Fig. 3 |. BM Chip predicts clinically observed hematotoxicities at patient-relevant drug exposures.

a, BM Chips, suspension cultures, and static gel co-cultures were allowed to mature for 10–12 days and then treated for 48 hours with various doses of 5-FU. Cells were harvested immediately afterwards and analyzed by flow cytometry to quantitate total and neutrophil lineage cells (symbol and error bars represent the mean ± s.d. of n=3–9 BM Chips or wells per concentration, data pooled from 3 independent experiments; numbers indicate P values for static gel [black] and suspension [gray] cultures compared to BM Chips using two-tailed Student’s t-test; ***P < 0.001). The clinical target range of patient plasma 5-FU concentrations for a 2-day infusion is highlighted in orange for reference (exposure levels are known to cause myelosuppression)^29,30. b, BM Chips were created using CD34+ cells from 6 different donors and treated at day 12 with 4μM 5-FU for 2 days. Total cell numbers were quantified at day 14 by flow cytometry (each color represents an individual donor; n=3–4 replicates per donor; error bars, s.d.; ***P < 0.001 using two-tailed Student’s t-test). c, BM Chips were matured for 10 days, treated with 2-hour or 48-hour infusions of AZD2811, and then cultured again in drug-free medium. AZD2811 concentrations were measured by mass spectrometry in BM Chip outlet medium (circles) and used to fit a PK model of BM Chip drug exposure (black line). For reference, in vivo plasma levels of AZD2811 (gray) were simulated for an average patient at a range of clinical doses^35,37 for 2-hour (left) and 48-hour (right) infusions based on the known PK characteristics of AZD2811. Drug levels were below the detection limit (ND = not detectable) at 48 and 96 hours after the start of infusion for the 2-hour and 48-hour regimens, respectively. Dotted line represents the detection limit of mass spectrometry during these experiments (symbol and error bars represent the mean ± s.d. of n=4–8 BM Chips per concentration). d, Graphs showing the effects of infusing the BM Chips on day 10 of culture with varying doses of AZD2811 for 2 hours (left) versus 48 hours (right). Total neutrophil (blue) and erythroid (red) cell numbers were quantified on day 12 by flow cytometry (n=6 chips per condition; error bars, s.d.; data pooled from 2 independent experiments; numbers indicate P values of drug-treated versus control chips using two-tailed Student’s t-test; ***P < 0.001).