Celyad Oncology

Mont-Saint-Guibert, Belgium – Celyad Oncology SA (Euronext & Nasdaq: CYAD), a clinical-stage biotechnology company focused on the discovery and development of chimeric antigen receptor T cell (CAR T) therapies for cancer, today announced it will host a Research & Development webinar on Tuesday, July 20^th at 11:30 a.m. EDT.

Members of the Celyad Oncology leadership team will provide an overview of the recent advances in the R&D pipeline including insights into new preclinical allogeneic CAR T assets using shRNA technology and updates on key clinical programs. Updates will include information around the shRNA-based allogeneic candidate CYAD-211 for relapsed/refractory multiple myeloma and the industry-leading allogeneic candidate CYAD-101 for metastatic colorectal cancer in advance of the launch of the KEYNOTE-B79 clinical trial. 

The live webcast of the presentation can be accessed by visiting the “Events” section of the Celyad Oncology website.  Please connect to the webcast several minutes prior to the start of the event to ensure the connection. To register for the live webcast, click here.  After the conclusion of the event, a replay of the webcast will also be available on the Celyad Oncology website.

• Treatment with CYAD-211 generally well-tolerated at first two dose levels, with no evidence of Graft-versus-Host Disease observed
• Two partial responses observed among five evaluable patients
• Cell engraftment of CYAD-211 observed in all patients from dose level 2, with evidence of CAR T cells in all patients enrolled in first two dose cohorts
• Additional clinical data from the dose escalation trial are expected during second half 2021
• Management to host conference call later today, June 11, at 2 p.m. CET / 8 a.m. ET

Mont-Saint-Guibert, Belgium – Celyad Oncology SA (Euronext & Nasdaq: CYAD), a clinical-stage biotechnology company focused on the discovery and development of chimeric antigen receptor T cell (CAR T) therapies for cancer, today announced preliminary data from the Phase 1 IMMUNICY-1 trial of CYAD-211 for the treatment of relapsed/refractory multiple myeloma (r/r MM) patients were presented at the European Hematology Association (EHA) 2021 Virtual Congress.

Filippo Petti, Chief Executive Officer of Celyad Oncology, commented, “We believe the initial data presented today are meaningful beyond the demonstrated clinical activity of CYAD-211. This is the first clinical trial evaluating the potential of shRNA as an allogeneic technology to underpin off-the-shelf CAR T candidates for the treatment of cancer, and today’s data continue to demonstrate the potential value of non-gene edited technology to generate allogeneic CAR T cells. We are extremely encouraged by the cell kinetic, clinical activity and tolerability data for CYAD-211. As we work to establish shRNA as a platform for developing allogeneic CAR T therapies, these early data from the IMMUNICY-1 trial are key. In addition, we believe our future ability to employ multiple shRNAs in our CAR T candidates while leveraging our streamlined All-in-One Vector approach could be fundamental to the allogeneic CAR T landscape.”

Dr. Sébastien Anguille, IMMUNICY-1 trial investigator and professor in the Division of Hematology of the Antwerp University Hospital said, “Even with great strides made in recent years, multiple myeloma remains largely incurable, creating a need for new therapeutic options. Unfortunately, most patients eventually relapse and we observe shorter duration and depth of responses to treatments over time. We are pleased with the encouraging initial data from the IMMUNICY-1 trial and we’re eager to move forward with higher doses and continue to evaluate CYAD-211 in treating myeloma patients.”

CYAD-211 and IMMUNICY-1 Phase 1 Trial Update

Background:

• CYAD-211 is an allogeneic CAR T candidate engineered to co-express a BCMA targeting chimeric antigen receptor and a single short hairpin RNA (shRNA), which interferes with the expression of the CD3ζ component of the T cell receptor complex.
• IMMUNICY-1 is a first-in-human, open-label, dose-escalation Phase 1 trial to determine the recommended dose of CYAD-211 in patients with r/r MM following preconditioning with cyclophosphamide (300 mg/m²) and fludarabine (30 mg/m²) given three consecutive days.
• The trial is designed to evaluate proof-of-concept that shRNA-mediated knockdown of the CD3ζ can generate allogeneic CAR T cells.

Safety and tolerability data:

Of the six patients dosed at the first two dose levels (30×10⁶ and 100×10⁶ cells per infusion):

• No dose limiting toxicity (DLT), Graft-versus Host disease (GvHD) or CAR T-cell-related encephalopathy syndrome (CRES) were observed in the first two dose cohorts.
• One cytokine release syndrome (CRS) Grade 1 (fever) requiring hospitalization occurred 10 days post CYAD-211 administration in patient 1 (dose level 1) who achieved a partial response (PR).
• One patient experienced an anemia adverse event (Grade 3) and neutropenia (Grade 4) possibly related to CYAD-211.

Clinical activity:

Of the five evaluable patients at the first two dose levels (30×10⁶ and 100×10⁶ cells per infusion):

• Two patients achieved a PR. Both patients were ‘triple-therapy exposed’ (previously treated with an immunomodulator (IMiD), a proteasome inhibitor and an anti-CD38 antibody).
• The three additional patients had stable disease (SD).

Cell kinetics:

• CYAD-211 cells were detected by PCR-based methods in all six patients from dose cohorts 1 and 2.
• Cell engraftment was seen in all three patients at dose level 2 at a similar magnitude. In addition, preliminary data suggest that all patients in dose level 2 showed deep lymphodepletion. Across dose level 1, the depth of lymphodepletion appears to correlate with the degree of observed systemic CAR T engraftment.

Next steps:

• Enrollment in dose cohort 3 (300×10⁶ cells per infusion) is ongoing.
• Additional clinical data from the dose escalation trial are expected during second half 2021.
• shRNA technology platform to be highlighted at upcoming virtual R&D Day in Q3 2021.

Conference Call and Webcast Details

Celyad Oncology will host a conference call to discuss the update from EHA on Friday, June 11, 2021 at 2 p.m. CET / 8 a.m. ET. The conference call can be accessed through the following numbers:

United States: #1 877-407-9208

International: #1 201-493-6784

The conference call will be webcast live and can be accessed here. The event will also be archived and available on the “Events ” section of the company’s website. Please visit the website several minutes prior to the start of the broadcast to ensure adequate time for registration to the webcast.

Mont-Saint-Guibert, Belgium – Celyad Oncology SA (Euronext & Nasdaq: CYAD), a clinical-stage biotechnology company focused on the discovery and development of chimeric antigen receptor T cell (CAR T) therapies for cancer, announced on May 31, 2021 a

capital increase of 182,000 new shares of the Company through its Open Market Sale Agreement^SM with Jefferies LLC. As a result, the Company’s share capital is increased to 52,844,560.33 EUR and is represented by 15,187,156 shares.

This information is published in accordance with Article 15 of the Belgian Law of 2 May 2007 on the disclosure of major participations in issuers whose shares are admitted to trading on a regulated market and regarding miscellaneous provisions.

Figures – Modified on 31 May 2021 following the Capital Increase:

Total amount of share capital (EUR)	52,844,560.33
Total Number of shares with single voting rights	12,819,131
Total Number of shares with double voting rights	2,368,025
Total Number of Shares	15,187,156
Total of voting rights	17,555,181
Total number of attributed warrants	1,927,756
Total number of shares with voting rights that could be created following the exercise of the attributed warrants	1,927,756
Total number of diluted shares (Outstanding shares + Warrants)	17,114,912
Total number of diluted shares with voting rights	19,482,937

Contact person for regulated information (financial, transparency)

By law, any transparency declaration must be sent to our Company by email to the attention of Filippo Petti, Chief Executive Officer (CEO): investors@celyad.com.

Further questions about the content of this release can be sent to investors@celyad.com.