A CRUK First-in-human Phase I Trial of LY3143921, a Novel CDC7 Inhibitor, in OPatients with Advanced Solid Tumors

Gallagher, P. F. et al. (2022) A CRUK First-in-human Phase I Trial of LY3143921, a Novel CDC7 Inhibitor, in OPatients with Advanced Solid Tumors. 2022 ASCO Annual Meeting I, 03-07 Jun 2022. p. 3103. (doi: 10.1200/JCO.2022.40.16_suppl.3103)

Abstract

Background: CDC7, a protein with key roles in regulating cell-cycle progression is often over-expressed in malignant cells, particularly those with TP53 mutations. LY3143921, an orally administered ATP-competitive CDC7 inhibitor, demonstrated favorable pre-clinical anti-cancer activity in colorectal cancer (CRC) and squamous non-small cell lung cancer (sqNSCLC), particularly in TP53 mutant models. Methods: Phase Ia (dose escalation) recruited patients (pts) with advanced solid tumors enriched for malignancies associated with TP53 mutation. Pts received LY3143921 OD or BD continuously on a 21-day schedule, using an accelerated 3+3 escalation design, starting at 30 mg OD. Phase Ib recruited pts with CRC or sqNSCLC treated continuously at RP2D, or pts with other advanced tumors treated at RP2D on days 1-3 every 7 days. Radiological assessment was performed every 2 cycles initially. Pts in phase Ib could consent to pre- and on-treatment skin +/- tumor biopsies. Primary objectives: assess safety/tolerability and determine MTD and RP2D of LY3143921. Secondary objectives: evaluate preliminary efficacy and pharmacokinetic (PK) profile of LY3143921. Exploratory objective: correlate efficacy to baseline molecular/genetic alterations, including TP53 mutation and measure markers including pMCM2 in pre- and on- treatment tumor and skin samples. Results: 68 pts were recruited and 67 treated (38 phase Ia, 29 phase Ib). Most frequent drug-related CTCAEs (all grades): nausea (75%), orthostatic hypotension (50%), vomiting (47%), fatigue (45%) & diarrhea (44%). Grade 3-4 LY3143921 related AEs occurred in 17 pts. In phase Ia 8 DLTs occurred in 5 pts (G3 nausea, vomiting, fatigue & hyponatraemia and G2 diarrhea, anorexia & lethargy). RP2D was 360 mg BD (continuous non-fasted dosing schedule). 37 pts were evaluable for radiological response with no complete or partial responses seen, and stable disease (SD) was observed in 24 pts (65%). In phase Ia 3 pts achieved long term SD of 1, 2.5 and 3+ years duration. For evaluable pts treated in phase Ib, SD was seen in 8/12 CRC pts, 1/2 sqNSCLC pts and 2/2 pts treated with the intermittent schedule (median duration 15 weeks, range 6-18+). 2 pts remain on-study. Recruitment ceased due to lack of radiological response according to RECIST. Dose-dependent increases in LY3143921 exposure (Cmax & AUC0-24) were seen. IHC analyses of skin biopsies demonstrated reductions in pMCM2, indicating on-target activity of LY3143921. Pre-clinical testing of combination with standard of care agents is ongoing. Additional PD and PK data will be presented. Conclusions: LY3143921 is well tolerated, exhibits dose-dependent increases in plasma exposure and demonstrates evidence of target inhibition. Significant monotherapy clinical activity was not observed; further analyses should investigate potential predictive response biomarkers and rational combination approaches. Clinical trial information: NCT03096054.

• Item Type: Conference or Workshop Item
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Yalla, Dr Krishna
• Authors: Gallagher, P. F., Naylor, G., Bashir, S., Yan, X., Burke, D., Plummer, E. R., Evans, T.R. J., Coyle, V. M., Clive, S., McGuigan, L., Heinzmann, K., Halbert, G., Veal, G., Tiplady, E., Barnett, S., Yalla, K., Brook, S., Dobbs, N., and Wilson, R. H.
• College/School: College of Medical Veterinary and Life Sciences > School of Cancer Sciences
• Journal Name: Journal of Clinical Oncology