IGM is the global leader in the development of therapeutic IgM antibodies.  Since 2010, we have focused exclusively on the research, development and production of IgM and IgA antibodies.

Our breakthroughs in manufacturing and protein engineering have enabled the development of therapeutic IgM antibodies and have created a broad intellectual property portfolio covering J chain containing antibodies (IgM and IgA).

Naturally, humans have five classes of antibodies (IgA, IgD, IgE, IgG and IgM) as components of their immune system, however, all of the therapeutic antibodies used currently to treat patients are IgG based.


As seen in the diagrams above, IgM antibodies provide 10 binding units (shaded in yellow above) to their immune system target, as opposed to 2 binding units for an IgG antibody. IgM is the only class of antibodies which has 10 binding units and the corresponding level of binding strength (avidity) to cell surface targets. IgA antibodies can naturally contain either 2 or 4 binding units, but IgG and all other antibody classes naturally contain only 2 binding units.

The 10 binding units of the IgM antibody  results in far greater binding power (avidity) to a cell surface target as compared with an IgG antibody with 2 binding units.

Advantages of IgM Antibodies

The inherent biological advantages of the IgM antibodies as compared to comparable IgG antibodies include:

  • Stronger binding to low expression cell surface targets
  • Stronger binding to difficult cell surface targets, such as carbohydrates and highly glycosylated proteins
  • Greater ability to cross-link cell surface receptors for increased cellular signaling
  • Stronger complement dependent cytoxicity (CDC)

Stronger binding to a difficult (highly glycosylated) cell surface tumor target of two IgM antibodies as compared to two comparable IgG antibodies.


Stronger IgM antibody binding to a rare cell surface oncology target as compared to a comparable IgG antibody.


Greatly improved IgM antibody cross-linking (binding groups of cell surface targets closely together) of an apoptotic oncology cell surface target, as compared to a comparable IgG antibody; resulting in much stronger intracellular signaling and increased apoptosis (cell death).

Intellectual Property

IGM has built a broad intellectual property portfolio with respect to IgM and IgA antibodies including granted patents, patent applications and trade secrets.


Through our focused efforts since 2010, we have developed skill, knowledge, trade secrets and other intellectual property that is essential to the successful protein engineering, expression, purification and formulation of J chain containing antibodies (IgM and IgA).

We have successfully manufactured an IgM antibody at scale under GMP conditions, and we have developed efficient purification and stable formulations of IgM antibodies.

Vialed drug from our first GMP manufacturing run has demonstrated stability at four years, and continued stability testing is on-going.