Otelixizumab
Encyclopedia
Otelixizumab, also known as TRX4, is a monoclonal antibody, which is being developed for the treatment of type 1 diabetes and other autoimmune diseases. The antibody is being developed by Tolerx, Inc. in collaboration with GlaxoSmithKline
and is being manufactured by Abbott Laboratories
.
involved in normal cell signaling. More specifically, otelixizumab targets the epsilon chain of CD3
. Data suggest that the drug works by blocking the function of effector T cells, which mistakenly attack and destroy insulin-producing beta cells
while stimulating regulatory T cells, which are understood to protect against effector T cell damage, thus preserving the beta cells' normal ability to make insulin.
Proof of concept was established in a randomized, placebo-controlled Phase 2 study. These data demonstrated otelixizumab’s ability to preserve beta cell function, as measured by C-peptide
, in patients up to 18 months after dosing, as well as reduce the need for delivered insulin to maintain glucose control.
" status by the U.S. Food and Drug Administration.
. The heavy chains are humanized γ1 (gamma-1) chains from rats, making otelixizumab an immunoglobulin G1. The light chains are chimeric human/rat λ (lambda) chains.
GlaxoSmithKline
GlaxoSmithKline plc is a global pharmaceutical, biologics, vaccines and consumer healthcare company headquartered in London, United Kingdom...
and is being manufactured by Abbott Laboratories
Abbott Laboratories
Abbott Laboratories is an American-based global, diversified pharmaceuticals and health care products company. It has 90,000 employees and operates in over 130 countries. The company headquarters are in Abbott Park, North Chicago, Illinois. The company was founded by Chicago physician, Dr....
.
Mechanism of action
Otelixizumab is one of several investigational monoclonal antibodies that target CD3, a T lymphocyte receptorT cell receptor
The T cell receptor or TCR is a molecule found on the surface of T lymphocytes that is responsible for recognizing antigens bound to major histocompatibility complex molecules...
involved in normal cell signaling. More specifically, otelixizumab targets the epsilon chain of CD3
CD3E
CD3e molecule, epsilon also known as CD3E is a polypeptide which in humans is encoded by the CD3E gene which resides on chromosome 11.- Function :...
. Data suggest that the drug works by blocking the function of effector T cells, which mistakenly attack and destroy insulin-producing beta cells
B cell
B cells are lymphocytes that play a large role in the humoral immune response . The principal functions of B cells are to make antibodies against antigens, perform the role of antigen-presenting cells and eventually develop into memory B cells after activation by antigen interaction...
while stimulating regulatory T cells, which are understood to protect against effector T cell damage, thus preserving the beta cells' normal ability to make insulin.
Proof of concept was established in a randomized, placebo-controlled Phase 2 study. These data demonstrated otelixizumab’s ability to preserve beta cell function, as measured by C-peptide
C-peptide
C-peptide is a protein that is produced in the body along with insulin. First preproinsulin is secreted with an A-chain, C-peptide, a B-chain, and a signal sequence. The signal sequence is cut off, leaving proinsulin...
, in patients up to 18 months after dosing, as well as reduce the need for delivered insulin to maintain glucose control.
Clinical progress
The efficacy and safety of otelixizumab for the treatment of autoimmune type 1 diabetes is currently being studied in a pivotal Phase 3 study called DEFEND (Durable-response therapy Evaluation For Early or New-onset type 1 Diabetes). DEFEND is a randomized, placebo-controlled Phase 3 trial designed to enroll approximately 240 adult patients, age 18 to 45, with newly diagnosed autoimmune type 1 diabetes. DEFEND is being conducted at multiple centers in North America and Europe. The trial is designed to evaluate whether a single course of otelixizumab, administered not more than 90 days after the initial diagnosis, will reduce the amount of administered insulin required to control blood glucose levels by inhibiting the destruction of beta cells. The trial failed to show efficacy of the treatment.Orphan drug status
Otelixizumab has been granted "orphan drugOrphan drug
An orphan drug is a pharmaceutical agent that has been developed specifically to treat a rare medical condition, the condition itself being referred to as an orphan disease...
" status by the U.S. Food and Drug Administration.
Chemistry
As a monoclonal antibody, otelixizumab consists of two heavy chains and two light chainsImmunoglobulin light chain
]The immunoglobulin light chain is the small polypeptide subunit of an antibody .A typical antibody is composed of two immunoglobulin heavy chains and two Ig light chains.-In humans:...
. The heavy chains are humanized γ1 (gamma-1) chains from rats, making otelixizumab an immunoglobulin G1. The light chains are chimeric human/rat λ (lambda) chains.