For patients with newly diagnosed mantle cell lymphoma, duration and quality of response were superior with a regimen of bortezomib, rituximab, cyclophosphamide, doxorubicin, and prednisone (VR-CAP) when compared with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP), based on a post hoc analysis of the randomized, phase III LYM-3002 trial.
The difference was especially evident among patients who had a low- or medium-risk mantle cell lymphoma international prognostic index, Gregor Verhoef, MD, of University Hospital Leuven (Belgium) and his associates wrote in Haematologica.
In LYM-3002, 487 patients with newly diagnosed stage II-IV mantle cell lymphoma received six to eight 21-day cycles of intravenous VR-CAP or R-CHOP. Although overall response rates were similar for both groups, VR-CAP was associated with better duration of response and progression-free survival (PFS) and extended time to next treatment. To further explore these differences, the post hoc analysis stratified outcomes by response categories and analyzed depth of response based on computed tomography (CT) scans. Patients had a median age of about 65 years, and most were white males with stage-IV disease at diagnosis and an Eastern Cooperative Oncology Group performance status of 1 (Haematologica. 2017 Feb 9. doi: 10.3324/haematol.2016.152496).The superiority of VR-CAP held up across response categories. Complete responders to VR-CAP had more than twice the median PFS as did complete responders to R-CHOP (40.9 vs. 19.8 months; hazard ratio, 0.58; 95% confidence interval, 0.39-0.84; P = .004). Among partial responders, median PFS was 17.1 vs. 11.7 months, respectively (HR, 0.62; 95% CI, 0.43-0.89; P = .01). Respective median duration of overall response was 42.1 months for VR-CAP vs. 18.5 months among complete responders (HR, 0.42; P less than .001), and 20.2 vs. 9.6 months among partial responders (HR, 0.57; P = .006).
Median time to next treatment also favored VR-CAP over R-CHOP among both complete responders (not evaluable vs. 26.6 months; HR, 0.42; P less than .001) and partial responders (35.3 vs. 24.3 months; HR, 0.57; P = .006), the researchers said. Further, CT scans showed that proportionally more patients in each response category became lesion-negative on VR-CAP than on R-CHOP. Among complete responders, rates of lesion negativity were 72% and 59%, respectively. Among partial responders, rates were 48% and 28%.
The effects of VR-CAP were most evident among patients with a low or medium-risk mantle cell lymphoma international prognostic index. Perhaps high-risk status signifies more rapidly proliferative disease, which negates the deeper responses with VR-CAP, compared with R-CHOP, they added.
The LYM-3002 study was supported by Janssen Research & Development and Millennium Pharmaceuticals. Dr. Verhoef had no disclosures. Nine coinvestigators disclosed ties to Janssen, Roche, GlaxoSmithKline, and several other pharmaceutical companies.