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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)

Phase 1
Recruiting
Conditions
Non Small Cell Lung Cancer
Pancreatic Ductal Adenocarcinoma
Interventions
Drug: Mavrostobart (PT199)
Drug: Carboplatin + Pemetrexed
Drug: Pembrolizumab + Carboplatin + Pemetrexed
Registration Number
NCT05431270
Lead Sponsor
Phanes Therapeutics
Brief 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.

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
40
Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type
INTERVENTIONAL
Study Design
SEQUENTIAL
Arm && Interventions
GroupInterventionDescription
Part A: Monotherapy Dose EscalationMavrostobart (PT199)A standard 3+3 dose escalation design will be employed, and 3 patients will be enrolled initially at each dose level. Mavrostobart (PT199) will be administered as a monotherapy.
Part B: Combination Therapy Dose EscalationMavrostobart (PT199)A standard 3+3 dose escalation design will be employed, and 3 patients will be enrolled initially at each dose level. Patients will be treated with Mavrostobart (PT199) in combination with a PD-1 inhibitor, tislelizumab.
Part B: Combination Therapy Dose EscalationTislelizumabA standard 3+3 dose escalation design will be employed, and 3 patients will be enrolled initially at each dose level. Patients will be treated with Mavrostobart (PT199) in combination with a PD-1 inhibitor, tislelizumab.
Part C: Combination Therapy Dose ExpansionMavrostobart (PT199)Two RDEs for Part C will be determined in Part B and will be further evaluated in two dose expansion cohorts. Patients will be treated with Mavrostobart (PT199) in combination with a PD-1 inhibitor, tislelizumab.
Part C: Combination Therapy Dose ExpansionTislelizumabTwo RDEs for Part C will be determined in Part B and will be further evaluated in two dose expansion cohorts. Patients will be treated with Mavrostobart (PT199) in combination with a PD-1 inhibitor, tislelizumab.
Part D: Chemotherapy CombinationMavrostobart (PT199)The Chemotherapy Combination Therapy Dose Escalation and Expansion will investigate four cohorts, one in frontline PDAC, two in frontline NSCLC and one in second-line and later NSCLC patients. Patients will receive Mavrostobart (PT199) plus chemotherapy, with one cohort also receiving pembrolizumab.
Part D: Chemotherapy CombinationGemcitabine + nab-PaclitaxelThe Chemotherapy Combination Therapy Dose Escalation and Expansion will investigate four cohorts, one in frontline PDAC, two in frontline NSCLC and one in second-line and later NSCLC patients. Patients will receive Mavrostobart (PT199) plus chemotherapy, with one cohort also receiving pembrolizumab.
Part D: Chemotherapy CombinationDocetaxelThe Chemotherapy Combination Therapy Dose Escalation and Expansion will investigate four cohorts, one in frontline PDAC, two in frontline NSCLC and one in second-line and later NSCLC patients. Patients will receive Mavrostobart (PT199) plus chemotherapy, with one cohort also receiving pembrolizumab.
Part D: Chemotherapy CombinationPemetrexedThe Chemotherapy Combination Therapy Dose Escalation and Expansion will investigate four cohorts, one in frontline PDAC, two in frontline NSCLC and one in second-line and later NSCLC patients. Patients will receive Mavrostobart (PT199) plus chemotherapy, with one cohort also receiving pembrolizumab.
Part D: Chemotherapy CombinationGemcitabineThe Chemotherapy Combination Therapy Dose Escalation and Expansion will investigate four cohorts, one in frontline PDAC, two in frontline NSCLC and one in second-line and later NSCLC patients. Patients will receive Mavrostobart (PT199) plus chemotherapy, with one cohort also receiving pembrolizumab.
Part D: Chemotherapy CombinationCarboplatin + PemetrexedThe Chemotherapy Combination Therapy Dose Escalation and Expansion will investigate four cohorts, one in frontline PDAC, two in frontline NSCLC and one in second-line and later NSCLC patients. Patients will receive Mavrostobart (PT199) plus chemotherapy, with one cohort also receiving pembrolizumab.
Part D: Chemotherapy CombinationPembrolizumab + Carboplatin + PemetrexedThe Chemotherapy Combination Therapy Dose Escalation and Expansion will investigate four cohorts, one in frontline PDAC, two in frontline NSCLC and one in second-line and later NSCLC patients. Patients will receive Mavrostobart (PT199) plus chemotherapy, with one cohort also receiving pembrolizumab.
Primary Outcome Measures
NameTimeMethod
To determine the maximum tolerated dose (MTD), if reached.Start of the study drug till 90 days after last dose.
Recommended Phase 2 Dose of Mavrostobart (PT199) as a single agent and/or in combination with a PD-1 inhibitor.Start of the study drug till 90 days after last dose.
Dose Limiting Toxicity (DLT).Time Frame: Start of the study drug till 90 days after last dose.
Secondary Outcome Measures
NameTimeMethod
Preliminary efficacy assessed by the response rate by RECIST 1.1 for overall response rate.Start of the study drug till 90 days after last dose.
Area Under the Curve from time 0 to last (AUC0-last) of Mavrostobart (PT199)Time Frame: Start of the study drug till 90 days after last dose.
Maximum Concentration (Cmax) of Mavrostobart (PT199)Time Frame: Start of the study drug till 90 days after last dose.
Half Life (T1/2) of Mavrostobart (PT199)Time Frame: Start of the study drug till 90 days after last dose.
Preliminary efficacy assessed by the response rate by RECIST 1.1 for disease control rate.Time Frame: Start of the study drug till 90 days after last dose.
Progression free survival duration.Time Frame: Start of the study drug till 90 days after last dose.
6-month overall survival.Time Frame: Start of the study drug till 90 days after last dose.

Trial Locations

Locations (6)

Carolina BioOncology Institute

🇺🇸

Huntersville, North Carolina, United States

Sarah Cannon Research Institute University of Oklahoma

🇺🇸

Oklahoma City, Oklahoma, United States

SCRI Oncology Partners

🇺🇸

Nashville, Tennessee, United States

The University of Texas MD Anderson Cancer Center

🇺🇸

Houston, Texas, United States

Tranquility Research

🇺🇸

Webster, Texas, United States

NEXT Oncology

🇺🇸

Fairfax, Virginia, United States

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