NCT05431270

Dose Escalation/Expansion Study of Mavrostobart (PT199), an Anti-CD73 MAb, Administered Alone and in Combination with a PD-1 Inhibitor or Chemotherapy (the MORNINGSTAR Study)

A Phase 1, Open-Label, Dose Escalation and Expansion Study of Mavrostobart (PT199) Administered Alone in Adult Patients with Advanced Solid TuMORs, in CombiNation with a Checkpoint INhibitor TreatinG Wild-type Non-Small Cell Lung Cancer, or in Combination with ChemoTherapy for Metastatic or Advanced PAncreatic Ductal AdenocaRcinoma (MORNINGSTAR)

• Status: Recruiting
• Phase: Phase 1 / Phase 2
• Study type: Interventional
• Enrollment: 40 (estimated)
• Sponsor: Phanes Therapeutics · Industry
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

This is a first-in-human, Phase 1/2, open-label, study designed to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary efficacy of Mavrostobart (PT199) alone and in combination with a PD-1 inhibitor or chemotherapy.

Detailed description

Mavrostobart (PT199) is an anti-CD73 mAb with a differentiated mechanism of action and is expected to completely inhibit CD73 enzyme activity. Mavrostobart (PT199) is designed to counter the adenosine-mediated immunosuppressive tumor microenvironment, rendering anti-tumor immune cells to be more active and more responsive to checkpoint immunotherapies, such as PD-1/PD-L1 inhibitors. CD73 is widely overexpressed in a number of different cancers, including pancreatic ductal adenocarcinoma (PDAC), gastric carcinoma, colorectal carcinoma, non-small cell lung cancer (NSCLC), sarcomas and glioblastomas. Thus, targeting CD73 may provide benefit for patients with a high CD73 expression in their tumor. Mavrostobart (PT199) addresses the limitations of current CD73 inhibitors and is expected to increase antitumor immune activation, especially in combination with PD-1 pathway inhibition, and thus offer a new treatment option for cancer patients. NSCLC is known to have a high expression level of CD73, and emerging clinical data has shown that targeting CD73 may provide clinical benefit, when combined with an immune checkpoint inhibitor (ICI) and/or standard of care chemotherapies to overcome treatment resistance.

Conditions

• Non Small Cell Lung Cancer
• Pancreatic Ductal Adenocarcinoma

Interventions

Type	Name	Description
DRUG	Mavrostobart (PT199)	Mavrostobart (PT199) is an anti-CD73 mAb with a differentiated mechanism of action.
DRUG	Tislelizumab	Anti-PD-1 monoclonal antibody 200 mg Q3W, inhibits the lymphocytes PD-1 receptors, blocking the ligands that would deactivate it and prevent an immune response.
DRUG	Gemcitabine + nab-Paclitaxel	Dosing is per Standard of Care.
DRUG	Docetaxel	Dosing is per Standard of Care.
DRUG	Pemetrexed	Dosing is per Standard of Care.
DRUG	Gemcitabine	Dosing is per Standard of Care.
DRUG	Carboplatin + Pemetrexed	Dosing is per Standard of Care.
DRUG	Pembrolizumab + Carboplatin + Pemetrexed	Dosing is per Standard of Care.

Timeline

• Start date: 2022-08-11
• Primary completion: 2027-12-01
• Completion: 2028-08-01
• First posted: 2022-06-24
• Last updated: 2025-01-31

Locations

6 sites across 1 country: United States

Regulatory

• FDA-regulated drug study