Serum Alpha-fetoprotein Levels and Clinical Outcomes in the Phase III CELESTIAL Study of Cabozantinib versus Placebo in Patients with Advanced Hepatocellular Carcinoma.

PURPOSE: The phase III CELESTIAL study demonstrated improved overall survival (OS) and progression-free survival (PFS) with cabozantinib versus placebo in patients with previously treated, advanced hepatocellular carcinoma (HCC). We analyzed outcomes by baseline alpha-fetoprotein (AFP) and on-treatment AFP changes. PATIENTS AND METHODS: Serum AFP was measured every 8 weeks by blinded, centralized testing. Outcomes were analyzed by baseline AFP bifurcated at 400 ng/mL and by on-treatment AFP response (≥20% decrease from baseline at Week 8). The optimal cutoff for change in AFP at Week 8 was evaluated using maximally selected rank statistics. RESULTS: Median OS for cabozantinib versus placebo was 13.9 versus 10.3 months [HR, 0.81; 95% confidence interval (CI), 0.62-1.04] for patients with baseline AFP <400 ng/mL, and 8.5 versus 5.2 months (HR, 0.71; 95% CI, 0.54-0.94) for patients with baseline AFP ≥400 ng/mL. Week 8 AFP response rate was 50% for cabozantinib versus 13% for placebo. In the cabozantinib arm, median OS for patients with and without AFP response was 16.1 versus 9.1 months (HR, 0.61; 95% CI, 0.45-0.84). AFP response was independently associated with longer OS. The optimal cutoff for association with OS in the cabozantinib arm was ≤0% change in AFP at Week 8 [AFP control; HR 0.50 (95% CI, 0.35-0.71)]. HRs for PFS were consistent with those for OS. CONCLUSIONS: Cabozantinib improved outcomes versus placebo across a range of baseline AFP levels. On-treatment AFP response and control rates were higher with cabozantinib than placebo, and were associated with longer OS and PFS with cabozantinib.

Outcomes based on prior therapy in the phase 3 METEOR trial of cabozantinib versus everolimus in advanced renal cell carcinoma.

BACKGROUND: In the phase 3 METEOR trial, cabozantinib improved progression-free survival (PFS), objective response rate (ORR), and overall survival (OS) versus everolimus in patients with advanced renal cell carcinoma (RCC), after prior antiangiogenic therapy. METHODS: Outcomes were evaluated for subgroups defined by prior therapy with sunitinib or pazopanib as the only prior VEGFR inhibitor, or prior anti-PD-1/PD-L1 therapy. RESULTS: For the prior sunitinib subgroup (N = 267), median PFS for cabozantinib versus everolimus was 9.1 versus 3.7 months (HR 0.43, 95% CI 0.32-0.59), ORR was 16% versus 3%, and median OS was 21.4 versus 16.5 months (HR 0.66, 95% CI 0.47-0.93). For the prior pazopanib subgroup (N = 171), median PFS for cabozantinib versus everolimus was 7.4 versus 5.1 months (HR 0.67, 95% CI 0.45-0.99), ORR was 19% versus 4%, and median OS was 22.0 versus 17.5 months (HR 0.66, 95% CI 0.42-1.04). For prior anti-PD-1/PD-L1 therapy (N = 32), median PFS was not reached for cabozantinib versus 4.1 months for everolimus (HR 0.22, 95% CI 0.07-0.65), ORR was 22% versus 0%, and median OS was not reached versus 16.3 months (HR 0.56, 95% CI 0.21-1.52). CONCLUSIONS: Cabozantinib was associated with improved clinical outcomes versus everolimus in patients with advanced RCC, irrespective of prior therapy, including checkpoint inhibitor therapy.

Discovery of XL413, a potent and selective CDC7 inhibitor.

CDC7 is a serine/threonine kinase that has been shown to be required for the initiation and maintenance of DNA replication. Up-regulation of CDC7 is detected in multiple tumor cell lines, with inhibition of CDC7 resulting in cell cycle arrest. In this paper, we disclose the discovery of a potent and selective CDC7 inhibitor, XL413 (14), which was advanced into Phase 1 clinical trials. Starting from advanced lead 3, described in a preceding communication, we optimized the CDC7 potency and selectivity to demonstrate in vitro CDC7 dependent cell cycle arrest and in vivo tumor growth inhibition in a Colo-205 xenograft model.

Pyrazolopyrimidines as dual Akt/p70S6K inhibitors.

Activation of the PI3K/Akt/mTOR kinase pathway is frequently associated with human cancer. Selective inhibition of p70S6Kinase, which is the last kinase in the PI3K pathway, is not sufficient for strong tumor growth inhibition and can lead to activation of upstream proteins including Akt through relief of a negative feedback loop. Targeting multiple sites in the PI3K pathway might be beneficial for optimal activity. In this manuscript we report the design of dual Akt/p70S6K inhibitors and the evaluation of the lead compound 11b in vivo, which was eventually advanced into clinical development.

Design and evaluation of a series of pyrazolopyrimidines as p70S6K inhibitors.

The 70-kDa ribosomal protein S6 kinase (p70S6K) is part of the PI3K/AKT/mTOR pathway and has been implicated in cancer. High throughput screening versus p70S6K led to the identification of aminopyrimidine 3a as active inhibitor. Lead optimization of 3a resulted in highly potent, selective, and orally bioavailable pyrazolopyrimidines. In this manuscript we report the structure-activity relationship of this series and pharmacokinetic, pharmacodynamic, and efficacy data of the lead compound 13c.