Freeline to Present New Clinical Data for FLT180a in Hemophilia B at International Society on Thrombosis and Haemostasis Congress

The presentation will provide safety and initial efficacy data from the first cohort of the Phase 1/2 B-LIEVE trial, which aims to confirm the FLT180a dose and immune management regimen for the pivotal Phase 3 trial planned for 2023

LONDON, June 24, 2022 (GLOBE NEWSWIRE) — Freeline Therapeutics Holdings plc (Nasdaq: FRLN) today announced the upcoming presentation of new and important clinical data for its AAVS3-based gene therapy candidate FLT180a at the International Society on Thrombosis and Haemostasis (ISTH) Congress to be held in London, July 9-13, 2022.

The presentation will provide safety and initial efficacy data from the first cohort of the Phase 1/2 B-LIEVE trial, which aims to confirm the FLT180a dose and immune management regimen for the pivotal Phase 3 trial planned for 2023. The goal of treatment with FLT180a is to provide a functional cure for people with hemophilia B by delivering predictable and sustained normalization of coagulation Factor IX levels with a good safety profile.

The poster (PB0213) will be presented between 6:30pm-7:30pm BST on Sunday, July 10, 2022. The abstract has been published on the ISTH website:

Young G et al. Results from B-LIEVE, a Phase 1/2 Dose-Confirmation Study of FLT180a AAV Gene Therapy in Patients with Hemophilia B

The poster presentation will be available on the Investors section of Freeline’s website following presentation at the ISTH Congress.

About the B-LIEVE Dose-Confirmation Trial

B-LIEVE is a Phase 1/2 dose confirmation trial of FLT180a using a short course of prophylactic immune management with the goal of normalizing FIX levels in patients with severe and moderately severe hemophilia B. The starting dose of 7.7e11 vg/kg was selected based on the results of the Phase 1/2 B-AMAZE dose-finding trial and multiple modeling approaches. Freeline expects the B-LIEVE trial to finalize a dose for the pivotal Phase 3 trial intended to consistently enable predictable and sustained Factor IX (FIX) expression in the normal range for people with hemophilia B.

About FLT180a for People with Hemophilia B

Freeline’s FLT180a candidate uses a potent, rationally designed AAVS3 capsid containing an expression cassette encoding a gain of function Padua variant of human Factor IX (FIX). FLT180a has been studied in B-AMAZE, a Phase 1/2 dose-finding trial in patients with severe and moderately severe hemophilia B with the goal of normalizing FIX activity in patients with moderate and severe hemophilia B. Patients treated in B-AMAZE are being followed in a long-term follow-up study. A Phase 1/2 dose-confirmation trial of FLT180a called B-LIEVE to finalize a dose for a Phase 3 pivotal trial is in progress.

About Hemophilia B

Hemophilia B is a rare, debilitating, hereditary bleeding disorder caused by a defect in the coagulation Factor IX (FIX) gene. Hemophilia B is linked to the X chromosome and mainly affects boys and men; however, women who carry an affected copy of the coagulation factor gene may also experience symptoms. Hemophilia B is classified as mild, moderate or severe, depending on the level of FIX in the blood, and is diagnosed through blood tests. The 2020 Annual Global Survey by the World Federation of Hemophilia estimated that there are approximately 15,000 patients with hemophilia B in the United States, Europe and Japan. A meta-analysis using national registries in Australia, Canada, France, Italy, New Zealand and the UK estimated a prevalence in males of 3.8 in 100,000 or approximately 1 in 30,000.1

About Freeline Therapeutics

Freeline is a clinical-stage biotechnology company developing transformative adeno-associated virus (AAV) vector-mediated systemic gene therapies. The company is dedicated to improving patient lives through innovative, one-time treatments that may provide functional cures for inherited systemic debilitating diseases. Freeline uses its proprietary, rationally designed AAV vector, along with novel promoters and transgenes, to deliver a functional copy of a therapeutic gene into human liver cells, thereby expressing a persistent functional level of the missing or dysfunctional protein into the patient’s bloodstream. The company’s integrated gene therapy platform includes in-house capabilities in research, clinical development and commercialization. The company has clinical programs in hemophilia B, Fabry disease, and Gaucher disease Type 1. Freeline is headquartered in the UK and has operations in Germany and the U.S.

Forward-Looking Statements

This press release contains statements that constitute “forward looking statements” as that term is defined in the United States Private Securities Litigation Reform Act of 1995, including statements that express the opinions, expectations, beliefs, plans, objectives, assumptions or projections of Freeline Therapeutics Holdings plc (the “Company”) regarding future events or future results, in contrast with statements that reflect historical facts. In some cases, you can identify such forward-looking statements by terminology such as “anticipate,” “intend,” “believe,” “estimate,” “plan,” “seek,” “project” or “expect,” “may,” “will,” “would,” “could” or “should,” the negative of these terms or similar expressions. Forward-looking statements are based on management’s current beliefs and assumptions and on information currently available to the Company, and you should not place undue reliance on such statements. Forward-looking statements are subject to many risks and uncertainties. Such risks and uncertainties may cause the statements to be inaccurate and readers are cautioned not to place undue reliance on such statements. We cannot guarantee that any forward-looking statement will be realized. Should known or unknown risks or uncertainties materialize or should underlying assumptions prove inaccurate, actual results could vary materially from past results and those anticipated, estimated or projected. Investors are cautioned not to put undue reliance on forward-looking statements. A further list and description of risks, uncertainties and other matters can be found in the Company’s Annual Report on Form 20-F for the fiscal year ended December 31, 2021 and in subsequent reports on Form 6-K, in each case including in the sections thereof captioned “Cautionary Statement Regarding Forward-Looking Statements” and “Item 3.D. Risk factors.” Many of these risks are outside of the Company’s control and could cause its actual results to differ materially from those it thought would occur. The forward-looking statements included in this press release are made only as of the date hereof. The Company does not undertake, and specifically declines, any obligation to update any such statements or to publicly announce the results of any revisions to any such statements to reflect future events or developments, except as required by law. For further information, please reference the Company’s reports and documents filed with the U.S. Securities and Exchange Commission (the “SEC”). You may review these documents by visiting EDGAR on the SEC website at

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1 Iorio A et al. Annals of Internal Medicine 2019;171(8):540-7