Summit Therapeutics Launches $380 Million At-the-Market Equity Offering Program with J.P. Morgan Securities

Distribution Agreement Details and Operational Control

Effective July 23, 2026, Summit Therapeutics appointed J.P. Morgan Securities LLC as its exclusive sales agent under the new distribution agreement. The sales agent is authorized to sell shares of Summit's common stock at prevailing market prices, prices related to market prices, or negotiated prices based on market conditions and company preferences. J.P. Morgan will use commercially reasonable efforts consistent with its standard trading practices to execute sales following Summit's instructions, including any specified price, timing, or volume limits.

This agreement structure provides Summit with significant operational control over the capital raising process. The company can set specific parameters for each offering, such as minimum price thresholds, maximum daily or weekly volumes, and designated selling windows. Additionally, Summit can suspend solicitations and offers at any time without penalty or prior notice, a flexibility typical of ATM offerings that allow gradual capital access rather than a single fixed-price public offering.

Offering Size and Commission Terms

The agreement authorizes Summit to sell common stock totaling up to $380 million in aggregate offering price. This amount represents a maximum ceiling rather than a commitment to raise the full sum. Summit is under no obligation to sell any shares and may choose to raise less or none depending on business needs and market conditions.

J.P. Morgan Securities LLC will receive a commission of up to 3.0% of the gross sales price for each share sold. This commission is standard for ATM offerings and compensates the sales agent for facilitating transactions. The commission reduces the net proceeds Summit receives per share sold.

Execution Methods and Market Flexibility

Shares sold under the agreement may be executed through various methods and venues. Sales can occur as ordinary brokers' transactions on the Nasdaq Global Market, where Summit’s common stock trades under the symbol SMMT, or on other trading markets for the securities. This flexibility allows routing transactions to venues that offer optimal execution and pricing.

Besides open market sales, the agreement permits alternative execution methods such as transactions with market makers, block trades involving large share quantities, or negotiated transactions with qualified buyers. Block trades enable the sales agent to sell substantial share blocks to institutional investors, potentially securing better pricing when demand is strong. Negotiated transactions allow direct discussions on pricing and terms with sophisticated buyers, facilitating customized arrangements.

Registration Statement and Prospectus Compliance

The ATM offering is conducted pursuant to Summit’s effective Form S-3 registration statement filed with the SEC on June 9, 2026, which became automatically effective upon filing. Form S-3 streamlines securities registration for eligible companies meeting SEC criteria related to market capitalization and public float.

On July 23, 2026, Summit filed a prospectus supplement with the SEC alongside the distribution agreement. This supplement provides detailed information about the ATM offering, including company background, risk factors, use of proceeds, and other material disclosures required by federal securities laws. Together with the base prospectus in the Form S-3, it forms the complete offering document provided to investors before share purchases.

Strategic Capital Raising Flexibility

ATM programs offer biopharmaceutical companies like Summit strategic flexibility to access capital markets without committing to a fixed raise amount or timeline. Unlike traditional public offerings, ATM programs enable opportunistic share sales as market conditions warrant, which is beneficial for capital-intensive industries where funding needs evolve with clinical development and business priorities.

The $380 million authorization provides Summit with a significant capital resource to support operations, R&D, clinical trials, acquisitions, partnerships, and general corporate purposes. This equity capital access complements other financing strategies such as debt issuance and collaborations, offering optionality in managing the balance sheet and advancing the therapeutic pipeline.

Legal Counsel and Documentation

Baker & Hostetler LLP, counsel to Summit Therapeutics, issued a legal opinion affirming the validity of the shares issued under the distribution agreement. Filed as Exhibit 5.1, the opinion confirms that shares sold will be validly issued, fully paid, and non-assessable under Delaware law. Such opinions are standard in securities offerings, providing assurance regarding the legal status of the securities.

The full distribution agreement text, filed as Exhibit 1.1, details all terms, conditions, representations, warranties, and obligations of Summit and J.P. Morgan Securities LLC. This contract governs the relationship and procedures for the ATM offering, ensuring transparency and regulatory compliance.

No Obligation to Sell and Suspension Rights

Summit is under no obligation to sell any shares under the distribution agreement, distinguishing ATM offerings from traditional underwritten public offerings where share amounts are committed. The company retains full discretion over whether, when, and how many shares to sell.

Summit also reserves the right to suspend solicitations and offers at any time without penalty or advance notice. This right allows the company to pause sales due to unfavorable market conditions, material non-public information, or other business considerations, providing valuable flexibility during volatile periods.

Market Impact and Shareholder Considerations

The impact of ATM offerings on Summit’s share price and market dynamics depends on the volume and pace of share sales, overall market sentiment, and demand for the stock. Because shares are sold at prevailing market prices rather than fixed prices, this method can yield better pricing during strong demand periods but may result in lower proceeds when demand weakens.

Investors should be aware that ATM programs may cause dilution if shares are sold, affecting ownership percentages and earnings per share. Although Summit is not required to sell shares, the $380 million authorization represents potential future dilution, and shareholders should monitor announcements regarding actual sales activity.

Regulatory Classification and Offering Structure

The distribution agreement classifies sales as "at-the-market" offerings under Rule 415(a)(4) of the Securities Act of 1933, as amended. This classification signifies offerings conducted at prevailing market prices via ordinary trading mechanisms rather than fixed-price underwritten or negotiated transactions.

Summit's disclosure that sales may be executed as "ordinary brokers' transactions" on the Nasdaq Global Market underscores the commitment to standard trading infrastructure. This promotes market efficiency and transparency regarding pricing and volumes, ensuring compliance with regulatory requirements associated with Rule 415(a)(4).