Bortezomib-based Triplet Regimens for Remission Induction in Multiple Myeloma

To compare the efficacy and side effect profile of different bortezomib-based triplet regimens for remission induction in patients with multiple myeloma (MM).

Observational study.

Armed Forces Bone Marrow Transplant Centre, Rawalpindi from January 2014 to December 2018.

A total of 81 patients of MM, were registered from January 2014 to December 2018. In final analysis, 44 out of 81 patients were included as per inclusion/exclusion criteria. Bortezomib-based regimens were used either as first line (in newly diagnosed) or as second line (in relapsed/refractory bortezomib naïve patients) therapy. Three different bortezomib-based triplet therapies were used (1) VCd, (2) VRd and (3) VTd. As there were only two patients in VTd regimen group so for study purposes VRd and VTd were grouped together, i.e. Vd with an IMiD. Response to treatment was assessed using the IMWG criteria. Comparison between different bortezomib-based regimens was performed in terms of their tolerability and response rate after four cycles of chemotherapy.

Out of 44 patients, 79.5% (n=35) patients received bortezomib-based triplet regimen as first line therapy, and in 20.5% (n=9) patients as second line therapy. VCd was administered to 56.8% (n=25) and Vd with an IMiD was used in 43.1% (n=19, VRd in 17 and VTd in 2) of the patients. Response was assessed at the end of fourth cycle. Overall response rate was comparable in both groups, 88% in VCd versus 89.4% in Vd with an IMiD group (p=0.432). In VCd and Vd with an IMiD group, CR was observed in 52% (n=13) and 57.9% (n=11) patients, respectively. Disease remained stable in 6.8% (n=3) patients. Treatment was generally well tolerated. Comparative analyses of both treatment groups revealed that the frequency of peripheral neuropathy was significantly higher in Vd with an IMiD group (47.3% vs 8% p=0.03). Grade III/IV neuropathy observed in 15.7% (n=3) of the patients in Vd with an IMiD group vs none in VCd group. Grade III/IV cytopenias were more seen in VCd group then in Vd with an IMiD group (16% vs. 5.2% p=0.16).

The overall response rates were comparable in VCd and Vd with IMiD, with a better side effect profile seen with VCd regimen. Key Words: Multiple myeloma, Bortezomib, Triplet therapy, Remission induction, Peripheral neuropathy.