Clinical disposition, metabolism and in vitro drug–drug interaction properties of omadacycline

Figures & data

Figure 1. [¹⁴C]-Omadacycline (asterisk indicates position of ¹⁴C label).

Figure 2. Incubation of [¹⁴C]-omadacycline in human liver microsomes. [¹⁴C]-omadacycline (12 or 48 μM) incubations were conducted in the absence or presence of metabolic co-factors (48 μM incubation results shown). Results shown include: (A) the absence of co-factors, (B) the presence of NADPH, (C) the presence of UDP-glucuronic acid (UPPGA) and (D) presence of NADPH and UDPGA. Incubations using 12 μM [¹⁴C]-omadacycline also showed no evidence for metabolic turnover (not shown).

Figure 3. Incubation of [¹⁴C]-omadacycline in human hepatocytes. Pooled cryopreserved human hepatocytes (1 × 10⁶ cells mL⁻¹) were incubated with [¹⁴C]-omadacycline (2.5 μM and 12.5 μM). The reactions were quenched after 2, 4, 8 or 24 h incubations, by the addition of an equal volume of cold acetonitrile. Incubation mixtures (A, 4 h; B, 24 h) were analyzed by LC with radiochemical detection (12.5 μM results shown).

Table 1. [¹⁴C]-omadacycline permeability across Caco-2 cell monolayers and the effect of transport protein inhibitors^a.

Omadacycline concentration (μM)	Inhibitor concentration (μM)	Transporter	Papp × 10^−5 Ap to BI (cm/min)	Papp × 10^−5 BI to Ap (cm/min)
2.0	None	–	2.73 ± 0.43	35.7 ± 3.7
	LY335979, 1.0	P-gp	7.66 ± 0.56	10.8 ± 1.2
	MK571, 10	MRP2	3.97 ± 0.76	35.1 ± 1.7
	Ko143, 1.0	BCRP	3.71 ± 0.99	36.9 ± 2.3
12	None	–	2.10 ± 0.14	26.6 ± 2.4
	LY335979, 1.0	P-gp	5.80 ± 0.22	7.0 ± 0.3

^aUptake experiments conducted over 120 min at 37 °C.

Table 2. Inhibition of human transporter proteins by omadacycline.

			Mean ± SD substrate accumulation^a (pmol/mg protein)
Transporter	Substrate (μM)	Inhibitor (μM)	HEK-Flp-In	Transfected Cells	% Inhibition
hOAT1	[^3H]-PAH (1.0)	None	6.4 ± 0.3	32.5 ± 1.2	–
		Probenecid (100)	6.4 ± 0.3	7.0 ± 0.5	98.0
		OMC (5.0)	5.9 ± 0.2	27.6 ± 2.6	16.7
		OMC (25.0)	6.0 ± 0.2	23.7 ± 1.9	32.1
hOAT3	[^3H]-E3S (1.0)	None	3.0 ± 0.5	68.2 ± 3.1	–
		Probenecid (100)	3.2 ± 0.4	5.5 ± 0.3	96.5
		OMC (25.0)	3.1 ± 0.3	68.4 ± 0.6	0
OATP1B1	[^3H]-E217βG (1.0)	None	0.78 ± 0.09	25.52 ± 0.67
		Rifamycin SV (25)	0.82 ± 0.03	0.94 ± 0.09	99
		OMC (100)	0.72 ± 0.15	23.12 ± 1.40	9.7
OATP1B3	[^3H]-CCK8 (0.033)	None	0.20 ± 0.01	0.67 ± 0.04	–
		Rifamycin SV (25)	0.18 ± 0.01	0.17 ± 0.01	105
		OMC (100)	0.23 ± 0.01	0.63 ± 0.07	8.5
hOCT2	[^14C]-Metformin (16)	None	2.5 ± 0.2	126.0 ± 2.2	–
		Decynium (22, 20)	1.4 ± 0.5	2.4 ± 0.5	99
		OMC (100)	1.9 ± 0.5	114.0 ± 2.8	9.2

^aCells incubated with substrate ± inhibitor for 5 min (hOAT) or 4 min (hOATP and hOCT) at 370C; OMC, omadacycline; Model substrates, para-aminohippurate (hOAT1), estrone-3-sulfate (hOAT3), estradiol-17β-D-glucuronide (hOATP1B1), cholecystokinin (hOATP1B3) and metformin (hOCT2) performed as expected with and without inhibitors.

Table 3. Induction of mRNA of P-gp and MRP2 by omadacycline.

			Mean ± SD fold change
mRNA	Treatment	Inducer concentration (μM)	Liver 1	Liver 2
P-gp	None	–	1.0	1.0
	Omadacycline	100	1.16 ± 0.34	1.31 ± 0.25
	Rifampicin	10	2.53 ± 0.37	3.13 ± 0.99
MRP2	None	–	1.0	1.0
	Omadacycline	100	0.76 ± 0.23	1.01 ± 0.63
	Rifampicin	10	1.58 ± 0.40	1.48 ± 0.38

Table 4. Induction of mRNA and enzyme activity of various drug-metabolizing enzymes.

			Mean±SD fold change
			mRNA		Activity
mRNA	Treatment^a	Inducer (μM)^b^,^c	Liver 1	Liver 2	Liver 1	Liver 2	Liver 3
CYP1A1	None	–	1.0	1.0	–^d	–	–
	OMC	100	2.97 ± 0.66	2.00 ± 0.93	–	–	–
	RIF	50	3.21 ± 0.90	3.84 ± 0.35	–	–	–
	PB	1000	3.86 ± 0.93	3.97 ± 0.41	–	–	–
	BNF	10	42.0 ± 11	66.6 ± 5.1	–	–	–
CYP1A2	None	–	1.0	1.0	1.0	1.0	1.0
	OMC	100	4.89 ± 1.2	3.25 ± 1.5	1.12 ± 0.14	1.41 ± 0.11	1.04 ± 0.11
	RIF	50	0.926 ± 0.12	0.847 ± 0.15	0.66 ± 0.09	1.36 ± 0.14	1.55 ± 0.16
	PB	1000	4.26 ± 3.3	2.09 ± 0.19	0.83 ± 0.09	1.39 ± 0.13	2.40 ± 0.21
	BNF	10	15.4 ± 4.4	22.4 ± 4.8	2.15 ± 0.24	27.0 ± 2.7	20.1 ± 1.6
CYP1B1	None	–	1.0	1.0	–	–	–
	OMC	100	0.933 ± 0.23	0.636 ± 0.36	–	–	–
	RIF	50	0.692 ± 0.15	0.878 ± 0.16	–	–	–
	PB	1000	1.02 ± 0.32	1.09 ± 0.078	–	–	–
	BNF	10	5.04 ± 1.0	5.04 ± 1.0	–	–	–
CYP2B6	None	–	1.0	1.0	1.0	1.0	1.0
	OMC	100	2.67 ± 0.98	1.43 ± 0.83	0.77 ± 0.05	0.80 ± 0.08	0.85 ± 0.11
	RIF	50	2.80 ± 0.36	4.78 ± 1.1	2.97 ± 0.17	6.65 ± 0.59	5.47 ± 0.72
	PB	1000	10.4 ± 2.3	17.0 ± 1.9	8.99 ± 0.60	7.16 ± 0.83	12.2 ± 1.6
	BNF	10	0.865 ± 0.13	1.72 ± 0.33	0.58 ± 0.048	2.51 ± 0.28	6.35 ± 0.86
CYP2C8	None	–	1.0	1.0	1.0	1.0	1.0
	OMC	100	2.99 ± 0.50	3.97 ± 0.97	1.24 ± 0.14	1.02 ± 0.09	0.75 ± 0.08
	RIF	50	4.42 ± 1.6	3.08 ± 0.31	1.78 ± 0.21	1.62 ± 0.17	2.02 ± 0.24
	PB	1000	4.74 ± 1.2	7.92 ± 1.1	2.62 ± 0.24	1.34 ± 0.15	3.20 ± 0.42
	BNF	10	0.37 ± 0.06	0.49 ± 0.06	0.95 ± 0.08	0.62 ± 0.07	1.40 ± 0.20
CYP2C9	None	–	1.0	1.0	1.0	1.0	1.0
	OMC	100	1.69 ± 0.97	1.11 ± 0.35	1.01 ± 0.13	1.09 ± 0.10	0.44 ± 0.05
	RIF	50	1.83 ± 1.3	2.04 ± 1.4	2.37 ± 0.25	3.36 ± 0.34	2.17 ± 0.29
	PB	1000	1.77 ± 0.35	2.29 ± 0.60	3.17 ± 0.35	3.43 ± 0.39	1.59 ± 0.18
	BNF	10	0.39 ± 0.12	0.45 ± 0.11	1.08 ± 0.12	1.35 ± 0.10	2.11 ± 0.22
CYP2C19	None	–	1.0	1.0	1.0	1.0	1.0
	OMC	100	1.98 ± 0.50	1.50 ± 0.15	1.17 ± 0.10	1.49 ± 0.14	1.04 ± 0.10
	RIF	50	2.97 ± 2.5	1.64 ± 0.29	5.24 ± 0.45	4.49 ± 0.52	5.45 ± 0.58
	PB	1000	3.37 ± 1.3	2.45 ± 0.61	7.68 ± 0.77	2.10 ± 0.21	2.45 ± 0.22
	BNF	10	0.67 ± 0.29	0.56 ± 0.065	1.71 ± 0.13	0.948 ± 0.11	1.96 ± 0.23
CYP2J2	None	–	1.0	1.0	–	–	–
	OMC		1.48 ± 0.32	1.62 ± 0.34	–	–	–
	RIF	50	0.66 ± 0.15	0.758 ± 0.12	–	–	–
	PB	1000	0.77 ± 0.20	0.869 ± 0.12	–	–	–
	BNF	10	0.55 ± 0.20	0.819 ± 0.30	–	–	–
CYP3A4	None	–	1.0	1.0	1.0	1.0	1.0
	OMC	100	1.60 ± 0.24	0.821 ± 0.29	0.765 ± 0.084	0.603 ± 0.061	0.719 ± 0.071
	RIF	50	18.0 ± 2.7	7.84 ± 2.7	9.99 ± 1.0	12.3 ± 1.6	14.7 ± 1.7
	PB	1000	13.6 ± 2.4	10.9 ± 4.4	21.5 ± 2.4	5.90 ± 0.69	10.1 ± 1.2
	BNF	10	0.19 ± 0.08	0.13 ± 0.04	0.947 ± 0.097	0.496 ± 0.059	2.04 ± 0.24
CYP3A5	None	–	1.0	1.0	–	–	–
	OMC	100	1.95 ± 0.85	0.523 ± 0.17	–	–	–
	RIF	50	1.39 ± 0.33	0.267 ± 0.23	–	–	–
	PB	1000	1.86 ± 0.16	0.408 ± 0.11	–	–	–
	BNF	10	0.28 ± 0.08	0.068 ± 0.02	–	–	–
UGT1A1	None	–	1.0	1.0	1.0	1.0	1.0
	OMC	100	1.77 ± 0.36	1.81 ± 0.55	1.21 ± 0.063	1.51 ± 0.17	0.706 ± 0.053
	RIF	50	1.23 ± 0.36	1.49 ± 0.20	1.11 ± 0.057	1.52 ± 0.15	0.500 ± 0.047
	PB	1000	2.21 ± 0.30	2.19 ± 0.47	1.44 ± 0.075	1.33 ± 0.17	0.721 ± 0.051
	BNF	10	1.31 ± 0.37	1.72 ± 0.20	2.43 ± 0.15	2.06 ± 0.27	1.54 ± 0.14

^aOMC, omadacycline; RIF, rifampicin; PB, phenobarbital; BNF, β-naphthoflavone.

^b Omadacycline concentrations were 1, 10, 50 and 100 μM, 100 μM results shown.

^c Rifampicin concentrations were 1, 5, 10, 25 and 50  μM, 50 μM results shown.

^d not determined. However, for CYP1A1 activity since there exists no CYP1A1-selective probe, the phenacetin probe results are reflective of both CYP1A1 and CYP1A2 activities.

Table 5. Pharmacokinetic parameters (mean ± SD) after a single 300 mg oral dose of [¹⁴C]-omadacycline.

Pharmacokinetic parameters	Total blood radioactivity	Total plasma radioactivity	Plasma omadacycline
Tmax (h)^a	2.75 (range 1.5–4)	2 (range 1–3)	2.3 (range 1–4)
Cmax (ng/mL or ngEq/mL)	608 ± 73.6	612 ± 81.5	563 ± 79.5
AUC0-8^b (ng h/mL or ngEq h/mL)	NC^c	3143 ± 804	3019 ± 482
AUClast (ng h/mL or ngEq h/mL)	1867 ± 1322	3096 ± 1548	8573 ± 1941
AUCinf (ng h/mL or ngEq h/mL)	NC	NC	9418 ± 1857
T1/2 (h)	NC	NC	17.6 ± 1.45
CL/F (L/h)	NA	NA	32.8 ± 5.90
Vz/F (L)	NA	NA	828 ± 133

^aMedian (range).

^b Radioactivity only quantifiable up to 8 h due to very low levels.

^c NA/NC, not calculated or not applicable.

Parameters for total blood and plasma radioactivity could not be calculated due to insufficient data because of very low radioactivity (below quantification limit).

Figure 4. Plasma omadacycline concentration-time profiles following a single oral dose of [¹⁴C]-omadacycline. Semilog plot is shown to illustrate biphasic kinetics.

Figure 5. Mean plasma radioactivity versus omadacycline concentration–time profiles following a single oral dose of [¹⁴C]-omadacycline (plasma radioactivity values were below quantification limit after 8 h).

Figure 6. Cumulative urinary and fecal excretion of radioactivity following a single oral dose of [¹⁴C]-omadacycline.

Table 6. Excretion of total radioactivity (% of dose) in male subjects after a single 300 mg oral dose of [¹⁴C]-omadacycline.

	Subject
	5101	5102	5103	5104	5105	5106	Mean (SD)
Urine total	16.2	14.6	17.4	10.7	14.4	13.3	14.4 (2.33)
Omadacycline	8.28	6.95	8.48	5.10	7.26	7.45
C4-epimer	5.32	5.43	6.81	4.19	4.79	3.75
Feces total	82.1	80.0	77.5	80.1	82.8	84.0	81.1 (2.34)
Omadacycline	34.9	42.8	39.4	38.4	39.5	39.7
C4-epimer	28.2	28.1	27.9	34.5	33.1	33.4
Total in excreta	98.3	94.6	94.9	90.8	97.2	97.3	95.5 (2.73)

Figure 7. Representative radio-profiles in human (A) urine and (B) feces, after a single oral 300 mg dose of [¹⁴C]-omadacycline. Results shown reflect pooled samples from time intervals representing ∼94% of urinary radioactivity (Subject 5103) and ∼96% of fecal radioactivity (Subject 5101).

Table 7. Structures of omadacycline and related components in male subjects following a single oral dose of 300 mg [¹⁴C]-omadacycline.

Peak ID	Exact mass MH^+	Measured mass MH^+	Mass Error (ppm)	Matrix	Proposed structures
Omadacycline	557.2970	557.2976	1.120	PlasmaUrineFeces (Dose)
C4-epimer	557.2970	557.2975	0.940	UrineFeces (Dose)
Minor or trace components^a
Impurity 2	571.3126	571.3127	0.129	UrineFeces (Dose)
4-keto	528.2340	528.2339	−0.179	UrineFeces (Dose)
M-2 impurity	555.2813	555.2799	−2.568	UrineFeces (Dose)
Omadacycline Degradation-1	557.2970	557.2969	−0.179	UrineFeces (Dose)	ND^b
Omadacycline Degradation-2	557.2970	557.2964	−1.077	UrineFeces (Dose)	ND
P26.8	573.2924	573.2932	1.395	Urine (Dose)
P28.3	573.2924	573.2914	−1.744	Urine (Dose)
P35.8	543.2819	543.2816	−0.552	Feces (Dose)

^aMinor or trace, each <1% of dose; ^bND, structure not defined