Промежуточные результаты российского проспективного многоцентрового клинического исследования READIT-2020 (снижение дозы ингибиторов тирозинкиназ при ХМЛ, концентрация иматиниба/нилотиниба в плазме, сохранение молекулярного ответа, лекарственная токсичность)
Authors: Гурьянова Маргарита Анатольевна , Казей В. И. , Шухов О. А. , Челышева Е. Ю. , Никифорова А. Г. , Соболев П. Д. , Долов М. С. , Гребенкин Д. Ю. , Петрова А. Н. , Быкова А. В. , Немченко И. С. , Кузьмина Е. А. , Гаврилова Л. В. , Кохно А. В. , Туркина А. Г. 
Published: December 2024

AIM. To measure the trough and maximum plasma concentrations of tyrosine kinase inhibitors (TKIs) in chronic myeloid leukemia (CML) patients on standard and reduced doses of the drugs, to evaluate the impact of TKI plasma concentration on the loss of major/deep molecular response (MR) after dose reduction and the impact of TKI plasma concentration on drug toxicity changes.
MATERIALS & METHODS. The trial enrolled 46 imatinib and 16 nilotinib recipients. The trough (Сtrough) and maximum (Cmax) TKI plasma concentrations were measured. On imatinib/nilotinib therapy, Ctrough was analyzed in 104/22 and Cmax was analyzed in 63/15 plasma samples, respectively.
RESULTS. The mean plasma imatinib Ctrough values on daily 400 mg, 300 mg, and 200 mg of the drug were 1092 ± 346 ng/mL, 809.5 ± 313.0 ng/mL, and 570.9 ± 280.0 ng/mL, respectively. The mean plasma imatinib Cmax on daily 300 mg and 200 mg were 1944 ± 577 ng/mL and 1233.4 ± 44.0 ng/mL, respectively. In the group of patients without deep MR-loss, on daily 300 mg and 200 mg imatinib, the mean plasma Ctrough values were 773.5 ± 303.0 ng/mL and 586.3 ± 308.0 ng/mL, and the mean Cmax values were 1866.5 ± 532.0 ng/mL and 1283.7 ± 481.0 ng/mL, respectively. In the group of patients with deep MR-loss, on daily 300 mg and 200 mg imatinib, the mean plasma Ctrough values were 774.8 ± 553.0 ng/mL and 490.6 ± 175.0 ng/mL, and the mean Cmax values were 2246 ± 1171 ng/mL and 1124.7 ± 281.0 ng/mL, respectively (p > 0.05). The mean plasma imatinib Ctrough values on daily 400 mg, 300 mg, and 200 mg of the drug in the group of patients with drug toxicity were 1120.6 ± 303.0 ng/mL, whereas in the group without adverse effects these values were 998.4 ± 402.0 ng/mL (p = 0.09). The mean nilotinib Ctrough values on daily 600 mg, 400 mg, and 200 mg were 651.4 ± 397.0 ng/mL, 468.7 ± 220.0 ng/mL, and 376.7 ± 151.0 ng/mL, respectively. The mean nilotinib Cmax values on daily 400 mg and 200 mg were 655.3 ± 189.0 ng/mL and 628 ± 293 ng/mL, respectively.
CONCLUSION. This clinical trial yielded differences in plasma imatinib Ctrough and Cmax values in CML patients treated with standard and reduced doses of the drug, which turned out to be significant (p < 0.05). No significant differences in plasma nilotinib Ctrough and Cmax were identified. This trial revealed no significant differences in plasma imatinib Ctrough and Cmax on daily 400 mg and 300 mg of the drug in the groups of patients with and without adverse events. However, while dividing plasma imatinib Ctrough values during the period of 400 mg per day administration into 4 quartiles (Q1 and Q4 included patients with the lowest and the highest Ctrough values, respectively), the proportion of patients with drug toxicity appeared to be the highest in Q4 and accounted for 90 %.