Plan to Implement ADS Ratio Change

Renalytix plc

("Renalytix" or the "Company")

Renalytix Announces Plan to Implement ADS Ratio Change

LONDON and NEW YORK, 25 November 2025 - Renalytix plc (LSE: RENX) (OTCQB: RNLXY), a precision medicine diagnostics company, with kidneyintelX.dkd, the only FDA-approved and Medicare reimbursed prognostic test to support early-stage risk assessment in chronic kidney disease, announces plans to change the ratio of its American Depository Shares ("ADSs") to its ordinary shares from one (1) ADS, representing two (2) ordinary shares, to one (1) ADS representing fifty (50) ordinary shares (the "ADS Ratio"). The change in the ADS Ratio is expected to become effective on or about 12 December 2025 (the "Effective Date").

For the Company's ADS holders, the change in the ADS Ratio has the same effect as a one-for-twenty five reverse ADS split and will have no impact on an ADS holder's proportional equity interest in the Company. The change in the ADS Ratio is intended to further support the liquidity in the Company's ADSs, reduce the cost and expenses of the ADS program to the Company and its shareholders, and to provide future alternatives to regaining compliance with the U.S. listing exchanges' minimum bid price requirements. On the Effective Date, registered holders of the Company's ADSs held in certificated form will be required on a mandatory basis to surrender their certificated ADSs to Citibank, N.A., the depositary bank (the "Depositary"), for cancellation and will receive one (1) new ADS in exchange for every twenty five (25) existing ADSs surrendered. Holders of uncertificated ADSs in the Direct Registration System (DRS) and The Depository Trust Company (DTC) will have their ADSs automatically exchanged and need not take any action. The exchange of every twenty five (25) then-held (existing) ADSs for one (1) new ADS will occur automatically at the Effective Date, with the then-held ADSs being cancelled and new ADSs being issued by the Depositary. The Company's ADSs will continue to be traded on OTCQB under the ticker symbol "RNLXY."

No fractional new ADSs will be issued in connection with the change in the ADS Ratio. Instead, fractional entitlements to new ADSs will be aggregated and sold by the Depositary, and the net cash proceeds from the sale of the fractional ADS entitlements (after deduction of fees, taxes, and expenses) will be distributed to the applicable ADS holders by the Depositary.

As a result of the change in the ADS Ratio, the ADS trading price is expected to increase proportionally, although the Company can give no assurance that the ADS trading price after the change in the ADS Ratio will be proportionally equal to or greater than the previous ADS trading price prior to the change or that the change in the ADS Ratio will have any effect on the liquidity in the Company's ADSs.

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About Renalytix (www.renalytix.com)

Renalytix (LSE: RENX) (OTCQB: RNLXY) is an artificial intelligence-enabled in vitro diagnostics company, focused on optimizing clinical management of kidney disease to drive improved patient outcomes. Renalytix has received FDA approval and Medicare reimbursement for kidneyintelX.dkd which is now offered commercially in the United States.

Unrecognized and uncontrolled kidney disease remains one of the largest barriers to controlling cost and suffering in the United States and the United Kingdom's medical system, affecting over 14 million and 8 million people, respectively. After five years of development and clinical validation, kidneyintelX.dkd is the only FDA-approved and Medicare reimbursed prognostic tool capable of understanding a patient's risk with kidney disease early where treatment has maximal effect. kidneyintelX.dkd is now being deployed across large physician group practices and health systems in select regions of the United States.

The over 15,000 patients that have been tested by kidneyintelX.dkd have produced a substantial body of real-world performance data. In patient populations where kidneyintelX.dkd has been deployed, a demonstrated and significant increase in diagnosis, prognosis, and treatment rates have been recorded. kidneyintelX.dkd now has full reimbursement established by Medicare, the largest insurance payer in the United States, at $950 per reportable result. kidneyintelX.dkd is also recommended for use in the international chronic kidney disease clinical guidelines (KDIGO).

KidneyIntelX is based on technology developed by Mount Sinai faculty and licensed to Renalytix AI, Inc. Mount Sinai faculty members are co-founders and equity owners in the Company. In addition, the Icahn School of Medicine at Mount Sinai has equity ownership in Renalytix. For information about the kidneyintelX,dkd test, visit kidneyintelx.com.