Safety, tolerability, and pharmacokinetics of Aurora kinase B inhibitor AZD2811: a phase 1 dose-finding study in patients with advanced solid tumours

BACKGROUND

AZD2811 is a potent, selective Aurora kinase B inhibitor. We report the dose-escalation phase of a first-in-human study assessing nanoparticle-encapsulated AZD2811 in advanced solid tumours.

METHODS

AZD2811 was administered in 12 dose-escalation cohorts (2-h intravenous infusion; 15‒600 mg; 21-/28-day cycles) with granulocyte colony-stimulating factor (G-CSF) at higher doses. The primary objective was determining safety and maximum tolerated/recommended phase 2 dose (RP2D).

RESULTS

Fifty-one patients received AZD2811. Drug exposure was sustained for several days post-dose. The most common AZD2811-related adverse events (AEs) were fatigue (27.3%) at ≤200 mg/cycle and neutropenia (37.9%) at ≥400 mg/cycle. Five patients had dose-limiting toxicities: grade (G)4 decreased neutrophil count (n = 1, 200 mg; Days 1, 4; 28-day cycle); G4 decreased neutrophil count and G3 stomatitis (n = 1 each, both 400 mg; Day 1; 21-day cycle); G3 febrile neutropenia and G3 fatigue (n = 1 each, both 600 mg; Day 1; 21-day cycle +G-CSF). RP2D was 500 mg; Day 1; 21-day cycle with G-CSF on Day 8. Neutropenia/neutrophil count decrease were on-target AEs. Best overall responses were partial response (n = 1, 2.0%) and stable disease (n = 23, 45.1%).

CONCLUSIONS

At RP2D, AZD2811 was tolerable with G-CSF support. Neutropenia was a pharmacodynamic biomarker.

CLINICAL TRIAL REGISTRATION

NCT02579226.

A phase I, open label, multicenter dose escalation study of AZD2811 nanoparticle in patients with advanced solid tumors

3098

Background: Aurora kinase B (AURKB) represents a potential target for therapy in solid and hematological malignancies. AURKB inhibitor AZD1152 (barasertib) was previously investigated in solid tumor pts in a phase I setting. AZD2811-nanoparticle (np) is a novel, encapsulated slow release AURKB inhibitor offering several advantages over AZD1152 (Ashton S et al., Sci Transl Med 2016). We report the completed dose-escalation safety, pharmacokinetics (PK), preliminary activity and defined maximum tolerated dose (MTD) of AZD2811-np in pts with advanced solid tumors (NCT02579226). Methods: Adult pts with advanced solid tumors received AZD2811-np IV on Day 1 (D1) and 4 (D4) Q4 week (wk) in six cohorts 15-200 mg/infusion without the use of g-csf in cycle 1. D1 Q4wk and Q3wk schedules were investigated up to 600 mg/infusion (including cohorts with mandatory g-csf prophylaxis on day 8). A standard 3+3 design was used. PK was assessed in cycle 1. Results: 50 pts were recruited into 12 cohorts. D1, D4 Q4wk schedule: 24 pts (15, 25,38, 50, 100 mg/infusion (n=3/cohort), 200 mg/infusion (n=9)). All cohorts were tolerated. Transient grade 4 neutropenia was observed in 7/9 pts at 200 mg/infusion, including 1 DLT (gr4 > 7 days) D1 Q4wk: 200 mg(n=3) was tolerated. D1 Q3wk: 23 pts were evaluated (200/400 mg (n=3,7), and 400/600/500 mg with mandatory g-csf (n=3/5/6)). 400 mg without g-csf was not tolerated (1 gr3 mucosal inflammation & 1 gr4 neutropenia > 7 days). 600 mg with g-csf was not tolerated (gr3 febrile neutropenia & gr3 fatigue). 25/50 pts experienced AE ≥gr 3 (21 considered AZD2811-np-related, 19 neutropenia-related, no deaths within-DLT period). AZD2811-np caused transient gr1/2 fatigue, nausea, diarrhoea and mucosal inflammation. AZD2811 total blood PK appears dose proportional with a t1/2 of 30-50 hours irrespective of schedule. Released AZD2811 concentrations ~1% of total. 14 pts (28%) had disease stabilisation. 1 prostate ca. pt had a confirmed partial response (PR) (continued tx to 451 days). Conclusions: The MTD for AZD2811-np is 500 mg D1 Q3wk. AZD2811-np is now being investigated in a small cell lung cancer expansion. Clinical trial information: NCT02579226.

A phase I, open-label, first-time-in-patient dose escalation and expansion study to assess the safety, tolerability, and pharmacokinetics of nanoparticle encapsulated Aurora B kinase inhibitor AZD2811 in patients with advanced solid tumours

TPS2608

Background: Aurora kinase B performs key roles in the regulation of the cell cycle and represents a potential target for anticancer therapy. AZD2811, formerly designated AZD1152 hydroxy-quinazoline pyrazole anilide (AZD1152 hQPA), is a potent and selective inhibitor of Aurora B kinase activity and has been incorporated into a polymer nanoparticle carrier for intravenous (IV) administration. The phosphate pro-drug of AZD2811, known as AZD1152 (barasertib), reached Phase II of clinical development as a continuous IV infusion. While promising efficacy was seen with barasertib in elderly acute myeloid leukaemia (AML) patients ( Kantarjian HG et al., Cancer 2013;119:2611-19), continuous intravenous drug delivery precluded subsequent development in this disease setting and there were limited clinical responses in solid tumour patients due to dose-limiting myelotoxicity. AZD2811 nanoparticle has been designed to overcome these issues. Methods: Patients with relapsed advanced solid malignancies with no standard treatments are eligible for the part A dose escalation. Primary endpoint is to determine the maximum tolerated dose of AZD2811 nanoparticle using a 3+3 design. Patients with refractory/relapsed small cell lung cancer (SCLC) will be eligible for the part B expansion, where the safety, PK and anti-tumour activity of AZD2811 nanoparticle will be assessed as monotherapy and in combination with chemotherapy. Study enrolment is ongoing. Clinical trial information: NCT02579226.

A pilot study of treatment of active ulcerative colitis with natalizumab, a humanized monoclonal antibody to alpha-4 integrin

BACKGROUND

Alpha-4 integrins facilitate leucocyte migration across vascular endothelium.

AIM

To assess the safety and efficacy of natalizumab (Antegren), a humanized antibody to alpha-4 integrin, in patients with active ulcerative colitis.

METHODS

Ten patients with active ulcerative colitis, defined by a Powell-Tuck activity score > 4, received a single 3 mg/kg natalizumab infusion. The primary end-point was the change in Powell-Tuck score at 2 weeks post-infusion.

RESULTS

Significant decreases in the median Powell-Tuck score were observed at 2 and 4 weeks post-infusion (7.5 and 6, respectively) compared to the median baseline score (10). Five of 10 patients achieved a good clinical response at 2 weeks and one more patient by 4 weeks, defined by a Powell-Tuck score of < or = 5. Significant improvements in quality of life scores were found at week 4. Rescue medication was required by two (20%), three (30%) and eight (80%) patients by weeks 2, 4 and 8, respectively (median, 34 days; range, 8-43 days). One patient remained in remission at 12 weeks. The median C-reactive protein at 2 weeks (6 mg/L) was lower than that pre-treatment (16 mg/L).

CONCLUSIONS

A single 3 mg/kg infusion of natalizumab was well tolerated by ulcerative colitis patients. The positive efficacy demonstrated in this study merits further investigation by randomized, placebo-controlled trials.

A randomized placebo-controlled trial of a humanized monoclonal antibody to alpha4 integrin in active Crohn's disease

BACKGROUND & AIMS

alpha4 integrins are important mediators of leukocyte migration across vascular endothelium. This pilot placebo-controlled study aimed to assess the safety and efficacy of natalizumab, a recombinant humanized monoclonal antibody to alpha4 integrin, in patients with mild to moderately active Crohn's disease.

METHODS

Thirty patients with active Crohn's disease (Crohn's Disease Activity Index [CDAI] > or =151 and < or =450) received a 3-mg/kg infusion of natalizumab (n = 18) or placebo (n = 12) by double-blind randomization. The study's primary endpoint was change in CDAI at week 2.

RESULTS

At week 2, the CDAI decreased significantly from baseline after infusion of natalizumab (mean 45 points) but not placebo (mean 11 points). Seven (39%) natalizumab-treated patients achieved remission at week 2, compared with 1 (8%) treated with placebo. In contrast, 4 (33%) of the placebo-treated patients required rescue medication by week 2, compared with 2 (11%) natalizumab-treated patients. Significant increases in circulating B and T lymphocytes were detected only after natalizumab administration. The frequency of commonly reported adverse events did not differ significantly between groups.

CONCLUSIONS

A single 3-mg/kg natalizumab infusion was well tolerated by Crohn's disease patients, although the dose used may have been suboptimal. Elevated circulating lymphocyte levels after natalizumab suggest interrupted lymphocyte trafficking. Natalizumab therapy in active Crohn's disease merits further investigation.

Drugs in development for the treatment of multiple sclerosis: antigen non-specific therapies--an update

In the past few years there has been significant progress in the development of therapy for the treatment of relapsing remitting and secondary progressive multiple sclerosis. Research interest in multiple sclerosis (MS) therapeutics has remained high and clinical investigation into potential new therapies continues. This review summarises the advances with currently available therapies and briefly outlines the results from studies with other drugs being developed for the treatment of multiple sclerosis.

The effects of L-arginine on neointimal formation and vascular function following balloon injury in heritable hyperlipidaemic rabbits

OBJECTIVE

The aims of this study were to determine the morphological and functional consequences of balloon angioplasty of the left subclavian artery of Froxfield heritable hyperlipidaemic (FHHL) rabbits and the influence of oral L-arginine therapy on these changes.

METHODS

Sixteen-week-old FHHL rabbits were subjected to balloon injury of the left subclavian artery under halothane anaesthesia. Control rabbits (n = 7) were given free access to food and normal tap water. L-Arginine-treated rabbits were given L-arginine (5 g.l-1 in the drinking water for 2 days prior to angioplasty and then for either 2 weeks (n = 7) or 4 weeks (n = 7) after surgery. All rabbits were euthanised 28-30 days after surgery and blood and tissue removed for quantification of neointimal size and determination of endothelial function using isolated vessel tension studies. The ability of the endothelium to prevent platelet aggregation was determined by challenging a vessel ring with carbachol when incorporated into a whole blood sample in which platelet aggregation was induced with collagen.

RESULTS

Balloon injury in non-treated rabbits resulted in the development of marked intimal hyperplasia (18.8[3.6]% of the area within the internal elastic lamina) while endothelial function remained intact. Maximum responses to carbachol and calcimycin were, respectively, a 66.6[14.7]% and 46.9[12.9]% relaxation of 5HT-induced tone, compared to 58.0[3.2]% and 39.8[9.4]% in non-injured vessels. Maximum contractile responses to 5HT and KCl were unaffected by injury. L-Arginine therapy alone had no effect on the vasodilator function of the endothelium, but reduced the endothelium-dependent inhibition of platelet aggregation (68.4[7.8] vs 109[10]% of the maximum extent of platelet aggregation in non-treated and 2-week L-arginine-treated non-injured vessels, respectively). L-Arginine significantly reduced the extent of neointimal formation (7.2[3.9]% of the area within the IEL; P < 0.05 vs. non-treated group). However, L-arginine significantly attenuated the relaxant responses to both carbachol (26.5[10.4]% and 31.4[9.4]% for 2- and 4-week L-arginine groups) and calcimycin (38.7[15.4]% and 16.4[10.7]%) in the injured artery (P < 0.05 compared to non-treated controls).

CONCLUSIONS

L-Arginine reduces neointimal formation following balloon catheter injury in heritable hypercholesterolaemic rabbits, which is consistent with previous findings in normocholesterolaemic models. However, in the presence of hypercholesterolaemia, L-arginine has a detrimental effect on endothelial function following injury. This may be a consequence of the presence of lipids in the vascular wall on nitric oxide synthase activity.

Vasorelaxant and antiaggregatory properties of the endothelium: a comparative study in normocholesterolaemic and hereditary and dietary hypercholesterolaemic rabbits

1. A comparison of the effects of dietary and genetically-induced hypercholesterolaemia on the vasodilator and antiaggregatory capacity of the endothelium was made in rabbit isolated subclavian artery rings. 2. Dietary-induced hypercholesterolaemia in NZW rabbits decreased the maximum relaxation to carbachol (0.01-10 microM) and calcimycin (0.01-0.1 microM) in vessel rings precontracted with 5-hydroxytryptamine (5-HT), 0.1 microM), when compared to responses observed in rings obtained from control normocholesterolaemic NZW rabbits. The relaxant responses to SIN-1 (3-(4-morpholinyl)-sydnonimine hydrochloride) were attenuated but were not significantly different from controls. In Froxfield genetically hypercholesterolaemic (FHH) rabbits, the maximum relaxations to carbachol, calcimycin and SIN-1 were all reduced significantly. 3. Neither genetic nor dietary-induced hypercholesterolaemia modified the contractile responses of vessel rings to either KCl (10-100 mM) or 5-HT (0.01-10 microM). 4. Endothelium-dependent inhibition of collagen-induced platelet aggregation in whole blood was demonstrated by stimulation of a vessel ring, incorporated into the blood sample, with carbachol (10 microM, final blood concentration). This effect was inhibited by NG-nitro-L-arginine (L-NOARG, 100 microM). SIN-1 (10 microM, final blood concentration) also decreased whole blood platelet aggregation, but only in the presence of an unstimulated vessel ring, and this was unaffected by L-NOARG. Superoxide dismutase (150 u ml-1) did not influence the inhibition of aggregation by either a carbachol-stimulated vessel ring or by SIN-1. 5. Carbachol-stimulated artery rings from FHH rabbits inhibited platelet aggregation to a similar extent to that seen with rings from control normocholesterolaemic rabbits. Rings from hypercholesterolaemic NZW rabbits, however, did not significantly inhibit platelet aggregation when stimulated with carbachol. SIN-1 inhibited platelet aggregation in the presence of rings from either group of hypercholesterolaemic rabbits. 6. Hypercholesterolaemia induced by dietary modification induces changes in endothelial function which are characteristically different from those seen in genetically hypercholesterolaemic rabbits. It appears that dietary-induced hypercholesterolaemia primarily decreases NO release from the endothelium, while in genetically-induced hypercholesterolaemic vessel rings NO is released but there is a decreased responsiveness of the vascular smooth muscle cells to NO. This may reflect differences in the age and severity of the atherosclerotic lesions in the two groups of rabbits.

Nitric oxide synthase inhibitors 7- and 6-nitroindazole relax smooth muscle in vitro

7-Nitroindazole induced concentration-dependent relaxation of precontracted rabbit aorta, dog middle cerebral artery, rat anococcygeus muscle and rat stomach fundus. Relaxations to 7-nitroindazole in rabbit aorta were unaffected by nitric oxide synthase blockade or endothelial removal. 6-Nitroindazole also caused concentration-dependent relaxation in dog middle cerebral artery and rabbit aorta, being equipotent with 7-nitroindazole in both tissues. These data suggest that indazole derivatives can induce an endothelium- and nitric oxide synthase-independent relaxation of smooth muscle in vitro.