Rivaroxaban approved for the treatment of DVT and PE

Rivaroxaban approved for the treatment of DVT and PE

In early November 2012, the FDA expanded the approved use of rivaroxaban (brand name Xarelto) to be used for the treatment of blood clots in deep veins (deep venous thrombosis, DVT) and in pulmonary arteries (pulmonary embolism, PE).  Rivaroxaban was originally approved for the treatment of patients with atrial fibrillation. DVT and PE are major health concerns in the United States with about 300,000 patients diagnosed annually.  It is estimated that DVT and PE are the cause of 100,000 deaths per year.

The standard treatment for these conditions in the US has consisted of starting patients on unfractionated heparin or low molecular weight heparin  followed by a Vitamin K antagonist (Coumadin or warfarin). This treatment requires frequent blood monitoring.

Analysis of the Einstein PE trial showed that rivaroxaban, which does not require regular monitoring, is not inferior to the standard treatment.

One word of caution regarding the results: only 5% of patients in the Einstein PE trial had malignancies and clearly more data are needed before rivaroxaban can be uniformly recommended for patients with cancer and DVT/PE. 

New treatments for Chronic Myelogenous Leukemia (CML)

New treatments for Chronic Myelogenous Leukemia (CML)

In the United States, about 5500 patients per year will be diagnosed with CML; a chronic leukemia associated with high white blood cell counts and other blood count abnormalities; which in the past was only curable with a bone marrow transplant.  However for the last 12 years, treatment with an oral drug called imatinib (brand name Gleevec), which belongs to a class of drugs called tyrosine kinase inhibitors, has been a major breakthrough in that many patients who were started on Gleevec saw their chronic leukemia disappear. Patients do have to remain on the medication indefinitely, otherwise the chronic leukemia could come back.

Over the years, two other oral drugs (dasatinib and nilotinib) which are even more successful than imatinib have been approved for the treatment of CML. However, there are CML patients who do not see their chronic leukemia go away with Gleevec or even when treated with dasatinib or nilotinib.

For those patients, treatment with bosutinib may be an option. The drug was approved by the FDA in September 2012 for patients who did not benefit from treatment with imatinib,dasatinib or nilotinib. Patients who had been on imatinib, in particular, experienced significant improvement of their chronic leukemia when they took bosutinib.

When CML cells become resistant to standard treatment, it is usually through specific mutations of certain proteins within the cell. One particularly feared mutation is the T315I mutation which confers resistance to all oral anti-CML medications. There is a promising new drug called ponatinib which in one study resulted in complete normalization of blood counts of all patients who had the T315I mutation. I am happy to report that ponatinib received FDA approval on December 7, 2012 giving patients with standard-treatment-resistant CML a promising treatment option. The brand name of ponatinib is going to be Iclusig.

Lastly, the FDA recently approved another drug for the treatment of CML called omacetaxine (brand name Synribo) which has to be injected under the skin twice daily on certain days of the month. It may play a role in the treatment of patients who cannot tolerate any of the other FDA-approved anti-CML drugs or those who have not responded to them.