Thema Keyhole limpet hemocyanin (KLH)

biosyn’s CEO explains how the company’s keyhole limpet hemocyanin helps fight recurrences in superficial bladder cancer

Megathura crenulata

In the early 1990s, the team of researchers around Dr. Thomas Stiefel, CEO of the pharmaceutical company biosyn, discovered that a unique sea creature living in the cold waters off Southern California’s Pacific coastline can provide a substance for use in cancer therapy. Keyhole limpet hemocyanin (KLH), an immunostimulating glycoprotein, is obtained by a non-lethal method from the hemolymph of the keyhole limpet (Megathura crenulata).


Mechanism for stimulating anti-tumor immune responses: How Keyhole Limpet Hemocyanin (KLH) antibodies detect and destroy bladder cancer cells

Numerous oligosaccharides are attached to the surface of the KLH molecule and account for about 4% of its molecular mass. With their intricate topology, these oligosaccharides contribute to KLH’s strong immunogenicity. Although not completely elucidated, different mechanisms of action are at play: non-specific stimulation of the immune system, stimulation of cytotoxic T cells and induction of anti-tumoral antibodies. KLH antibodies can bind to the Thomsen-Friedenreich antigens associated with cancer progression and metastasis on bladder carcinoma cells. The reaction of KLH antibody with Thomsen-Friedenreich antigen leads to phagocytosis and dissolution of the tumor cell. Immunocyanin, the main ingredient in IMMUCOTHEL® for the recurrence prevention of superficial urinary bladder carcinoma, is derived from KLH.


German know-how. American ingenuity. Good Manufacturing Practice for global hemocyanin products thrives in California.

Since its founding in Carlsbad, California in 1995, biosyn Corporation has driven the development, manufacturing and marketing of hemocyanin and immunocyanin products forward. With German know-how, American ingenuity and the help of a California resident, the first hemocyanin product was approved in 1997. Ever since, biosyn has been the leading manufacturer of high-quality, clinical-, GMP- and research-grade hemocyanin products extracted from the Giant Keyhole Limpet. The anticancer drugs, immunotherapeutics and carrier-proteins for vaccines evolved from this combination benefit patients around the globe.

To learn more about Good Manufacturing Practice (GMP) at biosyncorp, visit

Hope is the color blue. The unique IMMUCOTHEL® from the keyhole limpet indicated for the prevention of superficial bladder cancer recurrence.

What to do when the standard fails? Wasn't it enough that the patient suffered from superficial bladder cancer and now a post-TUR recurrence? After standard therapies were contraindicated, have been exhausted or were not tolerated in the first place, second-line treatment with IMMUCOTHEL® is indicated to prevent recurrences in superficial bladder cancer. This immunotherapeutic from biosyn is a safe, efficacious and well-established alternative to BCG. Thanks to its high tolerability and low rate of side effects, patients experience much less distress with IMMUCOTHEL®.