Response after just two cycles of a bortezomib-based induction therapy appears to predict depth of response at the end of induction and subsequent survival in patients with multiple myeloma.
The findings, from a review of patients treated between 2009 and 2016 at Monash Health, suggest non-responders can be identified early and may require an escalation of therapy.
Failure to achieve at least a partial response following cycle 2 was associated with an overall survival of 43 months compared to 58.5 months in responders.
There was no difference in the rate of autologous stem cell transplant between the groups to account for the survival rates.
Co-author Dr Pasquale Fedele, a haematologist at Monash Health, told the limbic there was currently no consensus on how to manage patients who fail to achieve an optimal early response or even what an optimal response was.
“Often if patients had achieved a minimal response or even stable disease they are likely to be continued on the same regimen,” he said.
“We have found that patients who do not at least achieve a partial response, by international myeloma working group criteria, have worse survival outcomes if they just continue on with current their treatment.”
He said options for escalating treatment would need to be evaluated in future trials.
“Hypothetically, for a patient on bortezomib who has not achieved a partial response by cycle 2, possible escalation could be the addition of lenalidomide or switch to a second generation proteasome inhibitor with the addition of lenalidomide.”
The study of 115 patients found most (81%) achieved at least a partial response.
However ISS staging at baseline, R-ISS staging and cytogenetics did not help predict who would respond early and who wouldn’t.
“The power of current staging strategies is very limited. A greater understanding of the underlying disease biology driving an individual patient’s disease, an appreciation of the different clones within the same patient, and how this influences responses to specific therapies is needed.”