Talaris Therapeutics Presents High-Resolution Analysis of HLA Mismatching in Phase 2 Trial in Living Donor Kidney Transplant

Analysis confirms FCR001 induced durable tolerance in highly mismatched related and unrelated recipients

BOSTON and LOUISVILLE, Ky., Dec. 14, 2021 (GLOBE NEWSWIRE) — Talaris Therapeutics, Inc., (Nasdaq: TALS), a late-clinical stage cell therapy company, today presented a new analysis of HLA mismatching between donors and recipients participating in the Company’s Phase 2 trial in living donor kidney transplant (LDKT). High-resolution allele typing at six loci found that FCR001 induced durable immune tolerance in highly mismatched related and unrelated recipients. The findings were shared in an oral presentation by Joseph R. Leventhal, M.D., Ph.D., Fowler McCormick Professor of Surgery at Northwestern University Feinberg School of Medicine and principal investigator for the Phase 2 study, at the American Society of Hematology (ASH) Annual Meeting.

The new analysis is based on DNA samples collected in Talaris’ Phase 2 trial of FCR001 in living donor kidney transplant recipients. The focus of the analysis was to evaluate the degree of donor/recipient HLA mismatching using high-resolution allele typing at HLA-A, -B, -C, -DRB1, -DQB1 and -DPB1, and to understand its correlation with the ability to establish durable chimerism in this patient sample.

Samples from 29 of the 37 donor/recipient pairs were evaluated across all 12 of the relevant HLA alleles; three other donor/recipient pairs were evaluated across 10 alleles as the samples did not have sufficient DNA to test for locus DPB1. In the former group, 21 of 29 donor/recipient pairs had 6/12 or more mismatching; in the latter group, two of the three pairs had 5/10 or more mismatching. Despite this high degree of mismatch, durable chimerism induced by FCR001 allowed for full withdrawal of immunosuppression (IS) in 25 of these 32 subjects, with time off IS ranging from 3.5 to 11 years. Twelve of these 25 pairs were unrelated with ≥ 8 HLA mismatches, and the majority of treated patients showed >95% donor whole blood/T cell chimerism. As previously reported, there was limited incidence of GvHD, being two cases, both in the setting of a female donor to unrelated male recipient. An exclusion criterion for this donor-recipient pairing was added to the Phase 2 trial.

“We’re pleased to share this new, more detailed examination of the HLA mismatching among patients in our Phase 2 trial, indicating that FCR001 induced durable immune tolerance across very high levels of mismatch,” said Nancy Krieger, M.D., Chief Medical Officer of Talaris. “These insights are highly valuable as we progress our ongoing Phase 3 registrational study in LDKT, FREEDOM-1, and as we continue to expand the applications of Facilitated Allo-HSCT Therapy to other areas of high patient need.”

About Talaris Therapeutics
Talaris Therapeutics, Inc. is a late-clinical stage biopharmaceutical company developing investigational, one-time, allogeneic cell therapies with the potential to transform the standard of care in solid organ transplantation, certain severe autoimmune diseases, and certain severe non-malignant blood, immune and metabolic disorders. Talaris maintains corporate offices in Boston, MA, its cell processing facility in Louisville, KY, and additional research operations in Houston, TX.

Cautionary Note Regarding Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, implied and express statements regarding Talaris Therapeutics, Inc.’s (“Talaris,” the “Company,” “we,” or “our”) strategy, business plans and focus; the progress and timing of the preclinical and clinical development of Talaris’ programs, including FCR001 and the continued expansion of applications of Facilitated Allo-HSCT Therapy to other areas of high patient need. The words “may,” “might,” “will,” “could,” “would,” “should,” “expect,” “plan,” “anticipate,” “intend,” “believe,” “expect,” “estimate,” “seek,” “predict,” “future,” “project,” “potential,” “continue,” “target” or the negative of these terms and similar words or expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words.

Any forward-looking statements in this press release are based on management’s current expectations and beliefs and are subject to a number of risks, uncertainties and important factors that may cause actual events or results to differ materially from those expressed or implied by any forward-looking statements contained in this press release, including, without limitation, risks associated with: the timing and anticipated timing and results of its clinical trials; the risk that the results of Talaris’ clinical trials may not be predictive of future results in connection with future clinical trials; the Company’s ability to successfully demonstrate the safety and efficacy of its drug candidates. These and other risks and uncertainties are described in greater detail in the section entitled “Risk Factors” in the Company’s Quarterly Report on Form 10-Q for the quarter ended September 30, 2021, as well as any subsequent filings with the Securities and Exchange Commission. In addition, any forward-looking statements represent Talaris’ views only as of today and should not be relied upon as representing our views as of any subsequent date. Talaris explicitly disclaims any obligation to update any forward-looking statements. No representations or warranties (expressed or implied) are made about the accuracy of any such forward-looking statements.

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