Influence of physiochemical properties on the subcutaneous absorption and bioavailability of monoclonal antibodies

Figures & data

Table 1. General description of the mAbs^a

Platform	mAb	mAb isotype	Charge-based interaction potential	Hydrophobic-based interaction potential	Tagg^b	TMDD In rats^c	TMDD in cynomolgus monkeys^c
1	1P	IgG1	+++	-	-	-	-
	1RE	IgG1	++	-	-	-	-
2	2P	IgG4	++++++++	++	++	-	+
	2RE	IgG4	++++	++	+	-	+
3	3P	IgG4	++	+++	++	-	-
	3RE	IgG4	+	+	-	-	-

^aAll the molecules are humanized IgGs. The ‘+’ and ‘-‘signs indicate the presence and absence of a characteristic, respectively. The number of ‘+’ symbols within the charge- and hydrophobic-based interaction potential columns are intended to provide a qualitative perspective of the relative preponderance of each characteristic across and within the mAb platforms. Quantitative values for the charge- and hydrophobic-based interaction potential are in Table 2. ^bT_agg is the temperature of aggregation onset. ^cTMDD = target-mediated drug disposition.

Table 2. Biophysical and FcRn binding properties of the mAbs^a

Platform	mAb	FcRn Kd (nM) at pH 6	HpnIP (%)	HIP (%)	Zeta potential (mV)	pI	Tagg (^°C)	Tm onset (^°C)	Tm (^°C)
									CH2	CH3	Fab
1	1P	105 ± 5	51.8	1.3	6.2 ± 1.4	8.8	64.2 ± 0.5	61.1	67	83	70
	1RE	98 ± 10	28.3	0.7	9.5 ± 0.2	9.1	64.5 ± 0.2	61.7	70	83	70
2	2P	93 ± 4	100	16.0	10.5 ± 1.4	9.2	52.4 ± 2.1	56.6	69	72	76
	2RE	121 ± 15	58.1	20.1	9.7 ± 1.9	9.5	59.6 ± 1.1	62.0	69	73	76
3	3P	101 ± 7	31.6	100	9.4 ± 0.8	8.3	55.6 ± 2.3	58.9	69	73	68
	3RE	113 ± 4	18.6	11.7	9.7 ± 0.6	8.5	63.9 ± 2.7	62.2	69	73	78

^aFcRn K_d represents cynomolgus monkey FcRn binding affinity at pH 6. Abbreviations: HpnIP, relative heparin-binding interaction potential; HIP, relative hydrophobic interaction potential; pI, isoelectric point; T_agg, temperature of aggregation onset; T_{m onset}, onset of tertiary structure unfolding.

Table 3. Rat pharmacokinetic parameters of the mAbs

Platform	mAb	Route	Dose^ (mg/kg)	Cmax (μg/mL)	Tmax (hr)	AUC0-inf (hr*μg/mL)	CL or CL/F (mL/hr/kg)	T1/2 (hr)	ka^# (1/hr)	%F
1	1P	IV	1	22.4 ± 3.7	NA	1345.5 ± 252.5	0.62 ± 0.22	163 ± 79	NA	NA
		SC	1	5.0 ± 1.0	96 ± 0	1294.9 ± 134.9	0.78 ± 0.08	133 ± 28	0.009 ± 0.001	108 ± 17
	1RE	IV	1	32 ± 3.8	NA	1513 ± 229	0.37 ± 0.03	96 ± 9	NA	NA
		SC	1	10.0 ± 1	64 ± 37	2176 ± 159	0.3 ± 0.1	221 ± 101	0.021 ± 0.012	144 ± 11
2	2P	IV	1	10.6 ± 1.3	NA	210 ± 52	4.5 ± 0.98	117 ± 9	NA	NA
		SC	1	0.2 ± 0	72 ± 72	39 ± 25	6.4 ± 7.0	1375.2 ± 1550.0	0.036 ± 0.006	25 ± 4^a
	2RE	IV	1	21.7 ± 0.8	NA	928 ± 49	0.97 ± 0.07	108 ± 9	NA	NA
		SC	1	3.0 ± 0.3	104 ± 55	564 ± 152	1.5 ± 0.8	158 ± 81	0.012 ± 0.003	61 ± 16
3	3P	IV	1	36.9 ± 1.7	NA	2088 ± 224	0.48 ± 0.06	129 ± 14.2	NA	NA
		SC	1	3.0 ± 1.0	104 ± 60	699 ± 168	0.1 ± 0.2	210 ± 62	0.038 ± 0.016	33 ± 8
	3RE	IV	1	47.5 ± 6.8	NA	3200 ± 121	0.21 ± 0.04	174 ± 21	NA	NA
		SC	1	9.5 ± 1.0	120 ± 0	1816 ± 490	0.5 ± 0.2	154 ± 32	0.013 ± 0.004	57 ± 17

C_max, maximal observed serum concentration; T_max, time of maximal observed serum concentration; AUC_0-inf, area under the serum concentration curve from time zero extrapolated to infinite time; CL, clearance following IV administration; CL/F, apparent clearance as a function of bioavailability following SC administration; T_1/2, elimination half-life; ka, rate of SC absorption; %F, SC bioavailability. All PK parameters were determined from non-compartmental pharmacokinetic analyses unless otherwise noted.

^aDetermined from two compartment pharmacokinetic analyses.

NA = not applicable. ^N = 3/timepoint with serial sampling unless otherwise noted. N = 2 for %F reporting only (standard deviation for illustrative purposes only).

Table 4. Cynomolgus monkey pharmacokinetic parameters of the mAbs

Platform	mAb	Route	Dose^ (mg/kg)	Cmax (μg/mL)	Tmax (hr)	AUC0-∞ (hr*μg/mL)	CL or CL/F (mL/hr/kg)	T1/2 (hr)	ka^#(1/hr)	%F
1	1P	IV	1	24.0 ± 0.6	NA	2910 ± 587	0.35 ± 0.08	278 ± 76	NA	NA
		SC	1	4.0 ± 0.7	48 ± 24	1492 ± 201	0.68 ± 0.10	248 ± 23	0.033 ± 0.006	51 ± 7
	1RE	IV	1	26.9 ± 2.4	NA	4264 ± 1242	0.25 ± 0.06	382 ± 162	NA	NA
		SC	1	12.6 ± 2.6	24 ± 0	3187 ± 111	0.31 ± 0.01	235 ± 53	0.021 ± 0.003	75 ± 3
3	3P	IV	1	27 ± 1.3	0.17 ± 0.12	1832 ± 231	0.56 ± 0.7	271.8 ± 55.9	NA	NA
		SC	1	3.4 ± 1.3	60 ± 17	837 ± 452	1.4 ± 0.8	214.5 ± 102.9	0.094 ± 0.002	46 ± 6
	3RE	IV	1	25.54 ± 3.6	NA	3473 ± 2048	0.35 ± 0.21	213.2 ± 141.2	NA	NA
		SC	1	7.92 ± 0.4	132 ± 50.9	3907 ± 2406	0.32 ± 0.19	337.8 ± 48.2	0.049 ± 0.003	100^a ± 8

C_max, maximal observed serum concentration; T_max, time of maximal observed serum concentration; AUC_0-∞, area under the serum concentration curve from time zero extrapolated to infinite time; CL, clearance following IV administration; CL/F, apparent clearance as a function of bioavailability following SC administration; T_1/2, elimination half-life; k_a, rate of SC absorption; %F, SC bioavailability. NA = not applicable. ^N = 3 cynomolgus monkeys/time point. All PK parameters were determined from non-compartmental pharmacokinetic analyses unless otherwise noted.

^aDetermined from two compartment pharmacokinetic analyses.

Figure 1. Subcutaneous tissue association of the Platform 1 and 3 parent and re-engineered molecules following a single administration of 0.1 mg/kg of each ¹²⁵I labeled mAb. Data show the relative SC tissue association of each re-engineered mAb relative to their respective parental mAb. The 1-h post dose time point skin punctures radioactive count for each mAb was considered 100% bound for data normalization purposes. The 6-h post dose collected radioactivity data were compared reported as a fraction of the percent bound relative to the 1-h post dose time point for calculation, data processing and loss of mAb from the SC site reporting over time. Data are the average of two independent SC tissue assessment from two cynomolgus monkeys for each mAb.

Table 5. Correlation scores for the relationship of the physiochemical parameters with the PK of the mAbs assessed following a single IV administration to rats^a

	PK parameter
Physiochemical parameter	IV Cmax	IV AUC0-∞	IV clearance	IV T1/2
HpnIP	High	High	High	Low
HIP	High	High	High	Low
Tagg	Low	Low	Medium	Medium
Tm onset	Low	Low	Medium	Low

^aCorrelation score rankings of high, medium, and low are defined by data from the determination of the correlation coefficient values (r²) derived from the linear regression best line fit of each physiochemical parameter with each PK parameter. High r² values ranged from 0.71- to 1.0. Medium r² values ranged from 0.51 to 0.70. Low r² values were <0.50.

Table 6. Correlation scores for the relationship of the physiochemical parameters with the PK of the mAbs assessed following a single SC administration to rats^a

	PK parameter
Physiochemical parameter	SC Cmax	SC Tmax	SC AUC0-∞	SC CL/F	SC T1/2	SC ka	SC %F
HpnIP	Medium	Low	Medium	High	Medium	Low	Low
HIP	Medium	Low	Medium	High	Medium	Low	Low
Tagg	High	Low	High	Medium	Medium	Medium	Medium
Tm onset	Medium	Low	Medium	Medium	Medium	High	Low

^aCorrelation score rankings of high, medium, and low are defined by data from the determination of the correlation coefficient values (r²) derived from the linear regression best line fit of each physiochemical parameter with each PK parameter. High r² values ranged from 0.71- to 1.0. Medium r² values ranged from 0.51 to 0.70. Low r² values were <0.50.

Table 7. Correlation scores for the relationship of the physiochemical parameters with the PK of the mAbs assessed following a single IV administration to cynomolgus monkeys^a

	PK parameter
Physiochemical parameter	IV Cmax	IV AUC0-∞	IV clearance	IV T1/2
HpnIP	Medium	Low	Low	Low
HIP	Medium	Low	Low	Low
Tagg	Low	High	High	Low
Tm onset	Low	High	High	Low

^aCorrelation score rankings of high, medium, and low are defined by data from the determination of the correlation coefficient values (r²) derived from the linear regression best line fit of each physiochemical parameter with each PK parameter. High r² values ranged from 0.71- to 1.0. Medium r² values ranged from 0.51 to 0.70. Low r² values were <0.50.

Table 8. Correlation scores for the relationship of the physiochemical parameters with the PK of the mAbs assessed following a single SC administration to cynomolgus monkeys^a

	PK parameter
Physiochemical parameter	SC Cmax	SC Tmax	SC AUC0-∞	SC CL/F	SC T1/2	SC ka	SC %F
HpnIP	Low	Low	Low	Low	Low	Low	Low
HIP	Low	Medium	Low	High	Medium	High	Low
Tagg	Medium	Low	High	High	Low	High	Medium
Tm onset	Medium	Low	High	High	Medium	Medium	High

^aCorrelation score rankings of high, medium and low are defined by data from the determination of the correlation coefficient values (r²) derived from the linear regression best line fit of each physiochemical parameter with each PK parameter. High r² values ranged from 0.71- to 1.0. Medium r² values ranged from 0.51 to 0.70. Low r² values were <0.50.

Figure 2. Correlation plots of the rat pharmacokinetic parameters following SC administration of mAbs 1P and 1RE in Platform 1, mAbs 2P and 2RE in Platform 2 and mAbs 3P and 3RE in Platform 3. Correlation plots for the (a) CL/F, (b) SC bioavailability, (c) rate of SC absorption (k_a), (d) C_max and (e) T_max with the physiochemical properties HpnIP, HIP, T_agg and T_{m onset.}

Figure 3. Correlation plots of the cynomolgus monkey pharmacokinetic parameters following SC administration of mAbs 1P and 1RE in Platform 1 and mAbs 3P and 3RE in Platform 3. Correlation plots for the (a) CL/F, (b) SC bioavailability, (c) rate of SC absorption (k_a), (d) C_max and (e) T_max with the physiochemical properties HpnIP, HIP, T_agg and T_{m onset.}