By Bill Berkrot
NEW YORK (Reuters) Dec 07 - An experimental cancer drug has shown promising response rates in patients with relapsed and/or refractory multiple myeloma, according to interim data from a pair of small mid-stage trials.
The studies, presented on Monday at the American Society of Hematology (ASH) meeting in New Orleans, tested carfilzomib given intravenously every 28 days in 73 patients who had not previously been treated with bortezomib and in 33 others following bortezomib treatment.
"These interim results suggest that carfilzomib could benefit patients with multiple myeloma who are no longer responding to current therapies," Dr. David Siegel, co-investigator of the studies, said in a statement.
Among those not treated with bortezomib -- all of whom had relapsed or worsened after other therapies -- carfilzomib led to an overall response rate (ORR) of 46% among 54 patients on a 20 mg dose, and a 53% overall response among 19 patients with dose escalation to 27 mg, researchers said.
In contrast, patients who were previously treated with bortezomib achieved an overall response rate of 18% with carfilzomib, they said.
The trials also looked at time to progression and duration of response.
In the bortezomib-naive group, time to progression was 7.6 months, and duration of response was 8.4 months.
In the group previously treated with bortezomib, interim results showed a time-to-progression of 5.3 months and duration of response of more than 9 months.
"These findings are truly an advance for patients with multiple myeloma," Dr. Michael Wang, of the MD Anderson Cancer Center in Houston and one of the lead investigators, said.
Noting that other life-extending drugs often have adverse side effects, including severe nerve pain, Wang said "carfilzomib is showing good response rates with an improved side effects profile."
Treatment with carfilzomib was well tolerated with no unexpected side effects, researchers said.
More than 20% of patients were able to complete the full 12 cycles (48 weeks) of therapy in both studies without cumulative side effects, and with a low incidence of neuropathy, researchers said.
Michael Kauffman, interim chief medical officer of Onyx Pharmaceuticals Inc., the company that recently acquired carfilzomib, said in a statement that the company could file its application seeking U.S. approval by the end of 2010.
Reuters Health Information © 2009
Cite this: Carfilzomib Shows Promise in Multiple Myeloma Study - Medscape - Dec 07, 2009.