ID 1 2 3 4 5 6 7 P value∗† ID 1 2 3 4 5 6 7 Mean SD Age 7 12 7 11 8 6 8 Cmax (ng/mL) 23.35 52.06 54.41 57.74 153.57 60.64 19.46 60.18 44.43 Completed Y Y Y Y N N N tmax (h) 1 2 1 1 1 2 1 1.29 0.49 CSF 103 19∗ 101 99 157 232 55 AUCT (ng/mL) 112.35 167.36 179.19 219.72 327.54 281.29 59.39 192.41 92.93 Autism Research and Treatment 5 Table 1: Demographic and TNF-alpha (pg/ml) data for study subjects. Baseline TNF-alpha (pg/ml) Serum ∗1: 1 diluted samples. †P values represent the results of the diﬀerences between baseline values and 6 and 12-month values using the Wilcoxon Signed Ranks Test. Table 2: Parameter estimates for each subject who underwent pharmacokinetic testing at 1, 2, 4, and 8 hours. appear to have potential application in human patients based on these pilot study results. In addition to the number of subjects who completed the study, a limitation of this study included logistical limitations in capturing CSF data at exact baseline and followup, which caused variability in the timeline between these measurements. Due to this we cannot conclude that all the observed changes in CSF levels were due to therapy alone. Pharmacokinetic data was successfully obtained and safety was monitored successfully during the trial. Variability was seen in one patient only in the pharmacokinetic data. Rashes that subsequently recovered were seen on 2 patients. In clinical practice with lenalidomide, rashes are a potential reﬂection of treatment eﬀectiveness and many will continue treatment through a rash but this protocol speciﬁed discontinuation of treatment if a rash occurred. Mild absolute neutrophil count (ANC) decline to <1500 was the cutoﬀ for the FDA safety requirements on this protocol. No hepatic, renal, hematologic or thrombotic changes other than this single ANC event occurred. The results showed a trend towards improvement in language. Three of the seven patients with initial phrase speech were observed by parents and the investigator to show improvement in receptive language and CGI, reﬂecting signiﬁcant levels of change in social and receptive language. These observations were validated through improvements in one-word receptive language testing scores, which showed 74 14∗ 15∗ 102 180 165 58 180 160 )L140 /gm120 n (n100 o i tra 80 t cen 60 onC 40 20 0 Week 12 TNF-alpha (pg/ml) CSF Serum 24 20 5∗ 8∗ 78 54 45 27 106 0.068 0.068 1 001 002 003 004 2 4 8 Hour 005 006 007 Figure 1: Concentration of 2.5 mgs lenalidomide up to eight hours after administration of ﬁrst dose. clinically meaningful changes by 6 weeks of treatment that were measurable yet not statistically signiﬁcant. There were an insuﬃcient number of cases after 12 weeks of followup to compute statistics for expressive and receptive language scores. CARS improved on average greater than 2 points and showed signiﬁcance after 6 weeks. These exploratory outcomes suggest some relationship to treatment were seen, but the small sample size in an open-label study limits conclusions of treatment aﬀect. In addition to the small sample size, this study has several limitations, one of which was the inconsistency with the laboratory processing of TNF-α, as well as the inconsistent timing between CSF samples. There is no consensus on standard laboratory tests that should be analyzed for children with autism. TNF-α and other cytokine measurements are done infrequently so there is no standardization in how these labs are processed. The current lack of commercially standardized TNF values and test protocols somewhat limits exact correlation; however CSF and serum TNF samples were processed in the same manner at baseline and 12