Currently, there is no standard systemic treatment for extranodal
marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue. Both
rituximab and
cladribine have shown some activity in this disease, but the combination has not been tested so far. In view of this, we initiated a phase II study to assess the activity and safety of
rituximab and
cladribine in patients with histologically verified
mucosa-associated lymphoid tissue lymphoma. Treatment consisted of
rituximab 375 mg/m(2) i.v. day 1 and
cladribine 0.1 mg/kg s.c. days 1 - 4 every 21 days. In case of complete remission after two courses, another two cycles of
therapy were administered, while patients with a partial response or stable disease were scheduled to receive six cycles of treatment. Out of 40 evaluable patients (14 female, 26 male), 39 received treatment as scheduled while one patient died before initiation of
therapy and was rated as having progressive disease in the intent-to-treat analysis. Twenty-one patients had
gastric lymphoma, while 19 suffered from extragastric
mucosa-associated lymphoid tissue lymphoma. Side effects consisted mainly of hematologic toxicity including
leukopenia,
lymphopenia,
anemia and
thrombocytopenia. Twenty-three patients had a complete remission (58%) and nine had a partial remission (23%) for an overall response rate of 81%, while five had stable disease (13%) and two progressed during
therapy. After a median follow-up of 16.7 months (interquartile range: 15.9 - 18.7 months), 35 patients are alive (88%) while four patients have died and one patient withdrew consent and did not allow further follow up. Our data demonstrate that
rituximab plus
cladribine is active and safe in patients with
mucosa-associated lymphoid tissue lymphoma.