• Itolizumab in combination with systemic corticosteroids was associated with high rates of overall clinical response
• Response at Day 29 was associated with improved progression-free survival through 1 year
• Itolizumab is being evaluated in pivotal Phase 3 EQUATOR study in first-line acute graft-versus-host disease

LA JOLLA, Calif. / Apr 24, 2023 / Business Wire / Equillium, Inc. (Nasdaq: EQ), a clinical-stage biotechnology company leveraging a deep understanding of immunobiology to develop novel therapeutics to treat severe autoimmune and inflammatory disorders with high unmet medical need, today announced that an ePoster presentation highlighting data from the EQUATE study in acute graft-versus-host disease (aGVHD) was given yesterday at the 49th Annual Meeting of the European Society for Blood and Marrow Transplantation.

The presentation, given by Dr. Corey Cutler, associate professor of medicine, Dana Farber Cancer Institute, Harvard Medical School, highlights positive final study results, including long-term follow-up data for up to one year, from EQUATE (NCT03763318), a Phase 1b study of itolizumab in combination with corticosteroids (CS) to treat subjects with newly diagnosed severe aGVHD. The data demonstrate promising outcomes in subjects with severe aGVHD. Equillium has since initiated EQUATOR (NCT05263999), a pivotal Phase 3 study of itolizumab as a potential initial therapy for aGVHD in combination with CS.

“The full data set from the EQUATE study suggests that itolizumab has potential clinical value for the treatment of aGVHD,” said Dr. Cutler. “There are no drugs approved in the first-line setting of this potentially lethal condition, so I am encouraged to see rapid and durable responses demonstrating high progression-free survival through one year, as well as responders to itolizumab treatment having a clinically meaningful reduction in the use of corticosteroids of ninety-nine percent at six months.”

Title: Final Safety and Efficacy Results from EQUATE, an Open-Label Study Evaluating Itolizumab, a Novel Targeted anti-CD6 Therapy, in Newly Diagnosed Acute Graft-Versus-Host Disease
Presenting Author: Dr. Corey Cutler
Poster Number: P322

Key Highlights, Summary and Conclusions from Presentation:

• Itolizumab treatment in combination with systemic corticosteroids was associated with rapid and durable high rates of overall clinical response​
• Response at Day 29 was associated with improved progression-free survival through 1 year​
• Itolizumab was safe and well tolerated in severe aGVHD patients
• Itolizumab offers a favorable benefit-risk profile that supports evaluation in the pivotal Phase 3 study (EQUATOR NCT05263999), which has been initiated for the first-line treatment of aGVHD

The oral presentation is available on the Presentations page of Equillium’s website.

About Graft-Versus-Host Disease (GVHD)

GVHD is a multisystem disorder that is a common complication of allogeneic hematopoietic stem cell transplants (allo-HSCT) caused by the transplanted immune system recognizing and attacking the recipient’s body. Symptoms of GVHD include rash, itching, skin discoloration, nausea, vomiting, diarrhea, and jaundice, as well as eye dryness and irritation.

GVHD is the leading cause of non-relapse mortality in cancer patients receiving allo-HSCT, and its risk limits the number and type of patients receiving HSCT. GVHD results in high morbidity and mortality, with five-year survival of approximately 53% in patients who respond to steroid treatment and mortality as high as 95% in patients who do not respond to steroids. There are no approved treatments for first-line aGVHD. Published literature (MacMillan et al., 2015) describes background response rates to high-dose steroid administration in severe high-risk patients as 43% overall response and 27% complete response.

About the EQUATE Study

The EQUATE study was a Phase 1b trial to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics and clinical activity of itolizumab for first-line treatment in patients who present with aGVHD (NCT03763318). The Phase 1b part of the trial was an open-label dose escalation study in adult patients who present with high-risk acute graft-versus-host disease (aGVHD) and typically respond poorly to steroids. The Phase 1b data informed the selection of the dose being used in the EQUATOR pivotal Phase 3 study.

About Itolizumab

Itolizumab is a clinical-stage, first-in-class anti-CD6 monoclonal antibody that selectively targets the CD6-ALCAM signaling pathway to selectively downregulate pathogenic T effector cells while preserving T regulatory cells critical for maintaining a balanced immune response. This pathway plays a central role in modulating the activity and trafficking of T cells that drive a number of immuno-inflammatory diseases.

About Equillium

Equillium is a clinical-stage biotechnology company leveraging a deep understanding of immunobiology to develop novel therapeutics to treat severe autoimmune and inflammatory disorders with high unmet medical need. The company’s pipeline consists of the following novel first-in-class immunomodulatory assets targeting immuno-inflammatory pathways. EQ101: a tri-specific cytokine inhibitor that selectively targets IL-2, IL-9, and IL-15; currently under evaluation in a Phase 2 proof-of-concept clinical study of patients with alopecia areata. EQ102: a bi-specific cytokine inhibitor that selectively targets IL-15 and IL-21; currently under evaluation in a Phase 1 first-in-human clinical study to include healthy volunteers and celiac disease patients. Itolizumab: a monoclonal antibody that targets the CD6-ALCAM signaling pathway which plays a central role in the modulation of effector T cells; currently under evaluation in a Phase 3 clinical study of patients with acute graft-versus-host disease (aGVHD) and a Phase 1b clinical study of patients with lupus/lupus nephritis. Equillium acquired rights to itolizumab through an exclusive partnership with Biocon Limited and has entered a strategic partnership with Ono Pharmaceutical Co., Ltd. for the development and commercialization of itolizumab under an option and asset purchase agreement.

For more information, visit www.equilliumbio.com.

Forward Looking Statements

Statements contained in this press release regarding matters that are not historical facts are "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements may be identified by the use of words such as "anticipate", "believe", “could”, “continue”, "expect", "estimate", “may”, "plan", "outlook", “future” and "project" and other similar expressions that predict or indicate future events or trends or that are not statements of historical matters. Because such statements are subject to risks and uncertainties, many of which are outside of Equillium’s control, actual results may differ materially from those expressed or implied by such forward-looking statements. Such statements include, but are not limited to statements regarding the benefit of treating patients with aGVHD with itolizumab and Equillium’s plans for developing itolizumab. Risks that contribute to the uncertain nature of the forward-looking statements include: Equillium’s ability to execute its plans and strategies; risks related to performing clinical studies; whether the results from clinical studies will validate and support the safety and efficacy of Equillium’s product candidates; and risks related to Ono’s financial condition, willingness to continue to fund the development of itolizumab, and decision to exercise, if ever, its option to purchase itolizumab or terminate the asset purchase agreement. These and other risks and uncertainties are described more fully under the caption "Risk Factors" and elsewhere in Equillium's filings and reports, which may be accessed for free by visiting the Securities and Exchange Commission’s website at www.sec.gov and on Equillium’s website under the heading “Investors.” Investors should take such risks into account and should not rely on forward-looking statements when making investment decisions . All forward-looking statements contained in this press release speak only as of the date on which they were made. Equillium undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made, except as required by law.