Phase I Study of FXS887 in the Treatment of Solid Tumors

NCT07345637 | Not Yet Recruiting Phase 1

• 1 other identifier: FXS887-I101
• Study Type: interventional
• Target: 14
• Locations: 1 country
• Sites: 1

Brief Summary

This is a single-arm, open-label, dose-escalation and dose-expansion Phase I clinical trial evaluating the safety, tolerability, pharmacokinetics, and preliminary efficacy of FXS887 in patients with advanced solid tumors. FXS887 is a innovative ATR inhibitors of a class of small-molecule inhibitors targeting ATR kinase.

Conditions

Solid Tumor Refractory to Conventional Treatment

Outcome Measures

Primary Outcomes (4)

• Number of participants with DLTs

  DLTs will be assessed during the dose-escalation phase and are defined as toxicities that meet pre-defined DLT criteria and assessed as having a suspected relationship to study drug, and unrelated to disease, disease progression, intercurrent illness, or concomitant medications that occurs within the first cycle (28 days) of treatment.

  Up to Day 28

• Maximum tolerated dose (MTD) or Maximum administered dose(MAD)

  The MTD is defined as the highest dose level at which the proportion of subjects who experience Dose-Limiting Toxicity (DLT) is less than 1/3 during the DLT observation period. If the MTD is not established after the completion of the dose-escalation, the highest safe dose level will be defined as the MAD.

  Up to 12 Months

• Incidence of Treatment-Emergent Adverse Events (TEAEs)[Safety and Tolerability]

  Number and frequency of subjects with adverse events, including changes in vital signs, electrocardiograms (ECGs), physical examinations, and laboratory parameters, graded according to NCI CTCAE v5.0.

  From first dose of study drug until 30 days after the last dose.

• Phase 1a: recommended phase 2 dose (RP2D)

  The RP2D (Recommended Phase 2 Dose) determined based on comprehensive consideration of safety, tolerability, PK (pharmacokinetics), PD (pharmacodynamics), and efficacy data.

  Up to 12 Months

Secondary Outcomes (6)

• Peak Plasma Concentration (Cmax) of FXS887

  From the day of first dose to 30 days after last dose of FXS887

• Area under the plasma concentration-time curve (AUC)of FXS887

  From the day of first dose to 30 days after last dose of FXS887

• Time to reach maximum plasma concentration (Tmax) of FXS887

  From the day of first dose to 30 days after last dose of FXS887

• Elimination Half-Life (t1/2) of FXS887

  From the day of first dose to 30 days after last dose of FXS887

• Objective response rate, ORR

  From first dose of study drug until the date of first documented disease progression or death from any cause, whichever occurs first, assessed up to 24 months.

Study Arms (1)

FXS887

EXPERIMENTAL

This is a single-arm, open-label, dose-escalation and dose-expansion Phase I clinical trial evaluating the safety, tolerability, pharmacokinetics, and preliminary efficacy of FXS887 in patients with advanced solid tumors. It mainly consists of two parts: the Phase Ia dose-escalation study and the Phase Ib dose-expansion study. Participants will receive FXS887 orally once-daily at determined dose levels on a 28-day cycle.

Drug: FXS887

Interventions

FXS887 DRUG

FXS887 is an innovative ATR inhibitor targeting ATR kinase.

FXS887

Eligibility Criteria

• Age: 18 Years+
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Aged ≥ 18 years, male or female;
• Participants must fully understand the requirements of the study and voluntarily sign the written informed consent;
• Participants with histologically/cytologically confirmed advanced solid tumors who have received ≥ 1 line of systemic therapy prior to enrollment in the study and experienced failure of standard therapy (disease progression or intolerance);
• Per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1, participants must have at least one measurable target lesion;
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1;
• Estimated life expectancy of ≥ 12 weeks;
• Participants must have adequate organ and bone marrow function.
• For female participants of childbearing age, the serum pregnancy test within 7 days prior to the first dose of the study drug must be negative; eligible participants of reproductive potential (both males and females) must agree to use reliable contraceptive methods (hormonal, barrier, abstinence, etc.) with their partners during the study period and for at least 6 months after the last dose of the study drug.

You may not qualify if:

• Within the washout period of prior anti-tumor medication treatment (4 weeks or 5 half-lives after the last dose, whichever is longer) prior to the first dose of FXS887;
• Have participated in another clinical study within 4 weeks prior to the first dose of FXS887;
• Have a history of hypersensitivity to any known components of FXS887 or its analogues;
• Have intolerance to ATR inhibitors or have received ATR inhibitors within 4 weeks or 5 half-lives (whichever is longer) prior to the first dose of FXS887;
• Need to take strong CYP3A inhibitors and/or inducers, as well as P-gp (P-glycoprotein) inhibitors and/or inducers within 14 days (or 5 half-lives, whichever is longer) prior to the first dose of FXS887 and during the study period;
• Need to take drugs known to prolong the QTc interval during the study period;
• Have had other malignant tumors within 2 years prior to the first dose of FXS887, except for local tumors that have been cured and judged by the investigator to have a low risk of recurrence;
• Have received radiation therapy within 14 days prior to the first dose of FXS887;
• Have refractory nausea and vomiting, chronic gastrointestinal diseases including but not limited to active diverticulitis and symptomatic peptic ulcers, inability to swallow oral medications, or a history of extensive small bowel resection or other conditions that significantly impair gastrointestinal absorption as judged by the investigator;
• Have undergone major surgery within 2 weeks prior to the first dose or have not recovered from surgical complications;
• Have primary central nervous system (CNS) tumors, meningeal metastasis, spinal cord compression, or brainstem metastasis; participants with known untreated brain metastases or symptomatic or unstable disease are excluded; participants who have completed treatment for brain metastases (radiation therapy or surgery) with stable metastases and no relevant symptoms (without medication control) within 4 weeks prior to the first dose may be enrolled;
• Have severe cardiovascular diseases;
• Have uncontrolled pleural effusion, pericardial effusion, or ascites requiring repeated drainage and medical intervention;
• Have active infections requiring treatment (e.g., participants are receiving anti-infective treatment) within 14 days prior to the first dose of FXS887, including Hepatitis C virus (HCV), Human Immunodeficiency Virus (HIV), uncontrolled active Hepatitis B virus (HBV) infection, syphilis infection, known active tuberculosis, etc.
• Known infection with hepatitis B virus (HBV) or hepatitis C virus (HCV):

Sponsors & Collaborators

• Shanghai Fosun Pharmaceutical Industrial Development Co. Ltd.: lead

Study Sites (1)

Fudan University Shanghai Cancer Center

Shanghai, Shanghai Municipality, 200032, China

Location

Central Study Contacts

Xiaohua Wu

CONTACT

+86 21 6417 5590; wu.xh@fudan.edu.cn

Jian Zhang

CONTACT

86 21 6417 5590; syner2000@163.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: December 23, 2025
• First Posted: January 16, 2026
• Study Start: January 5, 2026
• Primary Completion (Estimated): April 28, 2027
• Study Completion (Estimated): December 31, 2027
• Last Updated: January 16, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)