Trisenox combination regimen induces high rate of responses in patients with late-stage, relapsed or refractory multiple myeloma
(11 April 2005: VIDYYA MEDICAL NEWS SERVICE) -- At the 10th International Myeloma Workshop, James Berenson, M.D., Medical & Scientific Director of the Institute for Myeloma & Bone Cancer Research presented data from a multicenter, phase II trial of a Trisenox combination regimen, known as MAC (melphalan, Trisenox and vitamin C), in relapsed or refractory multiple myeloma patients. The data showed that 22 of the 37 patients evaluated (60 percent) achieved an objective response, with eight patients experiencing a decrease in serum M-protein of 50 percent or more and 14 patients experiencing a decrease in serum M-protein of between 25 to 49 percent. Of the twenty-nine patients who had failed prior thalidomide or lenolinamide therapy, 14 patients responded to the Trisenox regimen. In addition,
seven out of 10 patients who had failed bortezomib therapy responded and 10 out of 16 patients who had received prior melphalan
therapy responded. The regimen was well tolerated. The few significant adverse events included mild cytopenias, fluid retention,
and neuropathy. Trisenox (arsenic trioxide) is marketed in the United States and Europe by Cell Therapeutics, Inc. (CTI) (Nasdaq:
CTIC; Nuovo Mercato).
"In addition to the impressive response rates reported in this group of heavily pretreated patients, who had received an average
of approximately four prior regimens (range of one to eight) prior treatments, the MAC regimen resulted in a marked improvement
in the serum creatinine levels in patients with renal insufficiency," stated Berenson. "The regimen is very well tolerated
and gives patients another option besides high-dose dexamethasone which can have severe side effects. The median duration
of response has not been reached, but responses have been durable with."
This study will continue to accrue to a target enrollment of 60 evaluable patients. For more information about this presentation,
please visit the CTI website at the following link http://www.cticseattle.com/investors_news-updates.htm.
Trisenox(R) (arsenic trioxide) is marketed by CTI. Trisenox was approved for marketing in 2000 by the U.S. Food and Drug Administration
to treat patients with relapsed or refractory acute promyelocytic leukemia (APL), a rare, life-threatening form of cancer
of the blood. Trisenox was granted marketing authorization from the European Commission in March 2002. APL, one of eight subtypes
of acute myeloid leukemia (AML), represents 10-15 percent of the more than 20,000 patients diagnosed with AML each year. Trisenox
is currently being studied in more than 40 clinical and investigator-sponsored trials in a variety of cancers.
U.S. marketing approval for Trisenox was granted based on results from a U.S. multicenter study in which 40 relapsed APL patients
were treated with Trisenox 0.15 mg/kg until bone marrow remission or a maximum of 60 days. Thirty-four patients (85 percent)
achieved complete remission. When the results for these 40 patients were combined with those for the 12 patients in a pilot
trial, an overall response rate of 87 percent was observed.
WARNING: Trisenox should be administered under the supervision of a physician who is experienced in the management of patients
with acute leukemia. Some patients with APL treated with Trisenox have experienced APL differentiation syndrome -- with symptoms
similar to retinoic acid-acute promyelocytic leukemia (RA-APL) syndrome. Arsenic trioxide can cause QT prolongation (which
can lead to torsade de pointes) and complete atrioventricular block.
The most common adverse events associated with Trisenox have been generally manageable, reversible and usually did not require
interruption of therapy. These have included hypokalemia, hypermagnesemia, hyperglycemia and thrombocytopenia as reported
in 13 percent of the patients (n=40). Abdominal pain, dyspnea, hypoxia, bone pain and neutropenia were reported in 10 percent
of these patients, while arthralgia, febrile neutropenia and disseminated intravascular coagulation were reported in eight
percent of patients.
Return to Vidyya Medical News Service for 11 April 2005