Pomalidomide, bortezomib and dexamethasone for multiple myeloma relapsed after lenalidomide treatment

This study aimed to investigate the outcomes for patients with multiple myeloma (MM) who were treated with pomalidomide (Pomalyst), bortezomib (Velcade), and dexamethasone (Decadron) after relapsing following lenalidomide (Revlimid) treatment. 

This study concluded that this treatment combination was effective in these patients as a second-line treatment.  

Lenalidomide is a standard treatment for patients newly diagnosed with MM. However, many patients become unresponsive to this treatment and need second-line therapies. Bortezomib and dexamethasone (Vd) is a standard treatment for patients with relapsed and refractory (unresponsive) MM. 

Pomalidomide is a drug similar to lenalidomide that can be used as a treatment for relapsed and refractory multiple myeloma (MM). It acts as an anti-angiogenic (stops blood to the tumor) and immunomodulator (changes immune response). 

Second-line pomalidomide, bortezomib, and dexamethasone (PVd) has shown better effectiveness than Vd in patients with relapsed/refractory MM (R/R MM), who were previously treated with lenalidomide. However, it was unknown if PVd was safe and effective in patients with R/R MM after the first-time relapse (after 1 type of treatment only). 

This study involved 226 patients with r/r MM after only one line of treatment. Patients were grouped based on lenalidomide-refractory status, prior bortezomib exposure, and prior stem cell transplant (SCT). 57.1% of the patients were lenalidomide-refractory. Patients were treated with Vd or PVd as a second-line treatment.  

Overall, progression-free survival (PFS) was 20.73 months for the PVd group compared to 11.63 months for the Vd group in all patients. In the lenalidomide-refractory group, PFS was 17.8 months with PVd compared to 9.5 months with Vd. In the lenalidomide-nonrefractory group, PFS was 22 months with PVd compared to 12 months with Vd.  

Overall, 90.1% of patients in the PVd group responded to treatment compared to 54.8% to Vd, regardless of lenalidomide status. PVd led to a better response in both lenalidomide-refractory patients (85.9%) and lenalidomide-nonrefractory patients (95.7%) compared to Vd (50.8% in lenalidomide-refractory and 60% in lenalidomide-nonrefractory).

In patients with previous bortezomib treatment, PVd also resulted in better PFS (17.8 months) compared to Vd (12 months). PVd also led to better PFS in those without previous bortezomib treatment compared to Vd (20.7 months vs 9.5 months).

PFS was 22 months for the PVd group compared to 13.8 months for the Vd group in patients with prior SCT. PFS was 16.5 months for the PVd group compared to 9.5 months for the Vd group in patients without prior SCT. 

90.6% of the PVd group and 71% of the Vd group experienced severe side effects. The most common side effects in both groups were low white blood cells and low platelet (blood cells involved in clotting) levels.

This study concluded that PVd treatment was more effective than Vd as a second-line treatment in patients with r/r MM, including those who had lenalidomide as first line treatment.  

This study was funded by Celgene, the manufacturer of pomalidomide.