SERA PROGNOSTICS, INC.

Strategic Prioritization

As part of our transition from a clinical-stage company to a commercial organization, we recently completed a comprehensive business review to reallocate investment from research and development toward our reimbursement-focused commercialization of PreTRM and to right size our operating expenses. As a result, on May 6, 2026, we adopted operational changes to concentrate resources on the continued, disciplined commercialization of the PreTRM test by prioritizing resources toward payer engagement, market access, and clinical adoption, while reducing operating expenses in areas that are non-core to these commercialization activities. As part of these changes, we reduced our workforce by 14 full-time employees, or approximately 18% of our workforce. These reductions included Paul Kearney, Chief Data Officer, and Robert Harrison, Chief Information Officer, whose responsibilities will transition to our Director of IT and other functions within the organization. We estimate we will incur approximately $1.3 million in costs related to severance pay and other termination benefits, the majority of which will be incurred in the second and third quarters of 2026. As part of this strategic prioritization, we have initiated additional ongoing cost savings from other personnel-related expenses and pipeline alignment. As a result, we anticipate meaningful cost savings of approximately $9.6 million in 2027, with decreased cash expenses of approximately 35% and 25% in research and development and general and administrative costs, respectively, to enable continued prudent investment in commercial activity. With this new cost structure, we expect that our existing cash and cash equivalents will be sufficient to fund our operating expenses and capital expenditure requirements through 2029.

Separation with Paul Kearney as Chief Data Officer

Effective as of July 1, 2026 (the “Effective Date”), Paul Kearney will separate from Sera as our Chief Data Officer pursuant to the strategic prioritization. As a condition to Sera providing Dr. Kearney the severance benefits specified in his amended and restated executive employment agreement, dated March 13, 2026, the parties are expected to enter into a separation agreement including the required release and waiver. These severance benefits are as follows: (1) severance as a continuation of payments in an amount equal to Dr. Kearney’s current annual base salary for a nine-month period, which will total $333,617, less all required taxes and employment-related deductions, payable as continued salary in accordance with our regular payroll dates following the revocation period, (2) continued health insurance coverage for nine months, and (3) with respect to equity awards granted prior to January 1, 2026, 37.5% of the outstanding unvested shares of such awards will vest upon his separation.

Insider Trading Arrangements and Policies:

During the quarter ended March 31, 2026, none of our executive officers (as defined in Section 16 of the Exchange Act) and directors adopted orterminated any contract, instruction, or written plan for the purchase or sale of our securities that was intended to satisfy the affirmative defense of Rule 10b5-1(c) or any “non-Rule 10b5-1 trading arrangement,” as defined in Item 408(a) of Regulation S-K. Certain of our Section 16 officers may participate in our 2021 ESPP that has been designed to comply with Rule 10b5-1(c).