GLR2037: A First‑in‑Human AR‑Targeted PROTAC Enters Phase 1 Trials in Advanced Prostate Cancer

A new investigational agent code‑named GLR2037 has entered early clinical development as a first‑in‑human phase 1 study in patients with advanced prostate cancer, representing a significant step in the evolution of androgen receptor–directed therapies. GLR2037 is an androgen receptor (AR)–targeting proteolysis‑targeting chimera (PROTAC), designed not merely to inhibit the AR but to promote its ubiquitin‑proteasome–mediated degradation, thereby aiming to bypass common resistance mechanisms such as AR mutations, amplifications, and splice‑variant‑driven signaling that limit the efficacy of current AR inhibitors.

The trial is an open‑label, dose‑escalation phase 1 study embedded within a broader program focused on targeted protein degradation. Its primary goals are to define the safety profile of GLR2037, identify dose‑limiting toxicities, and establish a recommended phase II dose for subsequent development. Secondary and exploratory endpoints include characterization of pharmacokinetic behavior, assessment of pharmacodynamic markers of AR degradation and downstream androgen signaling, and early evaluation of antitumor activity through measures such as prostate‑specific antigen (PSA) declines, radiographic responses, and progression‑free survival.
The study is expected to enroll men with advanced prostate cancer, including those with metastatic castration‑resistant (mCRPC) and potentially metastatic hormone‑sensitive (mHSPC) disease, with relatively broad eligibility regarding prior therapies but with strict exclusion criteria for major organ dysfunction or active uncontrolled comorbidities.

Clinical trial.