A Study to Evaluate ATX-898 in Participants With Advanced Solid Tumors
- Summary
- Study ATX-898-101 is a phase 1/2 open-label study evaluating the safety, tolerability, pharmacokinetic, and preliminary efficacy of ATX-898 as monotherapy and in combination with anti-neoplastic agents in selected solid tumors. This study consists of 2 parts. Part 1 evaluates ATX-898 as monotherapy and Part 2 evaluates ATX-898 in combination with anti-neoplastic agents of interest. Both parts will consists of a dose escalation portion and a dose expansion portion.
- Short title
- A Study to Evaluate ATX-898 in Participants With Advanced Solid Tumors
- Official title
- First-in-human Study of ATX-898, as Monotherapy and in Combination With Other Anti-neoplastic Agents, in Participants With Advanced Solid Tumors
- Control arm
- Open label
- Registry reports results
- Listing at source
- Listed
- Recruitment status
- Not yet recruiting
- Phase
- Phase 1/Phase 2
- Study type
- Interventional
- Completion date
- 2030-01-31
- First posted
- 2026-08-17
- Registry last updated
- 2026-08-17
- Primary completion date
- 2028-10-28
- Start date
- 2026-08-01
- Participants
- Participant count basis
- Estimated
- Planned participants
- Protocol amendments
- Data monitoring committee
- Registry sponsor category
- Industry
- Lead sponsor
- Antares Therapeutics, Inc
- Source registry
- ClinicalTrials.gov
- Registry ID
- NCT07767474
- ClinicalTrials.gov ID
- NCT07767474
- Registry record
- Open registry record
- Allocation
- Not randomised
- Model
- Sequential
- Purpose
- Treatment
- Masking
- No masking
Part 1a monotherapy dose escalation - Occurrence of Dose limiting toxicities (DLTs)
Timeframe: 12 months
Toxicities occurring within the first treatment cycle (28 days). DLTs will be assessed in severity by the investigators per CTCAE v 6.0
Part 1a monotherapy dose escalation - Maximally tolerated/tested dose (MTD)
Timeframe: 12 months
Maximum dose deemed safe and well tolerated during dose escalation
Part 1a monotherapy dose escalation - Recommended dose for expansion (RDE)
Timeframe: 12 months
Monotherapy dose recommended to test during dose expansion
Part 1a monotherapy dose escalation - Treatment emergent adverse events (TEAEs)
Timeframe: 12 months
Any adverse event (AE) either reported for the first time or worsening of a pre-existing event after first dose of study drug.
Part 1b monotherapy dose expansion - Objective Response Rate (ORR)
Timeframe: 24 months
Percentage of participants with confirmed CR or PR per RECIST 1.1
Part 2a combination dose escalation - Occurrence of Dose limiting toxicities (DLTs)
Timeframe: 18 months
Toxicities occurring within the first treatment cycle of combination therapy (28 days). DLTs will be assessed in severity by the investigators per CTCAE v 6.0
Part 2a combination dose escalation - Maximally tolerated/tested dose (MTD)
Timeframe: 18 months
Maximum dose deemed safe and well tolerated during dose escalation of with combination treatment
Part 2a combination dose escalation - Recommended dose for expansion (RDE)
Timeframe: 18 months
Recommended dose for expansion (RDE) Monotherapy dose recommended to test during dose expansion of combination treatment 18 months
Part 2a combination dose escalation - Treatment emergent adverse events (TEAEs)
Timeframe: 18 months
Any adverse event (AE) either reported for the first time or worsening of a pre-existing event after first dose of study drug. 18 months
Part 2b combination dose expansion - Objective Response Rate (ORR)
Timeframe: 36 months
Percentage of participants with confirmed CR or PR per RECIST 1.1
Part 1a monotherapy dose escalation - Pharmacokinetic assessment Cmax
Timeframe: 12 months
Cmax of ATX-898 following treatment
Part 1a monotherapy dose escalation - Pharmacokinetic assessment Tmax
Timeframe: 12 Months
Time it takes for the study drug to reach peak concentration (Cmax) in the blood following treatment
Part 1a monotherapy dose escalation - Pharmacokinetic assessment AUC
Timeframe: 12 Months
Area under the conc-time curve exposure of the study drug following treatment
Part 1a monotherapy dose escalation - Pharmacokinetic assessment T 1/2
Timeframe: 12 Months
Time required for the concentration of study drug in the body to reduce by half following treatment
Part 1a monotherapy dose escalation - Pharmacokinetic assessment Ctrough
Timeframe: 12 Months
Lowest measured concentration of study drug in the blood right before the next scheduled dose
Part 1a monotherapy dose escalation - Objective Response Rate (ORR)
Timeframe: 12 months
Percentage of participants with confirmed CR or PR per RECIST 1.1
Part 1b monotherapy dose expansion - Treatment emergent adverse events (TEAEs)
Timeframe: 24 Months
Any adverse event (AE) either reported for the first time or worsening of a pre-existing event after first dose of study drug
Part 1b monotherapy dose expansion - Pharmacokinetic assessment Cmax
Timeframe: 12 months
Cmax of ATX-898 following treatment at RDE
Part 1b monotherapy dose escalation - Pharmacokinetic assessment Tmax
Timeframe: 12 Months
Time it takes for the study drug to reach peak concentration (Cmax) in the blood following treatment at RDE
Part 1b monotherapy dose escalation - Pharmacokinetic assessment AUC
Timeframe: 12 Months
Area under the conc-time curve exposure of the study drug following treatment at RDE
Part 1b monotherapy dose escalation - Pharmacokinetic assessment T 1/2
Timeframe: 12 Months
Time required for the concentration of study drug in the body to reduce by half following treatment at RDE
Part 1b monotherapy dose escalation - Pharmacokinetic assessment Ctrough
Timeframe: 12 Months
Lowest measured concentration of study drug in the blood right before the next scheduled dose at RDE
Part 2a combination dose escalation - Objective Response Rate (ORR)
Timeframe: 18 months
Percentage of participants with confirmed CR or PR per RECIST 1.1
Part 2a monotherapy dose expansion - Pharmacokinetic assessment Cmax
Timeframe: 12 months
Cmax of ATX-898 following treatment
Part 2a monotherapy dose escalation - Pharmacokinetic assessment Tmax
Timeframe: 12 Months
Time it takes for the study drug to reach peak concentration (Cmax) in the blood following treatment
Part 2a monotherapy dose escalation - Pharmacokinetic assessment AUC
Timeframe: 12 Months
Area under the conc-time curve exposure of the study drug following treatment
Part 2a monotherapy dose escalation - Pharmacokinetic assessment T 1/2
Timeframe: 12 Months
Time required for the concentration of study drug in the body to reduce by half following treatment
Part 2a monotherapy dose escalation - Pharmacokinetic assessment Ctrough
Timeframe: 12 Months
Lowest measured concentration of study drug in the blood right before the next scheduled dose
Part 2b combination dose expansion - Treatment emergent adverse events (TEAEs)
Timeframe: 36 months
Any adverse event (AE) either reported for the first time or worsening of a pre-existing event after first dose of study drug when given in combination
Part 2b monotherapy dose expansion - Pharmacokinetic assessment Cmax
Timeframe: 12 months
Cmax of ATX-898 following treatment at RDE when given in combination
Part 2b monotherapy dose escalation - Pharmacokinetic assessment Tmax
Timeframe: 12 Months
Time it takes for the study drug to reach peak concentration (Cmax) in the blood following treatment at RDE when given in combination
Part 2b monotherapy dose escalation - Pharmacokinetic assessment AUC
Timeframe: 12 Months
Area under the conc-time curve exposure of the study drug following treatment at RDE when given in combination
Part 2b monotherapy dose escalation - Pharmacokinetic assessment T 1/2
Timeframe: 12 Months
Time required for the concentration of study drug in the body to reduce by half following treatment at RDE when given in combination
Part 2b monotherapy dose escalation - Pharmacokinetic assessment Ctrough
Timeframe: 12 Months
Lowest measured concentration of study drug in the blood right before the next scheduled dose at RDE when given in combination
- Sex
- All
- Age groups
- Adults, Older adults
- Minimum age
- 18 Years
- Healthy volunteers
- No
- Has histologically or cytologically confirmed advanced solid tumor malignancy that is metastatic or locally advanced and unresectable
- Is ≥18 years of age at the time of signing the informed consent form
- ECOG performance status score of 0 or 1
- Adequate organ function
- Must consent to a pre-treatment tumor biopsy (collected during screening or have available archival tumor tissue in the past 5 years.
For Part 1a (monotherapy dose escalation)
- Has received one or more standard systemic therapies and additional standard therapies are either not available, or participant ineligible for available standard therapies For Part 1b (monotherapy dose expansion)
- b1: Has platinum-resistant or refractory metastatic ovarian cancer
- b2: Has recurrent or metastatic gynecologic cancer excluding the cancers eligible for b1
- b3: Has recurrent advanced or metastatic solid tumor excluding the cancers eligible for b1 or b2
- Has at least 1 measurable lesion per RECIST 1.1
For Part 2a (combination dose escalation)
- Has confirmed HR+ HER2 - (including HER2 low and ultra low) status
- Has received prior therapy in the metastatic For Part 2b (combination dose expansion)
- Has confirmed HR+ HER2 - (including HER2 low and ultra low) status
- Treatment-naïve or has received prior therapy in the metastatic setting
- Has history (within ≤2 years before screening) of a solid tumor or hematological malignancy that is histologically distinct from the cancer being studied
- Has symptomatic CNS metastases at screening or asymptomatic CNS metastases requiring corticosteroids to control symptoms within 28 days prior to the first dose of ATX-898.
- Has toxicities from previous anticancer therapies that have not resolved to baseline levels or to CTCAE Grade ≤1, with the exception of alopecia any grade and Grade ≤2 peripheral neuropathy
- Has any condition for which, in the opinion of the Investigator, participation would not be in the best interest of the participant or would prevent, limit, or confound the protocol-specified assessments
Cohort Specific:
- For abemaciclib cohorts only: has a history of any events of cardiac etiology that would contraindicate dosing with abemaciclib
- For ribocicilib only: has history of pneumonitis or interstitial lung disease