Vasostatin as marrow protectant

Patent Number: 7,432,236

Destruction of the bone marrow by chemotherapy or radiotherapy causes significant morbidity and mortality.  In fact, hematopoietic toxicity is the main limiting factor of many types of chemotherapeutic agents.  Accordingly, it would be interesting if one were to develop an agent or therapeutic approach that could protect the bone marrow, or alternatively, allow bone marrow cells to proliferate rapidly after an insult.  Various types of bone marrow protectors have been patented, for example, patent # 5,114,926 teaches the use of a tetrapeptide to protect the hematopoietic stem cell compartment from cytotoxic injury.  Another way of protecting the hematopoietic stem cell is through the systemic administration of TGF-beta before the bone marrow insult as described in patent # 5,278,145.

The current patent, which is related to the previously issued #6,596,690, teaches the use of vasostatin and vasostatin derived peptides for acceleration of bone marrow reconstitution after myeloablative insults.  The independent claim reads "A method for stimulating the proliferation of a hematopoietic cell in a subject treated with a chemotherapeutic agent or ionizing radiation for cancer therapy in said subject, comprising administering to said subject a peptide comprising the amino acid sequence set forth as SEQ ID NO: 6, thereby stimulating the proliferation of the hematopoietic cell in the subject treated with the chemotherapeutic agent or ionizing radiation."

Vasostatin is a fragment of calreticulin and is involved in inhibition of angiogenesis.  This is a very useful aspect since a lot of the cancer patients would benefit from the added effect of inhibiting angiogenesis.  Another useful aspect of vasostatin is that it is easy to manufacture and has a relatively good safety profile.

View this patent on the USPTO website.