Newly diagnosed multiple myeloma patients who achieved a complete response to the combination of Velcade, melphalan, and prednisone experienced longer time to disease progression, time to next therapy, and treatment-free interval compared to patients who achieved a partial response. 

The benefits associated with complete response were similar regardless of whether complete response was achieved early or late in the treatment course.

Based on these findings, the researchers concluded that the achievement of a complete response should be considered an important treatment goal. They recommended that VMP be continued in patients tolerating therapy, thereby improving response and clinical benefit.

These findings resulted from further analysis of a Phase 3 clinical trial known as VISTA, which compared the efficacy of Velcade (bortezomib), melphalan (Alkeran), and prednisone (VMP) to melphalan and prednisone (MP) alone in newly diagnosed multiple myeloma patients ineligible for stem cell transplantation.  

Results of the VISTA trial had demonstrated that patients on VMP had better response rates and longer overall survival than patients on MP. In particular, 30 percent of patients treated with VMP achieved a complete response compared to 4 percent of patients treated with MP.

In their follow-up analysis, the researchers analyzed the trial data further to see if the achievement of a complete response was associated with improved outcome.

The researchers found that the time to disease progression, time to next therapy, and the treatment-free interval were all longer in patients who achieved a complete response compared to patients who achieved a partial response, regardless of treatment with VMP or MP. 

The overall survival, however, was not statistically different between patients who achieved a complete response and patients who achieved a partial response.   

In particular, for patients on VMP treatment, the median time to progression has not yet been reached for patients who achieved a complete response, whereas it was 21.7 months in patients who achieved a partial response.  

With a complete response on VMP, the median time to next therapy was 37.8 months and the median treatment-free-interval was 29.9 months, compared to a median time to next therapy of 25.2 months and a median treatment-free interval of 13.9 months in patients who achieved a partial response.

Further analysis was completed on patients who received VMP to evaluate if the timing of the response affected outcome in these patients. 

Researchers found that the quality of response improved with prolonged VMP treatment.

Although most patients achieved best responses within the first four cycles of therapy, 28 percent of complete responses were achieved after four cycles. 

For more information, please see the study in the scientific journal Blood (abstract).