Balancing Efficacy and Safety of an Anti-DLL4 Antibody through Pharmacokinetic Modulation

Abstract

Purpose: Although agents targeting Delta-like ligand 4 (DLL4) have shown great promise for angiogenesis-based cancer therapy, findings in recent studies have raised serious safety concerns. To further evaluate the potential for therapeutic targeting of the DLL4 pathway, we pursued a novel strategy to reduce toxicities related to DLL4 inhibition by modulating the pharmacokinetic (PK) properties of an anti-DLL4 antibody.Experimental Design: The F(ab 0 ) 2 fragment of anti-DLL4 antibody (anti-DLL4 F(ab 0 ) 2 ) was generated and assessed in efficacy and toxicity studies.Results: Anti-DLL4 F(ab 0 ) 2 enables greater control over the extent and duration of DLL4 inhibition, such that intermittent dosing of anti-DLL4 F(ab 0 ) 2 can maintain significant antitumor activity while markedly mitigating known toxicities associated with continuous pathway inhibition.Conclusions: PK modulation has potentially broad implications for development of antibody-based therapeutics. Our safety studies with anti-DLL4 F(ab 0 ) 2 also provide new evidence reinforcing the notion that the DLL4 pathway is extremely sensitive to pharmacologic perturbation, further underscoring the importance of exercising caution to safely harness this potent pathway in humans.

Preexisting Antibodies to an F(ab′)2Antibody Therapeutic and Novel Method for Immunogenicity Assessment

“…The titer and anti-CDR methods were used to analyze serum samples from cynomolgus monkeys that were dosed weekly with either vehicle (control group) or 5, 15, or 50 mg/kg anti-DLL4 F(ab′) 2 [ 14 ], with five males and five females in each dose group. Nine doses in total per animal were given over eight weeks.…”

“…Anti-DLL4 F(ab′) 2 was prepared by pepsin cleavage as described in Couch et al [ 14 ]. Anti-DLL4 Fab was prepared by standard papain digestion methods at Genentech.…”

“…Although anti-DLL4 full length antibody showed potent antitumor activity, nonclinical in vivo testing resulted in unmanageable toxicity, with vascular and liver toxicities [ 13 ]. Therefore a rapidly cleared F(ab′) 2 form of a humanized anti-DLL4 monoclonal antibody was generated to ameliorate toxicity while maintaining efficacy [ 14 ] by reducing drug exposure but maintaining sufficient target engagement. During development of an ATA assay for this F(ab′) 2 molecule, we observed a high prevalence of preexisting reactivity to anti-DLL4 F(ab′) 2 in cynomolgus monkey serum samples from drug naïve animals.…”

Interrogation of transcriptomic changes associated with drug-induced hepatic sinusoidal dilatation in colorectal cancer

“…The anti-DLL4 F(ab’) 2 therapeutic binds and blocks human, NHP, and rodent DLL4. Pharmacologic activity of the parental anti-DLL4 mAb (YW152F) and F(ab’) 2 have been characterized [ 14 , 15 ].…”

Safety testing of monoclonal antibodies in non-human primates: Case studies highlighting their impact on human risk assessment

“…Specifically, F(ab') 2 administration was associated with a dose-dependent increase in the incidence and severity of vascular changes in the heart and lung; specifically, endothelial cell proliferation on the right side of the heart, proliferative pulmonary artery mural or adventitial changes (rats only), intimal vacuolation in the pulmonary artery at the base of heart (monkeys only), and increased cellularity of the arteries in the lung (both species). 38 In addition, pulmonary mural basophilia was present in the heart and lungs of both species. After an 8-week recovery period, histopathology findings were reduced in incidence and severity; however, pulmonary arterial adventitial fibrosis was still present.…”