CCL3 and CCL4 serum levels before and during therapy with lenalidomide. CCL3 and CCL4 plasma levels were measured by enzyme-linked immunosorbent assay in peripheral blood samples of patients before therapy and after 3, 9, and 15 cycles of lenalidomide. (A) CCL3 levels (pg/mL) measured before therapy according to NCI response: NR, CR, and PR (mean ± SEM, 102.8 ± 42.6, 53.9 ± 10.5, and 75.6 ± 19.5, respectively) and (B) CCL4 levels (pg/mL) according to response: NR, CR, and PR (mean ± SEM, 411.5 ± 172.9, 261.4 ± 71.1, and 302.0 ± 94, respectively). There was no significant difference in CCL3 or CCL4 levels before therapy between response groups. CCL3 and CCL4 levels were also measured during therapy. (C) Although there was an increase in CCL3 levels by 3 cycles of therapy regardless of response, by 9 cycles of therapy significantly higher levels of CCL3 were noted in nonresponders compared with responders (P < .05). There were insufficient data to assess the difference between responders and nonresponders after 15 cycles of therapy. (D) Similarly, CCL4 levels increased both in responders and nonresponders after 3 cycles of therapy, but there were significantly higher CCL4 levels occurring in responders to therapy after 9 cycles of therapy with lenalidomide (P < .05). Insufficient data were available after 15 cycles of therapy for comparison. NR indicates no response (stable or progressive disease); PR, partial response; CR, complete response; and R, responders (PR or CR).