adavosertib (AZD1775)

P1, N=13, Active, not recruiting, National Cancer Institute (NCI) | Trial completion date: Sep 2026 --> Dec 2026

P1, N=4, Active, not recruiting, National Cancer Institute (NCI) | Trial completion date: Dec 2025 --> Dec 2026

P2, N=18, Active, not recruiting, National Cancer Institute (NCI) | N=60 --> 18 | Trial completion date: Mar 2026 --> Apr 2027

When tested against TP53-mutated colorectal cancer (CRC) patient-derived organoids (PDOs) grown from peritoneal and liver metastases, 14 exhibited outstanding anticancer efficacy, surpassing previously reported branched alkane counterpart 3, as well as clinical candidates AZD1775 (1) and ZN-c3 (2). Against primary CRC PDOs (TP53-WT, BRAF-V600E, KRAS-WT), 14 profoundly elevated DNA damage and replication stress compared to 1, while amplifying cellular apoptosis, confirming a broadly similar but superior mode of action. Owing to its highly selective and exemplary anticancer efficacy, 14 represents a valuable tool compound for drug testing investigations against primary and metastatic CRCs, especially in the context of PDOs.

In colorectal cancer organoids, 24 outperformed our prior PKMYT1 inhibitor (6), RP-6306, and WEE1 inhibitor AZD1775, with efficacy correlating to improved WEE1 activity. Compound 24 also showed favorable in vitro ADME and early safety profiles, supporting dual checkpoint targeting in checkpoint-deficient cancers.

These findings reveal a novel cytoplasmic function of WEE1 in sustaining MYC stability and chemoresistance. Targeting WEE1 destabilizes MYC and enhances therapeutic response, supporting the combination of MK-1775 and Panobinostat as a promising treatment strategy for EAC.

P2, N=124, Active, not recruiting, National Cancer Institute (NCI) | Trial completion date: Feb 2026 --> Mar 2027

P2, N=273, Active, not recruiting, AstraZeneca | Trial completion date: Dec 2025 --> Sep 2026

P1, N=56, Completed, AstraZeneca | Active, not recruiting --> Completed

In this study, we developed long-term resistant (lt-res, several months) pre-clinical models of two drugs inducing mitotic arrest in TP53-mutated cells: adavosertib (ADA), an investigational WEE1 inhibitor targeting the DNA damage response and currently evaluated in clinical trials, and paclitaxel (PTX), a widely used chemotherapeutic agent in cancer care targeting microtubules. Notably, upregulation of receptor tyrosine kinases, such as ROR1, was observed in both ADA and PTX lt-res models with activated PI3K/AKT signaling. Targeting ROR1 with zilovertamab-vedotin, a monoclonal antibody-drug conjugate, resulted in enhanced cytotoxicity, demonstrating a new approach against recurrent drug-resistant ovarian cancer.

The combination of WEE1 inhibitor adavosertib and vinca alkaloid vincristine demonstrated the highest activity, which was validated in TP53mut SHH-MB patient-derived organoids. Despite the drugs' limited efficacy in the in vivo PDX model, WEE1 knockdown led to significant growth reduction in in vitro and in vivo TP53mut SHH-MB models. Our findings identify WEE1 as a promising target in LFS SHH-MB, suggesting its inhibition combined with vincristine treatment as a potential chemotherapeutic strategy.

Elevated expression of CPSF73 is associated with aggressive disease in prostate cancer patients, and combining JTE-607 with adavosertib synergistically reduced prostate cancer cell survival. Our findings suggest that transcription termination helps prevent toxic conflicts between transcription and replication following increased replication initiation caused by WEE1 inhibition.