In Lee et alr, 229 patients were evaluated for response to two cycles of DT-PACE for induction. The partial remission rate (PR) after 2 cycles of DT-PACE was 32%, with 16% attaining a complete response (CR) or near-CR (n-CR) (defined as only immunofixation electrophoresis-positive). Patients who received a 100% dose of DT-PACE for two cycles (n = 115) achieved higher response rates than those with less than 100% dose (n = 121): PR or better, 49% vs 17% (p < 0.0001); CR + nCR, 27% vs 6% (p < 0.0001).
Patients with high lactate dehydrogenase (LDH) (n = 98) showed a better response than those with a normal LDH (n = 138): PR or better 43% vs 27% (p = 0.01), CR + nCR, 25% vs 11% (p = 0.01). Patients with chromosome 13 abnormalities (n = 55) responded equally well as the other patients (n = 181): PR or better, 35% vs 33% (p = 0.84); CR + nCR, 17% vs 15% (p = 0.73).r
In Gerrie et alr, of the 75 patients evaluated 90% completed a median of two cycles. 50% (n = 37) completed one cycle and 40% (n = 30) two cycles. Overall response rate (ORR) was 49% (partial response 33% and very-good partial response 16%). An additional 36% of patients had stable disease (SD) and 9% progressed on treatment. CR rates were not reported.
The median progression-free survival (PFS) was 5.5 months (95% CI 4.3-9.8) and median OS 14 months (95% CI 8.7-19.3). However, 35 of 64 patients who responded or had stable disease proceeded to ASCT or a clinical trial with median PFS for this subset of 13.4 months (CI 7.7-20.1), and median OS 20.5 months (CI 14.8-63.8).r
Eastern Cooperative Oncology Group status (ECOG) 3 - 4 patients had significantly poorer OS (5.5. vs 15.9) and PFS (2.6 vs 5.5 months) in comparison to ECOG status 0-2 patients. Those who had already received a prior ASCT had poorer outcomes (OS 7.5 vs no prior ASCT 15.9).r
A phase 2 study ‘The Total Therapy 3’r added bortezomib (1.0 mg/m2 on days 1,4,8 and 11) to the DT PACE backbone for 303 newly diagnosed patients with myeloma. Induction chemotherapy prior to and consolidation chemotherapy after tandem transplants each consisted of two cycles of VTD-PACE (bortezomib, thalidomide, dexamethasone and 4-day continuous infusions of cisplatin, doxorubicin, cyclophosphamide, etoposide) with the thalidomide dose capped at 200 mg daily. At 24 months, 83% had completed near-complete remission.