In short
Prexasertib lactate monohydrate is an investigational CHK1 inhibitor being studied in cancer. One authorised Phase 2 trial (NCT05548296) is evaluating it in 375 participants with endometrial cancer, including serous endometrial adenocarcinoma.
Key points
- Phase 2 trial authorised for endometrial cancer
- 375 participants planned for enrollment
- Studies prexasertib alone and with ultra-low-dose gemcitabine
- Primary outcome: confirmed objective response rate (ORR)
- Prexasertib is a CHK1 inhibitor, an investigational cancer drug
What is prexasertib?
Prexasertib lactate monohydrate is an investigational cancer medicine. It belongs to a class of drugs called CHK1 inhibitors. CHK1 is a protein that helps cancer cells survive and repair damage to their DNA. By blocking CHK1, prexasertib makes cancer cells more likely to die.
The substance appears in the EU Clinical Trials Information System under the code ACR-368. In this trial record, prexasertib is the active substance being tested, not a comparator or placebo. It has no marketing authorisation in the data provided, meaning it is still an investigational substance rather than an authorised medicine.
How does prexasertib work?
Prexasertib blocks the CHK1 protein. CHK1 is involved in the DNA damage response, a system cells use to repair their genetic material. Many cancer cells rely heavily on CHK1 to survive. When CHK1 is blocked, cancer cells cannot repair DNA damage effectively and may die.
Research has also looked at whether prexasertib can affect the immune system's ability to fight tumours. A published study examined prexasertib together with an anti-PD-L1 antibody in patients with high-grade serous ovarian cancer and other solid tumours.
Which conditions is prexasertib studied for?
- Endometrial cancer — the authorised Phase 2 trial NCT05548296 focuses on this cancer, including serous endometrial adenocarcinoma.
- High-grade serous ovarian cancer — a published study investigated prexasertib in this condition together with an anti-PD-L1 antibody.
- Other solid tumours — the same published study also included patients with other solid tumours.
How is prexasertib given?
In the authorised Phase 2 trial, prexasertib is given as an intravenous infusion. The dose reported in the trial record is 105 mg per square metre of body surface area.
What do the clinical trials show?
One authorised Phase 2 trial, NCT05548296, is studying prexasertib in endometrial cancer. The trial plans to enroll 375 participants.
The trial has two arms involving prexasertib. One arm assesses the antitumour activity of prexasertib with ultra-low-dose gemcitabine sensitisation in endometrial cancer subjects with serous histology. Another arm assesses prexasertib alone in the same population.
The primary outcome is confirmed objective response rate (ORR), meaning the proportion of participants whose tumours shrink or disappear, measured according to RECIST v1.1 criteria using CT scan or MRI.
The trial is currently authorised, meaning it has received regulatory approval to proceed. Results have not yet been reported in the registry data.
What side effects are known?
The provided supplementary source does not report specific side effects for prexasertib in detail. It describes the immune modulating activity of prexasertib in combination with an anti-PD-L1 antibody, but does not list adverse events in the extracted content.