A Study of ABSK061 to Assess Safety, Tolerability, Pharmacokinetics, and Efficacy in Children With Achondroplasia

NCT07297875 | Not Yet Recruiting Phase 1

• 1 other identifier: ABSK061-202
• Study Type: interventional
• Target: 110
• Locations: 1 country
• Sites: 7

Brief Summary

This is a multicenter, non-randomized, open-label, phase I/II study in children with ACH. This study will start with a dose escalation of ABSK061 in children with ACH to evaluate the safety, tolerability, PK, and efficacy. The RDE confirmation part will evaluate the safety and efficacy of ABSK061 at the recommended doses for expansion (RDEs) in children with ACH. All patients enrolled in the dose escalation part and RDE confirmation part can enter the extended treatment period to further evaluate the long-term safety, tolerability, and long-term efficacy of ABSK061 in children with ACH.

Conditions

Achondroplasia

Outcome Measures

Primary Outcomes (3)

• Incidence of dose-limiting toxicities (DLTs)

  Incidence of dose-limiting toxicities (DLTs) in the DLT observation period, defined as Day 1 to Day 28 of dosing

  Day 1 to Day 28 of dosing

• Incidence and severity of adverse events (AEs)

  Incidence and severity of adverse events (AEs), adverse events of special interest (AESIs), and serious adverse events (SAEs) using Common Terminology Criteria for Adverse Events, version 5.0 (CTCAE v5.0), and relatedness, rate of dose modifications (including dose interruption and dose reduction) or discontinuation of study drug due to toxicity, and changes from baseline in safety assessments such as laboratory parameters, x-ray, electrocardiograms (ECGs), echocardiograms, vital signs, and physical examinations (including ophthalmic examinations)

  up to 87 weeks

• Changes from baseline in the Annualized Growth Velocity (AGV, cm/year)

  Changes from baseline in the Annualized Growth Velocity (AGV, cm/year) over 52 weeks \[baseline is defined as the AGV obtained through at least 6 months of observation in the observational study (ABSK061-001)\]

  Day 1 of dosing to 78-week End of Treatment

Secondary Outcomes (14)

• Cmax

  Day 1 of dosing to 78-week End of Treatment

• Tmax

  Day 1 of dosing to 78-week End of Treatment

• AUC

  Day 1 of dosing to 78-week End of Treatment

• t1/2

  Day 1 of dosing to 78-week End of Treatment

• Vz/F

  Day 1 of dosing to 78-week End of Treatment

Other Outcomes (1)

• Range of Motion (ROM)

  Day 1 of dosing to 78-week End of Treatment

Study Arms (1)

ABSK061

EXPERIMENTAL

Dose escalation part will be divided into Part A and Part B according to patient age, with Part A enrolling children with ACH aged 6 to \< 12 years (inclusive of 6 years) and Part B enrolling children with ACH aged 3 to \< 6 years (inclusive of 3 years). In this study, two sentinel patients will be set for both parts of each dose level, thereby the interval for the first dose between the first 2 patients and the third patient is not less than 28 days. This study will employ the Bayesian optimal interval (BOIN) design for dose escalation part to guide dose escalation. The target toxicity rate for the MTD is φ = 0.25 and the maximum sample size for the dose escalation part will be 80 (50 in Part A and 30 in Part B). The DLT observation period is defined as the first 28 days after administration of ABSK061. After the RDE is confirmed in the dose Escalation part, the dose Expansion phase will be conducted.

Drug: ABSK061

Interventions

ABSK061 DRUG

ABSK061 is supplied as minitablets filled in capsules. Four strengths of capsules will be provided: 0.2 mg, 2 mg, 3 mg, and 5 mg. Each patient can only be administered with a single strength. All patients will be administered orally once daily under the fasted state, i.e., fast from 2 hours before dosing to 1 hour after dosing. Dose will be calculated based on the patient's weight, and detailed rules for dose calculation are provided. Take out the ABSK061 capsule containing minitablets, take off the capsule cap and decant the content (minitablets), swallow the minitablets completely with water without chewing (the recommended water volume is 50-180 mL). If there is difficulty swallowing all the minitablets at once, they may be taken in several portions as needed, but the entire dose should be taken within 10 minutes. If needed, yogurt or apple sauce can be used as vehicles to facilitate swallowing of the minitablets.

ABSK061

Eligibility Criteria

• Age: 3 Years - 12 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• Prior to screening, the guardians and children with ACH (if applicable) must voluntarily provide signed informed consent.
• Patients with a clear clinical diagnosis of ACH confirmed by genetic testing for an FGFR3 mutation.
• Male or female, age at screening:
• Dose Escalation Part A: 6 to \< 12 years (inclusive 6 years) Dose Escalation Part B: 3 to \< 6 years (inclusive 3 years) RDE Confirmation Part: 3 to \< 12 years (inclusive 3 years).
• Have completed at least 6 months (i.e., the "Day 181" visit) of growth assessment and observation of natural history of ACH in the observational study (ABSK061-001) before study entry.
• Tanner Stage 1 breast development for females or Tanner Stage 1 external genitalia development for males at screening

You may not qualify if:

• Known allergy or hypersensitivity to any component of the study drug.
• Bone age ≥ 14 years as assessed by the investigator based on hand and wrist X-ray.
• Have a form of skeletal dysplasia other than ACH or known medical conditions that result in short stature or abnormal growth, including but not limited to severe achondroplasia with developmental delay and acanthosis nigricans (SADDAN), Turner syndrome, pseudoachondroplasia, inflammatory bowel disease, chronic renal insufficiency, active celiac disease a, Vitamin D deficiency b, untreated hypothyroidism c, poorly controlled diabetes (HbA1c ≥8.0%) or diabetic complications
• History or presence of injury or disease of the growth plate(s), other than ACH, that affects growth potential of long bones.
• AGV ≤ 1.5 cm/year over at least 6 months (i.e., must have completed the 'Day 181' visit) in the observational study (ABSK061-001), or current evidence of growth plate closure (proximal tibia, distal femur).
• Current epiphyseal injury (Salter-Harris fracture) or severe hip pain.
• For ACH-related complications: current severe sleep apnea, symptomatic and/or requiring intervention for hydrocephalus, or spinal cord compression at the cranio-cervical junction, or prior ventriculoperitoneal shunt surgery.
• Have received any dose of medications affecting stature or body proportionality, such as human growth hormone, insulin-like growth factor 1 (IGF-1), or anabolic steroids within 12 months prior to screening.
• Prior treatment with any CNP analogues or FGFR inhibitors. Prior use of any investigational drugs or investigational medical devices that affect height or body proportion.
• History of any prior bone-related surgery that affects long bone growth, such as orthopaedic reconstructive surgery, limb lengthening, or osteotomy (patients who have previously undergone foramen magnum decompression or intervertebral disc/laminectomy are allowed if they have fully recovered after surgery and bone healing has occurred for at least 6 months. Patients who have previously undergone eight-plate epiphysiodesis are allowed if the plate has been removed and healed for at least 4 weeks).

Sponsors & Collaborators

• Abbisko Therapeutics Co, Ltd: lead

Study Sites (7)

Beijing Children's Hospital, Capital Medical University

Beijing, Beijing Municipality, China

Location

Henan Children's Hospital, Zhengzhou Children's Hospital

Zhengzhou, Henan, China

Location

Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology

Wuhan, Hubei, China

Location

Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine

Shanghai, Shanghai Municipality, China

Location

Chengdu Women's and Children's Central Hospital

Chengde, Sichuan, China

Location

West China Second University Hospital, Sichuan University

Chengdu, Sichuan, China

Location

Children's Hospital Zhejiang University School of Medicine

Hangzhou, Zhejiang, China

Location

MeSH Terms

Conditions

Achondroplasia

Condition Hierarchy (Ancestors)

Dwarfism; Bone Diseases, Developmental; Bone Diseases; Musculoskeletal Diseases; Osteochondrodysplasias; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities

Study Officials

• Shuqi Zeng

  12B, Building 1, No 515, Huanke Road, Pudong New Area, Shanghai 201210, China

  STUDY DIRECTOR

Central Study Contacts

Jing Zhang

CONTACT

+86-15002126439; jing.zhang@abbisko.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: November 24, 2025
• First Posted: December 22, 2025
• Study Start: December 10, 2025
• Primary Completion (Estimated): December 15, 2028
• Study Completion (Estimated): March 15, 2031
• Last Updated: December 22, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share

Locations

CN (7)