PATIENTS with late line relapsed/refractory multiple myeloma (RRMM) could benefit from repeat treatment with drugs their disease has previously been refractory to, according to new research performed by the Mayo Clinic, Rochester, Minnesota, USA.
Utkarsh Goel and colleagues explored the role of retreatment with previously refractory therapies in response to the progress made in life expectancy for patients with RRMM, who could have been exposed to multiple available treatments over their disease course. They postulated that for those with prior exposure to multiple therapies, or those without access to newer treatments, retreating with a previously refractory drug could be a viable treatment option.
The team retrospectively reviewed data from 315 patients registered at the Mayo Clinic, with a diagnosis of RRMM, who received retreatment with a drug they had been refractory to in the past. The median age at the time of retreatment was 61 years, 42% were female, and the median duration of follow-up from retreatment was 56 months.
Interestingly, the analysis revealed an overall response rate of 56.2% in these patients and a median progression free survival (PFS) of 11 months (95% CI: 9–13). Following retreatment, PFS was longer in those with a greater time lapse between initiation of the index therapy they became refractory to and retreatment (>46.1 months) than those with a shorter duration between initial treatment and retreatment, with a PFS of 28.2 months compared to 8.9 months (p=0.016), respectively.
Furthermore, PFS was found to be greater in those who received the index drug for >28.4 months than in those who received the index drug for <28.4 months, with a median PFS of 16.9 months compared to 8.1 months (p<0.001), respectively.
From these findings, the authors concluded that retreating RRMM with previously refractory drugs provides a feasible treatment option, and that those who were initially sensitive to the index treatment, and those who had a longer break between initial treatment and retreatment, experienced the most benefit from the retreatment strategy. They recommended that this option could be considered for those without access to newer treatments and those who have been exposed to the majority of available treatments.
Reference
Goel U et al. Retreatment of multiple myeloma with previously refractory drugs. Blood Adv. 2024;DOI:10.1182/bloodadvances.2024014723.
