Modulation of CD47-SIRPα innate immune checkpoint axis with Fc-function detuned anti-CD47 therapeutic antibody.

Cluster of differentiation 47 (CD47) is a transmembrane protein ubiquitously expressed on human cells but overexpressed on many different tumor cells. The interaction of CD47 with signal-regulatory protein alpha (SIRPα) triggers a "don't eat me" signal to the macrophage, inhibiting phagocytosis. Thus, overexpression of CD47 enables tumor cells to escape from immune surveillance via the blockade of phagocytic mechanisms. We report here the development and characterization of CC-90002, a humanized anti-CD47 antibody. CC-90002 is unique among previously reported anti-CD47 bivalent antibodies that it does not promote hemagglutination while maintaining high-affinity binding to CD47 and inhibition of the CD47-SIRPα interaction. Studies in a panel of hematological cancer cell lines showed concentration-dependent CC-90002-mediated phagocytosis in acute lymphoblastic leukemia, acute myeloid leukemia (AML), lenalidomide-resistant multiple myeloma (MM) cell lines and AML cells from patients. In vivo studies with MM cell line-derived xenograft models established in immunodeficient mice demonstrated significant dose-dependent antitumor activity of CC-90002. Treatment with CC-90002 significantly prolonged survival in an HL-60-disseminated AML model. Mechanistic studies confirmed the binding of CC-90002 to tumor cells and concomitant recruitment of F4-80 positive macrophages into the tumor and an increase in expression of select chemokines and cytokines of murine origin. Furthermore, the role of macrophages in the CC-90002-mediated antitumor activity was demonstrated by transient depletion of macrophages with liposome-clodronate treatment. In non-human primates, CC-90002 displayed acceptable pharmacokinetic properties and a favorable toxicity profile. These data demonstrate the potential activity of CC-90002 across hematological malignancies and provided basis for clinical studies CC-90002-ST-001 (NCT02367196) and CC-90002-AML-001 (NCT02641002).

Phase 1 study of anti-CD47 monoclonal antibody CC-90002 in patients with relapsed/refractory acute myeloid leukemia and high-risk myelodysplastic syndromes.

CC-90002 is an anti-CD47 antibody that inhibits CD47-SIRPα interaction and enables macrophage-mediated killing of tumor cells in hematological cancer cell lines. In this first clinical, phase 1, dose-escalation and -expansion study (CC-90002-AML-001; NCT02641002), we evaluated CC-90002 in patients with relapsed/refractory acute myeloid leukemia (AML) or high-risk myelodysplastic syndromes (MDS). CC-90002 was administered in escalating doses of 0.1-4.0 mg/kg, using a modified 3 + 3 design. Primary endpoints included dose-limiting toxicities (DLTs), non-tolerated dose (NTD), maximum tolerated dose (MTD), and recommended phase 2 dose. Secondary endpoints included preliminary efficacy, pharmacokinetics, and presence/frequency of anti-drug antibodies (ADAs). Between March 2016 and July 2018, 28 patients were enrolled (24 with AML and 4 with MDS) at 6 sites across the USA. As of July 18, 2018, all patients had discontinued, mainly due to death or progressive disease. The most common treatment-emergent adverse events were diarrhea (46.4%), thrombocytopenia (39.3%), febrile neutropenia (35.7%), and aspartate aminotransferase increase (35.7%). Four patients experienced DLTs (1 patient had grade 4 disseminated intravascular coagulation and grade 5 cerebral hemorrhage, 1 had grade 3 purpura, 1 had grade 4 congestive cardiac failure and grade 5 acute respiratory failure, and another had grade 5 sepsis). The NTD and MTD were not reached. No objective responses occurred. CC-90002 serum exposure was dose-dependent. ADAs were present across all doses, and the proportion of ADA-positive patients in cycle 1 increased over time. Despite no unexpected safety findings, the CC-90002-AML-001 study was discontinued in dose escalation for lack of monotherapy activity and evidence of ADAs. However, as other anti-CD47 agents in clinical trials are showing promising early results for AML and MDS, understanding preclinical and clinical differences between individual agents in this class will be of high importance.

Recommendations from a global cross-company data sharing initiative on the incorporation of recovery phase animals in safety assessment studies to support first-in-human clinical trials.

An international expert group which includes 30 organisations (pharmaceutical companies, contract research organisations, academic institutions and regulatory bodies) has shared data on the use of recovery animals in the assessment of pharmaceutical safety for early development. These data have been used as an evidence-base to make recommendations on the inclusion of recovery animals in toxicology studies to achieve scientific objectives, while reducing animal use. Recovery animals are used in pharmaceutical development to provide information on the potential for a toxic effect to translate into long-term human risk. They are included on toxicology studies to assess whether effects observed during dosing persist or reverse once treatment ends. The group devised a questionnaire to collect information on the use of recovery animals in general regulatory toxicology studies to support first-in-human studies. Questions focused on study design, the rationale behind inclusion or exclusion and the impact this had on internal and regulatory decisions. Data on 137 compounds (including 53 biologicals and 78 small molecules) from 259 studies showed wide variation in where, when and why recovery animals were included. An analysis of individual study and programme design shows that there are opportunities to reduce the use of recovery animals without impacting drug development.

Effects of SCH 486757, a nociceptin-1 receptor agonist, on fertility and reproductive hormone levels in female CRL:CD®[SD] rats.

BACKGROUND: SCH 486757 is a nociceptin-1 receptor agonist that was in development as an antitussive. Studies were conducted to characterize its effects on female fertility and to examine its potential modes of action. METHODS: Female rats were administered up to 20 mg/kg SCH 486757 before/during mating through gestation day (GD) 7; female fertility and embryonic development were assessed on GD 14. In a subsequent study, pregnant rats were dosed up to 50 mg/kg SCH 486757 from GD 0 to 7. Reproductive hormones were assessed on GD 1, 3, 5, and 7, and embryonic development was assessed on GD 14. A subset of dosed dams were allowed to deliver, were subsequently re-mated, and reproductive hormones and fertility were assessed on GD 7 and 14, respectively. To determine the effects of SCH 486757 on nonpregnant rats, doses of up to 50 mg/kg SCH 486757 were administered for 4 days beginning on the day of estrus; reproductive hormones were assessed after the final dose. RESULTS: Female rats administered ≥20 mg/kg SCH 486757 exhibited abnormal estrous cycles; decreased fertility, number of corpora lutea, and implantation sites; and increased pre- and postimplantation loss. In general, administration of SCH486757 was associated with lower luteinizing hormone (LH) progesterone (P4), and estradiol (E2) levels in pregnant rats. These effects on fertility/embryonic development and reproductive hormones exhibited reversibility post dosing. Nonpregnant rats in the 50-mg/kg group exhibited apparent decreases in P4 and E2 levels, with no apparent effects on LH values. CONCLUSIONS: The SCH 486757-related effects on fertility and embryonic development were likely the result of decreases in P4, E2, and/or LH, rather than being due to decreased prolactin levels.

Investigation Into the Role of ERK in Tyrosine Kinase Inhibitor-Induced Neuropathy.

Chemotherapy-induced peripheral neuropathy (CIPN) is a common and debilitating adverse event that can alter patient treatment options and halt candidate drug development. A case study is presented here describing the preclinical and clinical development of CC-90003, a small molecule extracellular signal-regulated kinase (ERK)1/2 inhibitor investigated as an oncology therapy. In a Phase Ia clinical trial, CC-90003 elicited adverse drug-related neuropathy and neurotoxicity that contributed to discontinued development of CC-90003 for oncology therapy. Preclinical evaluation of CC-90003 in dogs revealed clinical signs and electrophysiological changes consistent with peripheral neuropathy that was reversible. Mice did not exhibit signs of neuropathy upon daily dosing with CC-90003, supporting that rodents generally poorly predict CIPN. We sought to investigate the mechanism of CC-90003-induced peripheral neuropathy using a phenotypic in vitro assay. Translating preclinical neuropathy findings to humans proves challenging as no robust in vitro models of CIPN exist. An approach was taken to examine the influence of CIPN-associated drugs on human-induced pluripotent stem cell-derived peripheral neuron (hiPSC-PN) electrophysiology on multielectrode arrays (MEAs). The MEA assay with hiPSC-PNs was sensitive to CIPN-associated drugs cisplatin, sunitinib, colchicine, and importantly, to CC-90003 in concordance with clinical neuropathy incidence. Biochemical data together with in vitro MEA data for CC-90003 and 12 of its structural analogs, all having similar ERK inhibitory activity, revealed that CC-90003 disrupted in vitro neuronal electrophysiology likely via on-target ERK inhibition combined with off-target kinase inhibition and translocator protein inhibition. This approach could prove useful for assessing CIPN risk and interrogating mechanisms of drug-induced neuropathy.

Assessment of hydroxypropyl methylcellulose, propylene glycol, polysorbate 80, and hydroxypropyl-ß-cyclodextrin for use in developmental and reproductive toxicology studies.

BACKGROUND: A series of studies were conducted to assess Polysorbate 80 (PS80), Propylene Glycol (PG), and Hydroxypropyl-ß-Cyclodextrin (HPßCD), when compared with Hydroxypropyl Methylcellulose (MC) in developmental and reproductive toxicology (DART) studies. METHODS: In the rat fertility study, 20 mg/kg MC, 10 mg/kg PS80, 1,000 mg/kg PG, 500 mg/kg HPßCD or 1,000 mg/kg HPßCD were administered orally before/during mating, and on gestation Day (GD) 0-7, followed by an assessment of embryonic development on GD 14. In the rat and rabbit teratology studies, the doses of MC, PS80, PG, and HPßCD were the same as those in the fertility study. In these teratology studies, pregnant females were dosed during the period of organogenesis, followed by an assessment of fetal external, visceral, and skeletal development. RESULTS: In the rat fertility and rat teratology studies, PS80, PG, and HPßCD did not exhibit toxicity, when compared with MC. Similarly, in the rabbit teratology study, there was no PS80 or PG-related toxicity, when compared with MC. However, individual rabbits in the 500 and 1,000 mg/kg HPßCD groups exhibited maternal toxicity, which included stool findings, decreased food consumption, and body weight gain. Furthermore, one rabbit each in the 500 and 1,000 mg/kg HPßCD groups exhibited evidence of abortion, which was considered secondary to maternal toxicity. CONCLUSIONS: Although HPßCD was not well tolerated in rabbits at doses of 500 and 1,000 mg/kg, PS80 and PG were comparable to MC and should be considered for use in developmental and reproductive toxicology studies.