Modelling dose and schedule effects of AZD2811 nanoparticles targeting aurora kinase B for treatment of diffuse large B-cell lymphoma

Barasertib (AZD1152), a pro-drug of the highly potent and selective Aurora B kinase inhibitor AZD2811, showed promising clinical activity in relapsed/refractory DLBCL patients administered as a 4-day infusion. To improve potential therapeutic benefit of Aurora B kinase inhibition, a nanoparticle formulation of AZD2811 has been developed to address limitations of repeated intravenous infusion. One of the challenges with the use of nanoparticles for chronic treatment of tumors is optimising dose and schedule required to enable repeat administration to sustain tumor growth inhibition. AZD2811 gives potent cell growth inhibition across a range of DLBCL cells lines in vitro. In vivo, repeat administration of the AZD2811 nanoparticle gave anti-tumor activity at half the dose intensity of AZD1152. Compared to AZD1152, a single dose of AZD2811 nanoparticle gave less reduction in pHH3, but increased apoptosis and reduction of cells in G1 and G2/M, albeit it at later timepoints, suggesting that duration and depth of target inhibition influence the nature of the tumor cell response to drug. Further exploration of the influence of dose and schedule on efficacy revealed that AZD2811 nanoparticle can be used flexibly with repeat administration of 25 mg/kg administered up to 7 days apart being sufficient to maintain equivalent tumor control. Timing of repeat administration could be varied with 50mg/kg every 2 weeks controlling tumor control as effectively as 25mg/kg every week. AZD2811 nanoparticle can be administered with very different doses and schedules to inhibit DLBCL tumor growth, although maximal tumor growth inhibition was achieved with the highest dose intensities.