Evaluation of disease-free survival as an intermediate metric of overall survival in patients with localized renal cell carcinoma: A trial-level meta-analysis : DFS as a Metric of Overall Survival in RCC

Cabozantinib is an oral inhibitor of tyrosine kinases including MET, VEGFR, and AXL. The randomised phase 3 METEOR trial compared the efficacy and safety of cabozantinib versus the mTOR inhibitor everolimus in patients with advanced renal cell carcinoma who progressed after previous VEGFR tyrosine-kinase inhibitor treatment. Here, we report the final overall survival results from this study based on an unplanned second interim analysis.

Therapeutic prostate-specific antigen (PSA) -targeted poxviral vaccines for prostate cancer have been well tolerated. PROSTVAC-VF treatment was evaluated for safety and for prolongation of progression-free survival (PFS) and overall survival (OS) in a randomized, controlled, and blinded phase II study. In total, 125 patients were randomly assigned in a multicenter trial of vaccination series. Eligible patients had minimally symptomatic castration-resistant metastatic prostate cancer (mCRPC). PROSTVAC-VF comprises two recombinant viral vectors, each encoding transgenes for PSA, and three immune costimulatory molecules (B7.1, ICAM-1, and LFA-3). Vaccinia-based vector was used for priming followed by six planned fowlpox-based vector boosts. Patients were allocated (2:1) to PROSTVAC-VF plus granulocyte-macrophage colony-stimulating factor or to control empty vectors plus saline injections. Eighty-two patients received PROSTVAC-VF and 40 received control vectors. Patient characteristics were similar in both groups. The primary end point was PFS, which was similar in the two groups (P = .6). However, at 3 years post study, PROSTVAC-VF patients had a better OS with 25 (30%) of 82 alive versus 7 (17%) of 40 controls, longer median survival by 8.5 months (25.1 v 16.6 months for controls), an estimated hazard ratio of 0.56 (95% CI, 0.37 to 0.85), and stratified log-rank P = .0061. PROSTVAC-VF immunotherapy was well tolerated and associated with a 44% reduction in the death rate and an 8.5-month improvement in median OS in men with mCRPC. These provocative data provide preliminary evidence of clinically meaningful benefit but need to be confirmed in a larger phase III study.

A phase III trial of bevacizumab combined with interferon alfa-2a (IFN) showed significant improvements in progression-free survival (PFS) in metastatic renal cell carcinoma (mRCC). Here, we report overall survival (OS) data. Six hundred forty-nine patients with previously untreated mRCC were randomly assigned to receive bevacizumab (10 mg/kg every 2 weeks) plus IFN (9 MIU subcutaneously three times a week; n = 327) or IFN plus placebo (n = 322) in a multicenter, randomized, double-blind, phase III trial. The primary end point was OS. Final analysis of the secondary end point (PFS) was reported earlier. Median OS was 23.3 months with bevacizumab plus IFN and 21.3 months with IFN plus placebo (unstratified hazard ratio [HR] = 0.91; 95% CI, 0.76 to 1.10; P = .3360; stratified HR = 0.86; 95% CI, 0.72 to 1.04; P = .1291). Patients (> 55%) in both arms received at least one postprotocol antineoplastic therapy, possibly confounding the OS analysis. Patients receiving postprotocol therapy including a tyrosine kinase inhibitor had longer median OS (bevacizumab plus IFN arm: 38.6 months; IFN plus placebo arm: 33.6 months; HR = 0.80; 95% CI, 0.56 to 1.13). Tolerability was similar to that reported previously. Bevacizumab plus IFN is active as first-line treatment in patients with mRCC. Most patients with mRCC receive multiple lines of therapy, so considering the overall sequence of therapy when selecting first-line therapy may optimize patient benefit.