 25–29, 2026, they bought a net 286,333 shares at weighted-average prices generally between about $2.40 and $2.60 per share.
Individual trades ranged from 134 shares to 145,880 shares per transaction, with reported per-share prices such as $2.48, $2.47, $2.54, $2.55 and $2.56. The positions are held indirectly "By LP" through Tang Capital limited partnership vehicles.
According to the filing, Tang Capital-related entities beneficially own 580,669, 791,839, 580,668 and 580,669 shares in four affiliated vehicles, for an aggregate beneficial holding of 2,533,845 shares after these purchases. Kevin Tang has a pecuniary interest in these indirectly held shares.
Boundless Bio, Inc. insider filings show that entities affiliated with Tang Capital report initial beneficial ownership of the company’s common stock. The Form 3 indicates indirect holdings of 2,247,512 shares of common stock, held by limited partnership and corporate vehicles associated with Tang Capital.
Kevin Tang is described as the sole manager or director of these entities and has a pecuniary interest in the shares they beneficially own. The filing is an initial ownership report and does not show any new purchases or sales of Boundless Bio stock.
Boundless Bio (BOLD) agreed to merge with Serapha Bio under an Agreement and Plan of Merger dated June 22, 2026. On a pro forma, fully diluted basis, Serapha equityholders are expected to own approximately 96.31% of the combined company and pre‑Merger Boundless Bio equityholders approximately 3.69%. The transaction contemplates a Form S-4 filing, a reverse stock split and an increase in authorized shares, and is conditioned on stockholder approvals, Nasdaq listing approval and a $200 million minimum cash raise in Serapha’s Securities Purchase Agreement.
Concurrent financings include a Series A preferred financing of ~$138.0 million and a PIPE Pre-Closing Financing of ~$92.0 million. Boundless Bio announced a workforce reduction of approximately 75%, with estimated one‑time charges of $3.0 million to $5.0 million, largely to be recognized in Q3 2026. Management and board composition of the combined company will be determined by Serapha.
Boundless Bio agreed to an all-stock merger with private biotech Serapha Bio, creating a combined company focused on Serapha’s in vivo base-editing therapy SERP-01 for Alpha‑1 Antitrypsin Deficiency. Based on the merger exchange ratio, Serapha equityholders are expected to own about 96.3% of the combined company on a fully diluted basis, with Boundless Bio equityholders owning about 3.7%.
Before closing, Boundless Bio may declare a cash dividend to its pre‑merger stockholders, currently expected to total roughly $44–$48 million, reflecting excess net cash. Serapha has already raised approximately $138 million in Series A preferred financing and secured an additional $92 million PIPE commitment, giving the combined company expected cash runway into the second half of 2029.
In connection with the merger, Boundless Bio will cut about 75% of its workforce, incurring one‑time charges of approximately $3.0–$5.0 million, and will wind down its BBI‑940 oncology program after early clinical data showed human exposure below preclinical expectations. CEO Zachary Hornby and several senior R&D leaders will depart, with Chief Legal Officer Jessica Oien becoming principal executive officer during the transition. All outstanding employee stock options have been fully vested and their exercise period extended, while underwater Boundless Bio options with exercise prices above $8.00 will be cancelled at closing.
Boundless Bio, Inc. held its annual stockholder meeting on June 15, 2026, where two proposals were approved. Stockholders elected James Christensen, Ph.D. and Jennifer Lew as Class II directors to serve until the 2029 annual meeting and until their successors are elected and qualified.
Christensen received 9,287,096 votes for and 512,585 votes withheld, while Lew received 9,271,084 votes for and 528,597 votes withheld; each had 5,757,105 broker non-votes. Stockholders also ratified KPMG LLP as the independent registered public accounting firm for the fiscal year ending December 31, 2026, with 15,376,973 votes for, 127,747 against and 52,066 abstentions.
Boundless Bio director Nancy Whiting received a grant of stock options for 32,000 shares of Common Stock at an exercise price of $1.40 per share. The options vest in substantially equal monthly installments over 12 months after June 15, 2026, or in full at the next annual stockholder meeting before June 15, 2027, if earlier, contingent on continued board service.
Boundless Bio director Jonathan E. Lim received a grant of stock options for 48,000 shares of common stock. The options have an exercise price of $1.40 per share and expire on June 14, 2036.
The option grant vests in substantially equal monthly installments over the 12 months following June 15, 2026, or earlier in full on the date of the next annual stockholder meeting if that meeting occurs before June 15, 2027. Vesting is conditioned on Lim’s continued service on the board of directors.
Boundless Bio director James Christensen received a grant of stock options, giving him the right to buy 32,000 shares of Common Stock. The options have an exercise price of $1.4000 per share and expire on June 14, 2036.
The award vests in substantially equal monthly installments over the 12 months following June 15, 2026, or earlier on the date of the next annual stockholder meeting if that occurs before June 15, 2027, as long as he continues serving on the board of directors.
Boundless Bio, Inc. director Jennifer Lew received a grant of stock options covering 32,000 shares of common stock. The options have an exercise price of $1.4000 per share and expire on June 14, 2036. They vest in substantially equal monthly installments over the 12 months following June 15, 2026, or in full on the date of the next annual stockholder meeting if it occurs before June 15, 2027, subject to her continued board service. This is a compensation-related award and does not involve any open-market buying or selling of shares.