Summit Therapeutics (SMMT) SEC Filings, Apr-Jun 2026

Summit Therapeutics Inc. has withdrawn its previously announced proposed underwritten public offering of securities, effective June 10, 2026, citing market conditions. Because the offering has been terminated, no securities will be sold under that proposed transaction. The update is provided as a Regulation FD disclosure and is not treated as a filed report for liability purposes under Section 18 of the Exchange Act.

Summit Therapeutics Inc. intends to offer $500.0 million of common stock in a registered primary offering, with an at‑the‑market program complement and a 30‑day underwriter option for up to $75,000,000 of additional shares.

The preliminary prospectus supplement states an assumed public offering price of $14.11 per share, implying 35,435,861 shares offered at that price. The company reported 776,017,474 shares outstanding as of March 31, 2026, net tangible book value of $544.0 million (or $0.70 per share), and approximately 118.9 million shares subject to outstanding options or RSUs as of that date. Summit says net proceeds will fund continued development of ivonescimab and for working capital, and notes substantial doubt about its ability to continue as a going concern absent additional funding.

Summit Therapeutics Inc. filed a shelf registration on Form S-3 to permit offers and sales of common stock, preferred stock, debt securities, depositary shares, warrants, subscription rights and units from time to time after the effective date.

The prospectus states the company’s common stock last traded at $14.11 per share on June 8, 2026, and discloses a going concern warning: management concluded there is substantial doubt about the company’s ability to continue as a going concern absent additional funding for the next twelve months. The prospectus reserves no specific aggregate offering amount and says net proceeds will be used for general corporate purposes, with specific terms to be provided in prospectus supplements.

Summit Therapeutics Inc. director and Co‑CEO Robert W. Duggan reported an indirect open‑market purchase of 100,000 shares of Common Stock at $14.60 per share. The transaction was made by the Mahkam Zanganeh Revocable Trust, with his spouse as trustee, bringing that trust’s reported holdings to 25,824,474 shares.

The filing also lists additional positions associated with Duggan, including 570,073,879 shares held directly, 10,199,776 shares held by the Shaun Zanganeh Irrevocable Trust, 31,000 shares held by his spouse, and 76,680 shares held by an immediate family member of his spouse. A footnote states he disclaims beneficial ownership of these securities except to the extent of any pecuniary interest.

Summit Therapeutics Inc. Co-Chief Executive Officer Mahkam Zanganeh, acting through the Mahkam Zanganeh Revocable Trust where she serves as trustee, bought 100,000 shares of common stock in an open-market purchase at $14.60 per share.

Following this transaction, that revocable trust held 25,824,474 shares of Summit Therapeutics common stock. Additional holdings reported include 31,000 shares held directly, 10,199,776 shares held by the Shaun Zanganeh Irrevocable Trust with her as trustee, 570,073,879 shares held by her spouse, and 76,680 shares held by an immediate family member. She disclaims beneficial ownership of these securities beyond any pecuniary interest.

Summit Therapeutics Inc. director and executive officer Manmeet Singh Soni, who serves as COO and CFO, reported open-market purchases of the company’s common stock. On June 4, 2026, he bought 25,000 shares at $14.43 and another 25,000 shares at $14.46.

These transactions total 50,000 shares of Summit Therapeutics common stock acquired in the open market, leaving him with a direct ownership stake of more than three million shares.

Summit Therapeutics Inc. stated that on June 2, 2026, its Audit Committee and all independent directors approved one or more Company affiliates to purchase shares of its common stock through the Company’s previously disclosed at-the-market offering with JP Morgan Securities LLC as Sales Agent.

The Company also noted that Co-CEO and Chairman Robert Duggan, Co-CEO and President Dr. Mahkam Zanganeh, and COO/CFO Manmeet Soni have indicated they are likely to purchase shares under this at-the-market program in the near term. These executives have not specified how many shares they may buy and have made no binding commitments. Any purchases would occur at the prevailing market bid price or better.

Summit Therapeutics reported new clinical data for its investigational bispecific antibody ivonescimab in metastatic colorectal cancer (mCRC) and non-small cell lung cancer (NSCLC), highlighted at the 2026 ASCO meeting. In the global Phase II AK112-206 study in first-line unresectable mCRC, ivonescimab plus mFOLFOX6 chemotherapy achieved an objective response rate of 70.8% and a disease control rate of 100.0% in evaluable patients, with a landmark 9‑month progression-free survival rate of 76.1% at the 20 mg/kg dose and an overall acceptable, manageable safety profile.

Separately, Akeso’s China-based Phase III HARMONi-6 trial in first-line advanced squamous NSCLC showed ivonescimab plus platinum chemotherapy reduced the risk of death by 34% versus tislelizumab plus chemotherapy, with an overall survival hazard ratio of 0.66. Median overall survival was 27.89 months for ivonescimab versus 23.69 months for tislelizumab, and 24‑month overall survival rates were 64.7% versus 48.6%, respectively, with a safety profile broadly consistent with prior ivonescimab studies. Ivonescimab is already approved in China but remains investigational in Summit’s territories, where a separate Biologics License Application in NSCLC has been accepted with a PDUFA goal date of November 14, 2026.

Summit Therapeutics reported a sharply higher net loss and raised going concern doubts in its latest quarter. For the three months ended March 31, 2026, the company recorded a net loss of $189.4 million versus $62.9 million a year earlier, driven by intensive development spending on its lead cancer drug ivonescimab and a large increase in stock-based compensation.

Research and development expenses rose to $132.6 million, while general and administrative costs climbed to $62.6 million. Summit held $106.5 million in cash and cash equivalents and $492.2 million in short-term investments, which it states are insufficient to fund planned operations for at least one year, creating substantial doubt about its ability to continue as a going concern. The FDA has accepted the Biologics License Application for ivonescimab in EGFR-mutated lung cancer, with a Prescription Drug User Fee Act action date of November 14, 2026, but has indicated that a statistically significant overall survival benefit is necessary for potential approval.