Randomized Phase III Trial of Dose-dense Methotrexate, Vinblastine, Doxorubicin, and Cisplatin, or Gemcitabine and Cisplatin as Perioperative Chemotherapy for Patients with Muscle-invasive Bladder Cancer. Analysis of the GETUG/AFU V05 VESPER Trial Secondary Endpoints: Chemotherapy Toxicity and Pathological Responses

Background: Perioperative chemotherapy (neoadjuvant or adjuvant) has been developed to increase overall survival for nonmetastatic muscle-invasive bladder cancer (MIBC). Retrospective studies or prospective phase II trials have been reported to use dose-dense methotrexate, vinblastine, doxorubicin, and cisplatin (dd-MVAC) or gemcitabine and cisplatin (GC). As dd-MVAC has shown higher response rates in metastatic disease, better efficacy is expected in the perioperative setting.

Objective: We designed a randomized phase III trial to compare the efficacy of dd-MVAC or GC in MIBC perioperative (neoadjuvant or adjuvant) setting.

Design, setting and participants: A total of 500 patients were randomized from February 2013 to March 2018 in 28 centers and received either six cycles of dd-MVAC every 2 wk or four cycles of GC every 3 wk.

Outcome measurements and statistical analysis: The primary endpoint (progression-free survival at 3 yr) was not reported. We focused on secondary endpoints: chemotherapy toxicity and pathological responses.

Results and limitations: In the neoadjuvant group, 218 patients received dd-MVAC and 219 received GC. Of the patients, 60% received six cycles in the dd-MVAC arm and 84% received four cycles in the GC arm; 199 (91%) and 198 (90%) patients underwent surgery, respectively. Complete pathological response (ypT0pN0) was observed in 84 (42%) and 71 (36%) patients, respectively (p=0.2). An organ-confined status (<ypT3pN0) was obtained in 154 (77%) and 124 (63%) patients, respectively (p=0.001). In the adjuvant group, 40% of patients received six cycles in the dd-MVAC arm and 60% received four cycles in the GC arm. Most of Common Terminology Criteria for Adverse Events (CTCAE) grade ≥3 toxicities concerned hematological toxicities, reported for 129 (52%) patients in the dd-MVAC group and 134 (55%) patients in the GC group. Gastrointestinal (GI) grade ≥3 disorders were more frequently observed in the dd-MVAC arm (p=0.003), as well as asthenia of grade ≥3 (p<0.001).

Conclusions: The toxicity of dd-MVAC was manageable with more severe asthenia and GI side effects than that of GC in perioperative chemotherapy. A higher local control rate (complete pathological response, tumor downstaging, or organ confined) was observed in the dd-MVAC arm (p=0.021). However, such data have to be confirmed on progression-free survival, with primary endpoint data expected in mid-2021.

Patient summary: The authors have designed a randomized phase III controlled study comparing the efficacy of gemcitabine and cisplatin, and dose-dense methotrexate, vinblastine, doxorubicin, and cisplatin (dd-MVAC) in patients for whom chemotherapy has been decided, before or after radical cystectomy. Higher toxicity regarding asthenia and gastrointestinal side effects along with a better bladder control rate were observed in the dd-MVAC arm. However, such data have to be confirmed on progression-free survival, with primary endpoint data expected in mid-2021.