The PVX-410 vaccine with or without lenalidomide is safe and elicits immunogenic responses among patients with smoldering multiple myeloma (SMM), according to a study published in JAMA Oncology.

Previous studies have suggested that the progression of SMM to symptomatic multiple myeloma (MM) may be mediated by the immune system; reinforcing the immune system with a the PVX-410 vaccine may prevent or slow progression to MM. Co-administration with lenalidomide may further enhance an immune response.

For this phase 1/2a study, researchers administered 6 doses of PVX-410 with or without lenalidomide 25 mg to 22 asymptomatic patients with SMM. Study patients were human leukocyte antigen A2-positive, and were considered to be at a moderate- to high-risk of progression to MM.

Results showed that 19 of the 20 evaluable patients had an immune response to PVX-410 alone or with lenalidomide, but patients who received the combination had a greater percentage increase of tetramer-positive cells and interferon γ–positive cells in the CD3+CD8+ cell population. The combination led to significantly greater mean-fold increases after 2 and 4 vaccinations.

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Of the 12 patients who received PVX-410 alone, all patients achieved stable disease (SD) as best response, but 5 patients progressed to MM within 12 months of follow up. Of the 9 patients in the combination group, 1 patient had a partial response, 4 patients had a minimal response, and 4 patients achieved SD.

The most frequently observed treatment-emergent adverse events (AE) included mild-to-moderate injection site reactions, and constitutional symptoms including chills, fatigue, myalgia, and pyrexia. The AE profile of monotherapy and combination therapy were comparable, but those assigned to the combination arm experienced a higher rate and grade of AEs.

The authors concluded that “further study of the vaccine is warranted, including in combination with other agents and for longer durations. The percentage of patients experiencing a myeloma-defining event may be correlated with immune responses in SMM using this vaccination approach.”

Reference

Nooka AK, Wang M, Yee AJ, et al. Assessment of safety and immunogenicity of PVX-410 vaccine with or without lenalidomide in patients with smoldering multiple myeloma [published online August 16, 2018]. JAMA Oncol. doi: 10.1001/jamaoncol.2018.3267

This article originally appeared on ONA