Solid Tumor Analysis for HLA Loss of Heterozygosity (LOH) and Apheresis for CAR T- Cell Manufacturing

Background:

Human Leukocyte Antigen (HLA) is a protein on the outside of cells that allows the immune

system to recognize it's own cells as normal and leave them alone or respond if infected

with a virus or bacteria, or a tumor cell. HLA might not be expressed normally on cancer

cells. This may be why cancer can grow undetected by the immune system and is referred to

as a tumor escape mechanism. Tumor escape can occur for many reasons, but one reason is

Loss of Heterozygosity (LOH). LOH is the loss of one of the genes that encodes HLA

protein. A2 Biotherapeutics, Inc. (A2 Bio) is developing therapies to recognize, target,

and kill cancer cells that do not express HLA normally, and minimize any damage to normal

cells that express normal HLA.

Once participants are identified as having LOH on their tumors, apheresis, a procedure to

separate and collect white blood cells will be performed. It is the first required step

in manufacturing CAR T-cell therapy. The collected T cells will be stored for patients

that are likely to benefit from CAR T-cell therapy during their disease care.

Study Design:

Approximately 1000 participants will be screened for part 1 of the study, including HLA

typing, approximately 500 participants will have NGS testing on their tumor samples and

be followed for up to 2 years on the study, and up to 200 participants will be screened

for part 2 of the study and enrolled if eligible and apheresed and be followed for up to

2 years on the study.

Participants will be screened (Part 1) for HLA type, and based on results, participants

will have archived tumor tissue tested by next generation sequencing (NGS) and be

followed for up to 2 years. Based on the tumor NGS results, participants will be

apheresed (Part 2) for Peripheral Blood Mononuclear Cell (PBMC) collection to store their

T cells for a future interventional study upon relapse.

Each participant will proceed through the following study periods:

- Screening (Part 1 and 2)

- Enrollment (Apheresis)

- Post Apheresis safety follow-up (Day 7)

- Two-year long term follow-up