A phase II trial of RCHOP followed by radioimmunotherapy for early stage (stages I/ II ) diffuse large B‐cell non‐Hodgkin lymphoma: ECOG 3402

Summary Patients with early stage diffuse large B‐cell lymphoma ( DLBCL ) receive RCHOP (rituximab cyclophosphamide, doxorubicin, vincristine, prednisone) alone or with involved field radiotherapy ( IFRT ). Anti‐ CD 20 radioimmunotherapy ( RIT ) delivers radiation to microscopic sites outside of known disease. This phase II study aimed to achieve a functional complete response ( CR ) rate of ≥75% to RCHOP and 90 Yttrium‐ibritumomab tiuxetan RIT . Patients with stages I/ II DLBCL received 4–6 cycles of RCHOP followed by RIT [14·8 MBq/kg (0·4 mCi/kg)]; patients with positron emission tomographypositive sites of disease after RCHOP / RIT received 30 Gy IFRT . Of the 62 patients enrolled; 53 were eligible. 42% (22/53) had stage I/ IE ; 58% (31/53) stage II / IIE . After RCHOP , 79% (42/53) were in CR /unconfirmed CR . Forty‐eight patients proceeded to RIT . One partial responder after RIT received IFRT and achieved a CR . The best response after RCHOP  +  RIT in all 53 patients was a functional CR rate of 89% (47/53; 95% confidence interval: 77–96%). With a median follow‐up of 5·9 years, 7 (13%) patients have progressed and 4 (8%) have died (2 with DLBCL ). At 5 years, 78% of patients remain in remission and 94% are alive. Chemoimmunotherapy and RIT is an active regimen for early stage DLBCL patients. Eighty‐nine percent of patients achieved functional CR without the requirement of IFRT . This regimen is worthy of further study for early stage DLBCL in a phase III trial.