This article is more than 5 years old. Information may no longer be current.
Vemurafenib decreased lymphocyte counts, altered T-cells in melanoma
Click Here to Manage Email Alerts
Vemurafenib and dabrafenib demonstrated similar efficacy in patients with melanoma, but only vemurafenib treatment was associated with decreased peripheral lymphocyte counts and altered CD4-positive T-cell phenotype and function, according to study results.
Researchers in Germany conducted the study to assess the impact of selective BRAF inhibitors on patients’ immune systems. They pooled data on whole blood counts and serum lactate dehydrogenase for 277 patients with melanoma treated with vemurafenib (Zelboraf, Genentech) and 65 patients treated with dabrafenib (Tafinlar, GlaxoSmithKline).
Patients in both treatment groups demonstrated similar PFS and OS. Also, high levels of serum lactate dehydrogenase prior to treatment were associated with shortened PFS and OS regardless of treatment.
However, only vemurafenib was associated with a decrease in median peripheral lymphocyte count. Median counts decreased by 24.3% (P<.0001) in the vemurafenib arm and increased by 1.2% (P=.0717) in the dabrafenib arm.
Differentiation of peripheral lymphocytes of vemurafenib-treated patients was associated with a significant decrease in CD4-positive T cells (P<.05). Also, secretion of interferon-gamma and interleukin-9 by CD4-positive T cells appeared significantly lower in samples evaluated during vemurafenib treatment compared with samples evaluated at baseline, researchers wrote.
“Selective BRAF inhibitors can significantly affect patients’ peripheral lymphocyte populations,” the researchers concluded. “Fully understanding these effects could be critical for successfully implementing combinatorial therapies of BRAF inhibitors with immunomodulatory agents.”
Disclosure: See the study for a list of the researchers’ relevant financial disclosures.
Click Here to Manage Email Alerts