ORCHARRD study results: ofatumumab-DHAP vs. rituximab-DHAP in R/R DLBCL, which is more effective?

In the Journal of Clinical Oncology in December 2016, Gustaaf W. van Imhoff from the University Medical Center Groningen, Netherlands, and colleagues published the results of the multi-center, randomized, ORCHARRD study, comparing the efficacy of ofatumumab (O) or rituximab (R) in combination with cisplatin, cytarabine, and dexamethasone (DHAP) in R/R DLBCL patients. Patients were recruited who were refractory to R-CHOP-like treatment or had their first relapse. In this study, patients were randomly assigned to receive either 3 cycles of ofatumumab (1,000mg) or rituximab (375mg/m²) plus DHAP, followed by Autologous Stem Cell Transplantation (ASCT). Patients responding following the second cycle of treatment were given the third cycle plus high-dose therapy and ASCT.

Key Highlights:

• 447 pts recruited between Mar 2010 and Dec 2013. 445 pts in ITT population
• Follow-up discontinued Nov 2014 as 80% of deaths had occurred, and 88% of PFS events
• 2-year PFS: O = 24%, R = 26% (P = 0.33, NS)
• 2-year OS: O = 41%, R = 38% (P = 0.38, NS)
• 2-year EFS: O = 16%, R = 18% (P = 0.35, NS)
• FDG-PET-response after third cycle was highly predictive of OS (P = 0.0018) and PFS (P = 0.001):
  • PET-positive 2-year PFS = 32%, OS = 43%
  • PET-negative 2-year PFS = 70%, OS = 78%
• AEs were similar across both treatment groups with 58% having one or more SAEs
• Most common SAEs: 13% febrile neutropenia, 5% acute renal failure, 5% thrombocytopenia

The authors concluded by stating that this study is the largest second-line DLBCL study with full FDG-PET response data after treatment and ASCT. The authors also stated that there was no statistical difference between using ofatumumab or rituximab in this treatment scenario, with neither regimen overcoming the treatment resistance of the patient’s disease. Further study needs to be done to identify potential treatment for these patients.