A phase II Bayesian sequential clinical trial in advanced Waldenström macroglobulinemia patients treated with bortezomib: interest of addition of dexamethasone

Abstract

In patients with advanced Waldenström macroglobulinemia (WM), overall response rate (ORR) and median progression-free survival (PFS) achieved with bortezomib alone and bortezomib rituximab combination were 27–85% and 7.9 months, and 81% and 16.4 months, respectively. We checked the role of dexamethasone in combination with bortezomib by enrolling in a phase II trial 34 patients with relapsed/refractory WM. Bortezomib (1.3 mg/m² IV D1, 4, 8, and 11 every 21 days) was used for six cycles. In non-responding patients, dexamethasone (20 mg daily for two days) was added to each infusion after the second cycle. After two cycles, the Bayes estimated ORR was 43.2 (95% Credible Interval: 28.0–59.1%) using the informative prior. Two-year survival rate was 84.0% and the median PFS 15.3 months without difference between patients treated with or without dexamethasone. We conclude that dexamethasone must be associated to bortezomib-based regimen.

Keywords:

• Dexamethasone
• bortezomib
• Waldenström macroglobulinemia
• Bayes

Acknowledgements

The authors wish to thank patients for accepting to participate in the trial.

This trial was supported by the French National Cancer Institute (INCA) through the “Programme Hospitalier de Recherche Clinique (PHRC N°AOM 06197/P060207)” funded this trial.

Potential conflict of interest

Disclosure forms provided by the authors are available with the full text of this article online at http://dx.doi.org/10.1080/10428194.2017.1307357.

Additional information

Funding

This trial was supported by the French National Cancer Institute (INCA) through the “Programme Hospitalier de Recherche Clinique (PHRC N°AOM 06197/P060207)” funded this trial.