Phase I Study of Ceralasertib (AZD6738), a Novel DNA Damage Repair Agent, in Combination with Weekly Paclitaxel in

Seung Tae Kim1, Simon A Smith2, Peter Mortimer2

  • 1Division of Hematology-Oncology, Department of Medicine, Sungkyunkwan University School of Medicine, Seoul, Korea.

Abstract

Insights

Ceralasertib combined with paclitaxel showed antitumor activity in advanced cancers. Durable responses were seen in melanoma patients resistant to PD1/L1 therapy.

Area of Science:

  • Oncology
  • Pharmacology

Background:

  • Ataxia telangiectasia and Rad3-related (ATR) protein kinase is a key regulator of DNA damage response.
  • Targeting ATR offers a potential therapeutic strategy for various solid tumors.

Purpose of the Study:

  • To evaluate the safety and efficacy of ceralasertib, an ATR inhibitor, in combination with paclitaxel.
  • To determine the recommended Phase 2 dose (RP2D) of ceralasertib plus paclitaxel.

Main Methods:

  • A Phase 1 dose-escalation study using a rolling 6 design.
  • Patients with solid tumors, including melanoma, received escalating doses of ceralasertib with fixed-dose paclitaxel.
  • The study enrolled 57 patients across 7 dose cohorts.

Main Results:

  • The RP2D was determined to be ceralasertib 240 mg BD plus paclitaxel 80 mg/m2.
  • The overall response rate (ORR) was 22.6% in all patients and 33.3% in melanoma patients resistant to prior anti-PD1 therapy.
  • Common toxicities included neutropenia, anemia, and thrombocytopenia.

Conclusions:

  • Ceralasertib plus paclitaxel was well-tolerated and demonstrated antitumor activity in advanced malignancies.
  • Durable responses were observed in patients with advanced melanoma resistant to anti-PD1/L1 therapy, highlighting the potential of ATR inhibition in this population.