SummaryWe present data from a phase II study investigating a novel treatment strategy for relapsed/refractory mantle cell lymphoma (MCL). Twenty-six patients received lenalidomide 25 mg/d (days 1-21 of a 28-d cycle) for up to 6 cycles followed by low-dose maintenance lenalidomide (15 mg) in responding patients. Eight patients achieved complete or partial response to give an overall response rate of 31% with median response duration of 22Á2 months [95% confidence interval (CI) 0Á0-53Á6] and median progression-free survival (PFS) of 3Á9 months (95% CI 0Á0-11Á1). An additional six patients (23%) achieved stable disease. Eleven patients received maintenance with median PFS of 14Á6 months (95% CI 7Á3-21Á9). Correlative studies showed that peripheral T and Natural Killer (NK) cells increased in responding patients by 40-60% over the first 6 cycles with an initial dip in NK cells suggestive of tumour infiltration. Peripheral regulatory T cells were increased in MCL patients (P = 0Á001) and expanded further following lenalidomide. Sequential plasma analysis showed increased IL12 p40 and IL7 alongside decreased MMP9, IL10, and adiponectin. Finally, a significant correlation (P = 0Á02) between gender and response suggested that female MCL patients were more sensitive to lenalidomide than males. In summary, we confirm the activity, safety and immunomodulatory properties of lenalidomide in MCL and highlight its potential as a low-dose maintenance agent.

No abstract

The National Cancer Research Network (NCRN) is currently coordinating a Phase III randomised study (LY05) comparing fludarabine and cyclophosphamide (FC) with or without rituximab (R) for previously untreated mantle cell lymphoma (MCL). The combination of FC is well-recognised as significantly immunosuppressive and there are concerns that adding rituximab may increase infection risk further. The impact of rituximab on other markers of toxicity is also unclear. We analysed the toxicity data on 139 patients treated within the NCRN LY05 trial. Non-hematological toxicity was similar between the two treatment arms. The only difference in hematological toxicity was a higher rate of lymphocytopenia with fludarabine cyclophosphamide and rituximab (FCR), which did not translate into increased febrile episodes or infections. In conclusion, the addition of rituximab to FC for previously untreated MCL has no significant impact on toxicity.