LITTLE ROCK-High-dose chemotherapy with bone-marrow transplant produces complete remissions in about 40% of multiple myeloma patients, but current maintenance therapy is not able to maintain this response. New preliminary data, however, show that multiple myeloma patients who receive a purified immunoglobulin idiotype protein as a vaccine after high-dose chemotherapy and transplant are likely to have improved event-free survival. Nikhil C. Munshi, MD, of the University of Arkansas for Medical Sciences reported these preliminary results at the ASH meeting.
LITTLE ROCKHigh-dose chemotherapy with bone-marrow transplant produces complete remissions in about 40% of multiple myeloma patients, but current maintenance therapy is not able to maintain this response. New preliminary data, however, show that multiple myeloma patients who receive a purified immunoglobulin idiotype protein as a vaccine after high-dose chemotherapy and transplant are likely to have improved event-free survival. Nikhil C. Munshi, MD, of the University of Arkansas for Medical Sciences reported these preliminary results at the ASH meeting.
A purified Ig protein (0.5 mg) conjugated to keyhole limpet hemocyanian (KLH) as a carrier was used to construct the vaccine. The resulting Id-KLH vaccine was subcutaneously administered together with GM-CSF at the injection site to seven patients who had complete responses and 11 patients who had partial responses following high-dose chemotherapy.
Patients were first vaccinated 3 months after chemotherapy and transplant, when each patient had complete hematopoietic recovery. Each of the first cohort of 18 patients received 3 vaccinations.
All Responded to KLH
Dr. Munshi described clinical results from the first 7 patients treated and immunological responses from all 18 patients. None had pre-vaccination responses to idiotype. After vaccination, 15 of 18 patients had anti-Id-KLH antibody responses; 10 had cytokine responses to idiotype challenge; 13 had cell proliferation responses; and 6 had developed cutaneous hypersensitivity to idiotype. All of those treated responded to KLH, suggesting that their immune systems were intact, Dr. Munshi said.
Median follow-up was 27 months in the 7 patients evaluable for response. Two had partial responses which became complete responses, but since they were vaccinated within 6 months of receiving high-dose chemotherapy, Dr. Munshi said that it was not possible to determine whether this effect was due to the vaccination or to the chemotherapy. Five of the 7 patients are in sustained complete response.
Further Follow-up Needed
Dr. Munshi said that event-free survival was superior in patients who developed idiotype-specific T-cell responses and that the investigators are now trying to determine why some patients develop T-cell responses but others do not.
Multiple myeloma patients are immune competent following autologous transplant. Most can produce an anti-idiotype T-cell response, and a T-cell proliferative response may suggest superior survival, Dr. Munshi concluded. Idiotype vaccination provides significant immunological responses following transplantation, but the clinical benefit requires longer follow-up to evaluate effects on event-free and overall survival.
Relapsed/Refractory Multiple Myeloma Trial Updates From ASCO 2023
August 7th 2023Experts from Mayo Clinic and The University of Texas MD Anderson Cancer Center discuss results from multiple myeloma trials presented at the 2023 American Society of Clinical Oncology Annual Meeting and how they may apply to clinical practice.