Rituximab maintenance demonstrates survival benefit after chemotherapy in lymphoma subtype

ATLANTA — Rituximab maintenance after rituximab plus CHOP chemotherapy demonstrated significantly prolonged PFS and OS in first-line treatment of older patients with mantle cell lymphoma who were not eligible for autologous stem cell transplantation, according to results from a long-term follow-up study presented at the ASH Annual Meeting and Exposition.

Previously, in 2004, the European MCL Network performed the MCL Elderly trial for the first-line treatment of patients with MCL aged 60 years or older and not suitable for ASCT.

The primary analysis demonstrated that rituximab (Rituxan; Genentech, Biogen) plus FC chemotherapy did not improve complete remission rates when compared with rituximab plus CHOP chemotherapy. Additionally, the initial results demonstrated a prolonged PFS in patients in remission with the use of rituximab maintenance when compared with interferon-alpha maintenance.

Eva Hoster, PhD, of the Medical Center of the University of Munich, and colleagues presented long-term follow-up of the time-to-event endpoints after a median follow-up of 6.7 years.

Failure-free survival after the start of rituximab plus FC chemotherapy or rituximab plus CHOP chemotherapy induction overlapped with 5-year probabilities of 31% in each group.

The long-term follow-up results also demonstrated that although rituximab plus FC chemotherapy demonstrated a reduction in 5-year cumulative incidence of treatment failure compared with rituximab plus CHOP chemotherapy (51% vs. 60%), the cumulative incidence of death without treatment failure was greater with rituximab plus FC chemotherapy (19% vs. 9%).

OS was shorter after rituximab plus FC chemotherapy with a 5-year probability of 42% (36%-49%) compared with 58% (51%-64%) after rituximab plus CHOP chemotherapy.

Additionally, rituximab maintenance after first-line treatment significantly prolonged PFS from the end of induction when compared with interferon-alpha maintenance (P = .0109). Median 5-year PFS with rituximab was 53% compared with 23% with interferon-alpha maintenance.

Five-year PFS with rituximab maintenance was 51% vs. 22% with interferon-alpha maintenance after initial response to rituximab plus CHOP chemotherapy (P < .0001).

Additionally, 5-year OS was significantly prolonged in rituximab maintenance (79%) compared with interferon-alpha maintenance (59%) after rituximab plus CHOP chemotherapy.

However, rituximab maintenance after rituximab plus FC chemotherapy had a significantly reduced 5-year OS (57%).

After 5 years of follow-up, 32% of patients (n = 82) receiving rituximab maintenance after rituximab plus CHOP chemotherapy remained on treatment. Thirty-three percent had to stop treatment early. More than half (58%) of patients (n = 83) receiving interferon-alpha maintenance had stopped treatment early after 5 years, while only 5% remained on therapy.

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“Six cycles of rituximab plus FC chemotherapy is effective in terms of ... activity, but it was shown to be too toxic for application in the first-line treatment,” Hoster said during her presentation. “We can also clearly see that rituximab maintenance is effective after first-line treatment of rituximab plus FC chemotherapy, but, we see that it is [also] too toxic. [However], eight cycles of rituximab plus CHOP chemotherapy followed by rituximab maintenance is effective with good long-term outcomes.” – by Ryan McDonald

Reference:

Hoster E, et al. Abstract 153. Presented at: ASH Annual Meeting and Exposition; Dec. 9-12, 2017; Atlanta.

Disclosures: Hoster reports research funding and travel support from Roche.