Treatment Benefit of Daratumumab for Multiple Myeloma Supported by 3-Year Follow-Up Data

Jacob Laubach, MD, oncologist at the Dana-Farber Cancer Institute, discusses updated safety and efficacy data from the phase 2 GRIFFIN trial assessing daratumumab plus lenalidomide, bortezomib, and dexamethasone in newly diagnosed multiple myeloma patients. The data were recently presented at The American Society of Hematology Meeting & Exposition (ASH 2021).

Multiple myeloma is a rare blood cancer associated with uncontrolled growth of plasma cells. Abnormal plasma cells – also known as myeloma cells – interfere with the production of healthy blood cells in the bone marrow. Myeloma cells also produce inactive clones of abnormal antibodies that may negatively affect the bones and kidneys. Symptoms of multiple myeloma may include: bone pain (particularly in the chest and spine), frequent infections, weakness or numbness in the legs, fatigue, confusion, excessive thirst, and constipation. While the disease is treatable, relapses are common and some patients are refractory to first line treatment.

As Dr. Laubach explains, in the primary analysis of the GRIFFIN trial (NCT02874742) (median follow-up of 13.5 months), daratumumab plus lenalidomide, bortezomib, and dexamethasone (D-RVd) improved the rate of stringent complete response (sCR) by the end of post-autologous stem cell transplant consolidation versus lenalidomide, bortezomib, and dexamethasone alone (RVd) (42.4% vs 32.0%). Treatment benefit of D+RVd was further supported by 2-year follow-up data, presented at ASH 2020.

At ASH 2021, updated efficacy and safety results after 24 months of maintenance therapy or treatment discontinuation (median follow-up of 38.6 months) were presented and the rate of sCR was 66% in the D-RVd treatment arm versus 47.4% in the RVd treatment arm. At the time of data collection, median PFS had not been reached in either arm but is trending towards favoring D-RVd versus RVd. The estimated 36-month PFS rate was 88.9% for D-RVd and 81.2% for RVd. Finally, as Dr. Laubach mentions, daratumumab appears to be well-tolerated and no new safety concerns were observed at the 3-year follow-up.