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CompletedNCT03389802Updated Aug 13, 2026Results posted

Phase I Study of APX005M in Pediatric Central Nervous System Tumors

A Phase 1 interventional study of APX005M treatment for recurrent or refractory primary malignant CNS tumor patients and APX005M treatment for newly diagnosed DIPG patients in Glioblastoma Multiforme, High-grade Astrocytoma Not Otherwise Specified (NOS) and CNS Primary Tumor, Not Otherwise Specified (NOS), sponsored by Pediatric Brain Tumor Consortium. Completed at 11 sites in United States. Open to participants aged 1 Year to 21 Years. Per ClinicalTrials.gov, last updated 2026-08-13.

Sponsored by Pediatric Brain Tumor Consortium · Phase 1, Interventional, and Treatment

Phase
Phase 1
Study type
Interventional
Enrollment
32
Allocation
Non-randomized
Ages
1 Year to 21 Years
Sex
All
01

Study summary

This phase I trial studies the side effects and best dose of APX005M in treating younger patients with primary malignant central nervous system tumor that is growing, spreading, or getting worse (progressive), or newly diagnosed diffuse intrinsic pontine glioma. APX005M can trigger activation of B cells, monocytes, and dendritic cells and stimulate cytokine release from lymphocytes and monocytes. APX005M can mediate a direct cytotoxic effect on CD40+ tumor cells.

Read the detailed description

This is a multicenter phase I trial of APX005M in patients with recurrent or refractory primary malignant central nervous system tumor, or newly diagnosed diffuse intrinsic pontine glioma.

APX005M is a humanized IgG1κ mAb that binds to CD40. APX005M binds to both human and cynomolgus monkey CD40 with high affinity, triggering activation of B cells, monocytes, and dendritic cells and stimulating cytokine release from both human and monkey lymphocytes and monocytes. APX005M does not bind to mouse or rat CD40. CD40 is also expressed on many human tumor cells, and APX005M can mediate a direct cytotoxic effect on CD40+ tumor cells.

Activation of CD40 on tumor cells results in tumor cell apoptosis and inhibition of tumor growth. CD40 agonistic antibodies have demonstrated potent antitumor immune response stimulation in both animal models and cancer patients. Due to its action on both immune and tumor cells, CD40 has been studied as a target for novel cancer immunotherapy.

Apexigen has declared the adult recommended phase 2 dose to be 0.3 mg/kg because no dose limiting toxicities were encountered at that dose and the pharmacodynamic profile was similar to the 1 mg/kg maximally tolerated dose. This phase 1 clinical trial is to study APX005M in children with central nervous system tumors.

02

Conditions studied

  • Glioblastoma Multiforme
  • High-grade Astrocytoma Not Otherwise Specified (NOS)
  • CNS Primary Tumor, Not Otherwise Specified (NOS)
  • Ependymoma, Not Otherwise Specified (NOS)
  • Diffuse Intrinsic Pontine Gliomas (DIPG)
  • Medulloblastoma
03

Who can participate

Ages eligible
1 Year to 21 Years
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • Diagnosis -- Stratum 1: Recurrent or refractory primary malignant CNS tumor patients Patients with a histologically confirmed diagnosis of a primary malignant non-brainstem CNS tumor (excluding DIPG patients) that is recurrent, progressive, or refractory. All tumors must have histologic verification at either the time of diagnosis or recurrence except patients with marker (+) CNS germ cell tumors.

Stratum 2: Newly diagnosed DIPG patients (on-hold until pediatric RP2D has been established in Stratum 1) Patients with diffuse intrinsic pontine gliomas (DIPGs) will be eligible 6 to 14 weeks post-completion of radiation therapy if they do not have any evidence of progression. Patients with newly diagnosed DIPGs, defined as tumors with a pontine epicenter and diffuse involvement of 2/3 or more of the pons, are eligible without histologic confirmation. Patients with pontine tumors that do not meet these criteria or not considered to be typical intrinsic pontine gliomas will only be eligible if the tumors have been biopsied and (1) are proven to be an anaplastic astrocytoma, glioblastoma multiforme, gliosarcoma, anaplastic mixed glioma or fibrillary astrocytoma or (2) have a histone mutation typically seen in DIPG. Patients with disseminated disease are not eligible, and MRI of spine must be performed if disseminated disease is suspected by the treating physician.

  • Available Pre-trial Tumor Tissue -- Stratum 1: Recurrent or refractory primary malignant CNS tumor patients must have adequate pre-trial frozen or FFPE tumor material (minimum of 10 unstained slides) available for use in the tumor mutation burden studies (section 9.1.5).

Stratum 2: Patients with DIPG who have pre-trial tumor tissue available are requested to submit tissue; however, this is not required for eligibility.

  • Age -- Patient must be ≥ 1 and ≤ 21 years of age at the time of enrollment.
  • Prior Therapy -- Newly Diagnosed DIPG patients Patients must have not received any prior therapy for treatment of their current CNS malignancy other than radiation therapy.

Refractory/Recurrent patients Patients must have recovered from the acute treatment related toxicities (defined as \< grade 1) of all prior chemotherapy, immunotherapy, radiotherapy or any other treatment modality prior to entering this study.

Myelosuppressive chemotherapy -- Patients must have received their last dose of known myelosuppressive anticancer therapy at least 21 days prior to enrollment or at least 42 days if nitrosourea.

Biological agent: Patient must have recovered from any acute toxicity potentially related to the agent and received their last dose of the biologic agent ≥ 7 days prior to study enrollment.

For agents that have known adverse events occurring beyond 7 days after administration, this period must be extended beyond the time during which adverse events are known to occur.

Monoclonal antibody treatment and agents with known prolonged half-lives: At least three half-lives must have elapsed prior to enrollment.

Radiation --

Patients must have had their last fraction of:

Craniospinal irradiation (>24Gy) or total body irradiation or radiation to greater than 50% of pelvis > 3 months prior to enrollment.

Focal irradiation >6 weeks prior to enrollment Local palliative irradiation (small port) ≥4 weeks

Autologous Stem Cell Transplant -- Patient must be ≥ 6 months since autologous bone marrow/stem cell transplant prior to enrollment and have CD4 counts above 200/mm3.

Surgery -- Patients must be at least 4 weeks (28 days) from major surgery and fully recovered from all acute effects of prior surgical intervention.

  • Inclusion of Women and Minorities -- Both males and females of all races and ethnic groups are eligible for this study
  • Neurologic Status -- Patients with neurological deficits should have deficits that are stable for a minimum of 1 week prior to enrollment.

Patients with seizure disorders may be enrolled if seizures are well controlled.

  • Performance Status -- Karnofsky Performance Scale (KPS for > 16 years of age) or Lansky Performance Score (LPS for ≤ 16 years of age) assessed within two weeks of enrollment must be ≥ 60. Patients who are unable to walk because of neurologic deficits, but who are up in a wheelchair, will be considered ambulatory for the purpose of assessing the performance score.
  • Organ Function --

Patients must have adequate organ and bone marrow function as defined below:

Absolute Neutrophil Count (ANC) ≥ 1.0 x 109 cells/ L Platelets ≥ 100 x 109 cells/L (unsupported, defined as no platelet transfusion within 7 days) Hemoglobin ≥ 8 g/dL (may receive transfusions) Total bilirubin ≤1.5 times institutional upper limit of normal (ULN) AST(SGOT)/ALT(SGPT) ≤ 3 x institutional upper limit of normal (ULN) Albumin ≥ 3 g/dl Serum creatinine based on age/gender as noted below. Patients that do not meet the criteria below but have a 24 hour Creatinine Clearance or GFR (radioisotope or iothalamate) ≥ 70 mL/min/1.73 m2 are eligible.

Age Maximum Serum Creatinine (mg/dL) 1 to \< 2 years 0.6, 0.6 (M, F); 2 to \< 6 years 0.8, 0.8 (M, F); 6 to \< 10 years 1, 1 (M, F); 10 to \< 13 years 1.2, 1.2 (M, F); 13 to \< 16 years 1.5, 1.4 (M, F); ≥ 16 years 1.7, 1.4 (M, F).

  • Cardiac Function: Left Ventricular Ejection Fraction (LVEF) > 50% ECG QTc ≤ 450 msec
  • Pulmonary Function: Oxygen saturation as measured by pulse oximetry is > 93% on room air and no evidence of dyspnea at rest
  • Growth Factors -- Patients must be off all colony- forming growth factor(s) for at least 1 week prior to enrollment (i.e., filgrastim, sargramostim or erythropoietin). 2 weeks must have elapsed if patients received PEG formulations.
  • Pregnancy Status -- Female patients of childbearing potential must have a negative serum or urine pregnancy test.
  • Pregnancy Prevention -- Female subjects with childbearing potential and male subjects should use effective contraception methods (or abstain from sexual activity) while being treated with APX005M and for 30 days following treatment.
  • Informed Consent -- The patient or parent/guardian is able to understand the consent and is willing to sign a written informed consent document according to institutional guidelines.

Exclusion criteria

Exclusion Criteria:

  • Concurrent Illness -- Patients with any clinically significant unrelated systemic illness (serious infections Grade ≥ 2 or significant cardiac, pulmonary, hepatic or other organ dysfunction), that in the opinion of the investigator would compromise the patient's ability to tolerate protocol therapy, put them at additional risk for toxicity or would interfere with the study procedures or results.

Patients with a history of any other malignancy, except patients with a secondary brain tumor if the patient's first malignancy has been in remission for at least 5 years from the end of treatment.

  • Concurrent Therapy -- Patients who are receiving any other anticancer or investigational drug therapy.

Patients requiring systemic treatment with either corticosteroids (greater than physiologic replacement, defined as dexamethasone 0.75 mg/m2/day) or other immunosuppressive medications within 14 days of study drug administration will be excluded. However, patients who require intermittent use of bronchodilators or local steroid injections will not be excluded from the study. Please see section 5.3 for a list of acceptable and unacceptable concomitant medications as well as reporting requirements.

  • Presence of Bulky Tumor --

Patients with bulky tumor on imaging are ineligible. Bulky tumor is defined as:

Tumor with any evidence of uncal herniation or midline shift Tumor that in the opinion of the site investigator, shows significant mass effect

  • Allergy -- Patients with a history of severe (Grade ≥ 3) hypersensitivity reaction to a monoclonal antibody are ineligible.
  • Allogeneic Hematopoietic Stem Cell Transplantation -- Patients who have received allogeneic hematopoietic stem cell transplantation are ineligible.
  • Autoimmune Diseases -- Patients with active autoimmune disease or documented history of autoimmune disease/syndrome that requires ongoing systemic steroids or systemic immunosuppressive agents, except Patients with vitiligo or well controlled asthma/atopy Patients with hypothyroidism stable on hormone replacement or Sjogren's syndrome
  • Inability to Participate -- Patients who in the opinion of the investigator are unwilling or unable to return for required follow-up visits or obtain follow-up studies required to assess toxicity to therapy or to adhere to drug administration plan, other study procedures, and study restrictions.
  • Bleeding Disorder -- Patients with a known coagulopathy or bleeding diathesis or require the use of systemic anticoagulant medication are not eligible.
  • Pregnancy Status -- Female patients must not be pregnant or breast-feeding.
04

Study design

Phase
Phase 1
Primary purpose
Treatment
Allocation
Non-randomized
Intervention model
Sequential assignment
Masking
None (open label)
Enrollment
32 participants (actual)

Study arms

  • Experimental
    Stratum 1

    The recurrent, progressive, or refractory primary malignant non-brainstem CNS tumor patients will be treated with APX005M.

    Biological: APX005M treatment for recurrent or refractory primary malignant CNS tumor patients

  • Experimental
    Stratum 2

    The newly diagnosed diffuse intrinsic pontine gliomas (DIPGs) patients will be treated with APX005M.

    Biological: APX005M treatment for newly diagnosed DIPG patients

Interventions

  • BiologicalAPX005M treatment for recurrent or refractory primary malignant CNS tumor patients

    APX005M dosing will begin at 0.1 mg/kg, the APX005M dose may be increased (0.3, 0.45, 0.6 mg/kg) or decreased (0.03 mg/kg) in subsequent cohorts until the maximum tolerated dose (MTD) is reached or until dose level 3 (0.6 mg/kg) is complete without the MTD being defined. APX005M will be administered at the assigned dose level every 21 days (3 weeks). Patients may continue to receive APX005M for 36 courses (approximately 2 years) or until disease progression, unacceptable toxicity or death, whichever occurs first.

  • BiologicalAPX005M treatment for newly diagnosed DIPG patients

    The starting dose of APX005M for the DIPG patients will be one dose level below the recommended phase II dose (RP2D) determined in Stratum 1 patients. The dose may be decreased or increased to the RP2D established in Stratum 1. APX005M will be administered at the assigned dose level every 21 days (3 weeks). Patients may continue to receive APX005M for 36 courses (approximately 2 years) or until disease progression, unacceptable toxicity or death, whichever occurs first.

05

What researchers measure

Primary outcomes

  1. Number of Patients Who Experienced Dose-limiting Toxicities (DLTs)

    DLTs were defined as adverse events (AE) at least possibly attributed to APX005M that occurred during the first 2 courses (6 weeks) following APX005M administration. DLTs included any APX005M-related AE that led to dose reduction or permanent cessation of therapy or resulted in a treatment delay \>2 weeks. Hematologic DLTs included grade 3 neutropenia with fever, any grade 4 hematologic toxicity except lymphopenia, and grade 3 thrombocytopenia on 2 separate days or requiring platelet transfusion on 2 days within a 7-day period. Non-hematologic DLTs included any grade 4 non-hematologic toxicity, grade 3 or higher cytokine release syndrome, or any grade 3 non-hematologic toxicity with some exceptions such as grade 3 nausea/vomiting \<5 days or grade 3 diarrhea that responded to treatment within 5 days.

    Time frame: 6 weeks

  2. Maximum Tolerated Dose (MTD) and/or Recommended Phase II Dose (RP2D) of APX005M in Stratum 1

    Based on the 3+3 design, the MTD of APX005M was empirically defined as the highest dose level at which six patients were treated with at most one patient experiencing a DLT, and the next higher dose level was determined to be too toxic. A total of 12 subjects were to be treated at the MTD/RP2D to further define the toxicity profile. Stratum 1 consisted of patients with recurrent or refractory primary malignant central nervous system tumors.

    Time frame: 6 weeks (first 2 courses of treatment)

  3. Maximum Tolerated Dose (MTD) and/or Recommended Phase II Dose (RP2D) of APX005M in Stratum 2

    The starting dose level for Stratum 2 was one dose level below the RP2D determined in Stratum 1. If there were no dose-limiting toxicities in the first 3 patients enrolled on Stratum 2, then we escalated to the Stratum 1 RP2D and could treat 6 diffuse intrinsic pontine glioma (DIPG) patients simultaneously. The RP2D was defined as the dose level at which 6 patients were treated with no more than one dose-limiting toxicity. Stratum 2 patients were those with newly diagnosed diffuse intrinsic pontine glioma (DIPG).

    Time frame: 6 weeks (first 2 courses of treatment)

  4. Serum Concentration of APX005M

    Serial blood samples for APX005M pharmacokinetic studies were collected during courses 1 and 2 at pre-dose, at the end of infusion, and at 4, 24 ± 1 (day 2), and 168 ± 4 hours (day 8) from the start of infusion in that course. During courses 3 and 4, samples were obtained pre-dose and end of induction. Serum concentrations of sotigalimab were measured using a validated electrochemiluminescent (ECL) immunoassay (Method ICD 853 v1.00). Mean serum concentrations with standard deviations were calculated using Phoenix® WinNonlin® v.8.4. Concentrations below the limit of quantitation (0.010 μg/mL) were replaced with 0 to calculate means and SDs.

    Time frame: Up to 12 weeks from start of study drug

Secondary outcomes

  1. Overall Survival for Stratum 2 (DIPG) Patients

    Overall survival was defined as the time interval from treatment initiation to death from any cause or to date of last follow-up for survivors. Survival was estimated using the method of Kaplan and Meier. The 1-year estimate of survival is reported with a 95% confidence interval; estimates are reported by dose level. Stratum 2 patients were those with newly diagnosed diffuse intrinsic pontine glioma (DIPG).

    Time frame: 1 year

  2. Progression-free Survival for Stratum 2 (DIPG) Patients

    Progression-free survival (PFS) was defined as the time interval from treatment initiation to date of first event (relapsed or progressive disease based on imaging or clinical progression or death from any cause) or to the date of last follow-up for patients without events. PFS was estimated using the method of Kaplan and Meier. The 1-year estimate of PFS is reported with a 95% confidence interval. PFS estimates were reported separately by dose level. Stratum 2 patients were those with newly diagnosed diffuse intrinsic pontine glioma (DIPG).

    Time frame: 1 year

  3. Overall Response Rate for Stratum 2 (DIPG) Patients

    Complete or partial responses were considered responses. Response was evaluated by imaging or clinical progression. The response rate (percentage of participants with responses) is reported with a 95% Blyth-Still-Casella confidence interval. Response rates are reported separately by dose level.

    Time frame: Up to 2 years

  4. Duration of Response for Stratum 2 (DIPG) Patients

    Complete or partial responses were considered responses. Response was evaluated by imaging or clinical progression. Duration of response was measured from the time measurement criteria are met for complete or partial response until the first date that recurrent or progressive disease was objectively documented.

    Time frame: Up to 2 years

  5. Progression-free Survival for Stratum 1 (Recurrent/Refractory) Patients

    Progression-free survival (PFS) was defined as the time interval from treatment initiation to date of first event (relapsed or progressive disease based on imaging or clinical progression or death from any cause) or to the date of last follow-up for patients without events. PFS was estimated using the method of Kaplan and Meier. The 1-year estimate of PFS is reported with a 95% confidence interval. PFS estimates were reported separately by dose level. Stratum 1 patients were those with recurrent or refractory primary malignant CNS tumors.

    Time frame: 1 year

Other outcomes

  1. Incidence of Anti-APX005M Antibodies

    Serial blood samples for anti-drug-antibodies (ADA) were to be collected prior to dosing on courses 1, 2, 3, and 4, then every third course (courses 7 and 10), and then every 4 courses (courses 14, 18, 22, 26, 30, 34) until the end of therapy visit and collected into serum tubes. Percentages of patients with positive anti-drug antibodies with a 95% Blyth-Still-Casella confidence interval are reported by time point.

    Time frame: Prior to dosing on courses 1, 2, 3, 4, 7, 10, 14, 18, 22, 26, 30, and 34 and at the end of therapy (up to end of course 36)

  2. Concentration of the Cytokine Tumor Necrosis Factor-alpha (TNF-alpha)

    The cytokine was quantitated using V-PLEX Human Proinflammatory Panel, a multiplex immunoassay kit developed by Meso Scale Diagnostics (MSD). A four-parameter logistic fit calibration curve was generated and used to calculate concentrations in tested samples. Analyses were performed at pre-treatment and 1 week following the first dose of drug and additionally at 2, 3, 6, and 9 weeks following the course 1 drug dose if feasible. The mean concentration of TNF-alpha in pg/ml was reported with a standard deviation. When only one patient was analyzed, the standard deviation was reported as 0 (rather than undefined).

    Time frame: Pre-treatment (week 0), 1 week, 2 week, 3 weeks, 6 weeks and 9 weeks post-treatment

  3. Concentration of the Cytokine Interleukin-8 (IL-8)

    The cytokine was quantitated using V-PLEX Human Proinflammatory Panel, a multiplex immunoassay kit developed by Meso Scale Diagnostics (MSD). A four-parameter logistic fit calibration curve was generated and used to calculate concentrations in tested samples. Analyses were performed at pre-treatment and 1 week following the first dose of drug and additionally at 2, 3, 6, and 9 weeks following the course 1 drug dose if feasible. The mean concentration of IL-8 in pg/ml was reported with a standard deviation. When only 1 participant analyzed, the standard deviation was reported as 0 (rather than undefined).

    Time frame: Pre-treatment (week 0), 1 week, 2 week, 3 weeks, 6 weeks and 9 weeks post-treatment

  4. Tumor Mutation Burden Based on Whole Exome Sequencing of Tumor Tissue

    Tumor mutation burden was defined as the number of somatic mutations per megabase. Average tumor mutation burden was reported with a standard deviation. When only one patient was analyzed, the standard deviation was reported as 0 rather than undefined.

    Time frame: Day 0 of treatment

  5. Tumor Mutation Burden Based on RNA Sequencing of Tumor Tissue

    Tumor mutation burden was defined as the number of somatic mutations per megabase. Average tumor mutation burden was reported with a standard deviation. When only one patient was analyzed, the standard deviation was reported as 0 rather than undefined.

    Time frame: Day 0 of treatment

  6. Mutation Burden Based on TCR Sequencing

    Mutation burden as detected by comparing the TCR sequencing of tumor tissue and/or PBMC. Mean numbers of clonotypes were reported by time point with standard deviations.

    Time frame: Day 0 and Days 7, 14, and 21 after the start of treatment

06

Results

Posted Oct 10, 2024

Participant flow

Patients ≥1 and ≤21 years of age with recurrent or refractory primary malignant central nervous system (CNS) tumors (Stratum 1) or newly diagnosed diffuse intrinsic pontine glioma (DIPG) (Stratum 2) were enrolled at Pediatric Brain Tumor Consortium (PBTC) member institutions. The first patient was enrolled on 3/1/2018 and the last patient was enrolled on 1/20/2023. Accrual was closed after the maximum tolerated dose/recommended phase II dose was determined for both strata.

Participant flow — Overall Study
MilestoneStratum 1, Dose Level 1Stratum 1, Dose Level 2Stratum 1, Dose Level 3Stratum 2, Dose Level 2Stratum 2, Dose Level 3
Started331565
Completed00000
Not completed331565
Withdrew: Lack of efficacy331361
Withdrew: Adverse event00104
Withdrew: Subject deemed ineligible after enrollment00100

Outcome measures

PrimaryNumber of Patients Who Experienced Dose-limiting Toxicities (DLTs)

DLTs were defined as adverse events (AE) at least possibly attributed to APX005M that occurred during the first 2 courses (6 weeks) following APX005M administration. DLTs included any APX005M-related AE that led to dose reduction or permanent cessation of therapy or resulted in a treatment delay \>2 weeks. Hematologic DLTs included grade 3 neutropenia with fever, any grade 4 hematologic toxicity except lymphopenia, and grade 3 thrombocytopenia on 2 separate days or requiring platelet transfusion on 2 days within a 7-day period. Non-hematologic DLTs included any grade 4 non-hematologic toxicity, grade 3 or higher cytokine release syndrome, or any grade 3 non-hematologic toxicity with some exceptions such as grade 3 nausea/vomiting \<5 days or grade 3 diarrhea that responded to treatment within 5 days.

Time frame:
6 weeks
Reported as:
Count of participants · Participants
Number of Patients Who Experienced Dose-limiting Toxicities (DLTs)
ParticipantsStratum 1, Dose Level 1Stratum 1, Dose Level 2Stratum 1, Dose Level 3Stratum 2, Dose Level 2Stratum 2, Dose Level 3
Number of Patients Who Experienced Dose-limiting Toxicities (DLTs)00203
PrimaryMaximum Tolerated Dose (MTD) and/or Recommended Phase II Dose (RP2D) of APX005M in Stratum 1

Based on the 3+3 design, the MTD of APX005M was empirically defined as the highest dose level at which six patients were treated with at most one patient experiencing a DLT, and the next higher dose level was determined to be too toxic. A total of 12 subjects were to be treated at the MTD/RP2D to further define the toxicity profile. Stratum 1 consisted of patients with recurrent or refractory primary malignant central nervous system tumors.

Time frame:
6 weeks (first 2 courses of treatment)
Reported as:
Number · mg/kg
Maximum Tolerated Dose (MTD) and/or Recommended Phase II Dose (RP2D) of APX005M in Stratum 1
mg/kgStratum 1
Maximum Tolerated Dose (MTD) and/or Recommended Phase II Dose (RP2D) of APX005M in Stratum 10.6
PrimaryMaximum Tolerated Dose (MTD) and/or Recommended Phase II Dose (RP2D) of APX005M in Stratum 2

The starting dose level for Stratum 2 was one dose level below the RP2D determined in Stratum 1. If there were no dose-limiting toxicities in the first 3 patients enrolled on Stratum 2, then we escalated to the Stratum 1 RP2D and could treat 6 diffuse intrinsic pontine glioma (DIPG) patients simultaneously. The RP2D was defined as the dose level at which 6 patients were treated with no more than one dose-limiting toxicity. Stratum 2 patients were those with newly diagnosed diffuse intrinsic pontine glioma (DIPG).

Time frame:
6 weeks (first 2 courses of treatment)
Reported as:
Number · mg/kg
Maximum Tolerated Dose (MTD) and/or Recommended Phase II Dose (RP2D) of APX005M in Stratum 2
mg/kgStratum 2
Maximum Tolerated Dose (MTD) and/or Recommended Phase II Dose (RP2D) of APX005M in Stratum 20.3
PrimarySerum Concentration of APX005M

Serial blood samples for APX005M pharmacokinetic studies were collected during courses 1 and 2 at pre-dose, at the end of infusion, and at 4, 24 ± 1 (day 2), and 168 ± 4 hours (day 8) from the start of infusion in that course. During courses 3 and 4, samples were obtained pre-dose and end of induction. Serum concentrations of sotigalimab were measured using a validated electrochemiluminescent (ECL) immunoassay (Method ICD 853 v1.00). Mean serum concentrations with standard deviations were calculated using Phoenix® WinNonlin® v.8.4. Concentrations below the limit of quantitation (0.010 μg/mL) were replaced with 0 to calculate means and SDs.

Time frame:
Up to 12 weeks from start of study drug
Reported as:
Mean · μg/mL
Serum Concentration of APX005M
μg/mLStratum 1, Dose Level 1Stratum 1, Dose Level 2Stratum 1, Dose Level 3Stratum 2, Dose Level 2Stratum 2, Dose Level 3
Course 1, pre-dose0 ± 00 ± 00 ± 00 ± 00 ± 0
Course 1, 1 hour0.120 ± 0.1153.95 ± 0.5269.15 ± 2.983.49 ± 0.9849.87 ± 1.95
Course 1, 4 hours0.0357 ± 02.29 ± 0.3496.64 ± 1.932.12 ± 1.067.88 ± 0.280
Course 1, 24 hours0 ± 00 ± 00.851 ± 1.440 ± 00.0136 ± 0.0137
Course 1, 168 hours0 ± 00 ± 00 ± 00 ± 00 ± 0
Course 2, pre-dose0 ± 01.26 ± 2.190 ± 00 ± 00 ± 0
Course 2, 1 hour0.148 ± 0.1354.10 ± 0.2478.47 ± 2.273.23 ± 1.489.63 ± 2.22
Course 2, 4 hours0.032 ± 0.02532.66 ± 0.1406.13 ± 1.871.55 ± 0.9597.41 ± 3.15
Course 2, 24 hours0 ± 00 ± 00.593 ± 0.8720 ± 00.0317 ± 0.0448
Course 2, 168 hours0 ± 00 ± 00 ± 00 ± 00 ± 0
Course 3, pre-dose0 ± 00 ± 00 ± 00 ± 00 ± 0
Course 3, 1 hour0.198 ± 03.54 ± 0.7217.33 ± 1.981.89 ± 19.53 ± 1.80
Course 4, pre-dose0 ± 00 ± 00 ± 00 ± 00 ± 0
Course 4, 1 hour0.0114 ± 03.98 ± 08.82 ± 3.111.26 ± 1.171.84 ± 0
SecondaryOverall Survival for Stratum 2 (DIPG) Patients

Overall survival was defined as the time interval from treatment initiation to death from any cause or to date of last follow-up for survivors. Survival was estimated using the method of Kaplan and Meier. The 1-year estimate of survival is reported with a 95% confidence interval; estimates are reported by dose level. Stratum 2 patients were those with newly diagnosed diffuse intrinsic pontine glioma (DIPG).

Time frame:
1 year
Reported as:
Number · Percent probability
Overall Survival for Stratum 2 (DIPG) Patients
Percent probabilityStratum 2, Dose Level 2Stratum 2, Dose Level 3
Overall Survival for Stratum 2 (DIPG) Patients40.0 (4.9 to 75.1)25.0 (0.0 to 55.0)
SecondaryProgression-free Survival for Stratum 2 (DIPG) Patients

Progression-free survival (PFS) was defined as the time interval from treatment initiation to date of first event (relapsed or progressive disease based on imaging or clinical progression or death from any cause) or to the date of last follow-up for patients without events. PFS was estimated using the method of Kaplan and Meier. The 1-year estimate of PFS is reported with a 95% confidence interval. PFS estimates were reported separately by dose level. Stratum 2 patients were those with newly diagnosed diffuse intrinsic pontine glioma (DIPG).

Time frame:
1 year
Reported as:
Number · Percent probability
Progression-free Survival for Stratum 2 (DIPG) Patients
Percent probabilityStratum 2, Dose Level 2Stratum 2, Dose Level 3
Progression-free Survival for Stratum 2 (DIPG) Patients16.7 (0.0 to 37.9)26.7 (0.0 to 58.3)
SecondaryOverall Response Rate for Stratum 2 (DIPG) Patients

Complete or partial responses were considered responses. Response was evaluated by imaging or clinical progression. The response rate (percentage of participants with responses) is reported with a 95% Blyth-Still-Casella confidence interval. Response rates are reported separately by dose level.

Time frame:
Up to 2 years
Reported as:
Number · percentage
Overall Response Rate for Stratum 2 (DIPG) Patients
percentageStratum 2, Dose Level 2Stratum 2, Dose Level 3
Overall Response Rate for Stratum 2 (DIPG) Patients0 (0.0 to 40.2)0 (0.0 to 63.2)
SecondaryDuration of Response for Stratum 2 (DIPG) Patients

Complete or partial responses were considered responses. Response was evaluated by imaging or clinical progression. Duration of response was measured from the time measurement criteria are met for complete or partial response until the first date that recurrent or progressive disease was objectively documented.

Time frame:
Up to 2 years

No measurements were reported for this outcome.

SecondaryProgression-free Survival for Stratum 1 (Recurrent/Refractory) Patients

Progression-free survival (PFS) was defined as the time interval from treatment initiation to date of first event (relapsed or progressive disease based on imaging or clinical progression or death from any cause) or to the date of last follow-up for patients without events. PFS was estimated using the method of Kaplan and Meier. The 1-year estimate of PFS is reported with a 95% confidence interval. PFS estimates were reported separately by dose level. Stratum 1 patients were those with recurrent or refractory primary malignant CNS tumors.

Time frame:
1 year
Reported as:
Number · Percent probability
Progression-free Survival for Stratum 1 (Recurrent/Refractory) Patients
Percent probabilityStratum 1, Dose Level 1Stratum 1, Dose Level 2Stratum 1, Dose Level 3
Progression-free Survival for Stratum 1 (Recurrent/Refractory) Patients0.00 (0 to 0)0 (0 to 0)10.7 (0.0 to 59.9)
Other pre-specifiedIncidence of Anti-APX005M Antibodies

Serial blood samples for anti-drug-antibodies (ADA) were to be collected prior to dosing on courses 1, 2, 3, and 4, then every third course (courses 7 and 10), and then every 4 courses (courses 14, 18, 22, 26, 30, 34) until the end of therapy visit and collected into serum tubes. Percentages of patients with positive anti-drug antibodies with a 95% Blyth-Still-Casella confidence interval are reported by time point.

Time frame:
Prior to dosing on courses 1, 2, 3, 4, 7, 10, 14, 18, 22, 26, 30, and 34 and at the end of therapy (up to end of course 36)
Reported as:
Number · percentage of patients with positive ADA
Incidence of Anti-APX005M Antibodies
percentage of patients with positive ADAStratum 1, Dose Level 1Stratum 1, Dose Level 2Stratum 1, Dose Level 3Stratum 2, Dose Level 2Stratum 2, Dose Level 3
Prior to Course 10 (0 to 77.64)0 (0 to 63.16)8.33 (0.43 to 34.89)0 (0 to 40.19)0 (0 to 52.71)
Prior to Course 233.33 (1.70 to 86.46)0 (0 to 63.16)0 (0 to 24.95)16.67 (0.85 to 59.81)0 (0 to 77.64)
Prior to Course 3100 (50.0 to 100.0)0 (0 to 63.16)50.0 (9.76 to 90.24)50.0 (9.76 to 90.24)0 (0 to 77.64)
Prior to Course 4100 (50.0 to 100.0)100 (50.0 to 100.0)50.0 (9.76 to 90.24)75 (24.86 to 98.73)0 (0 to 95.0)
Prior to Course 7—100 (50.0 to 100.0)50 (2.52 to 97.47)100 (50.0 to 100.0)0 (0 to 95.0)
Prior to Course 10——50 (2.52 to 97.47)100 (50.0 to 100.0)—
Prior to Course 14——100 (50.0 to 100.0)100 (50.0 to 100.0)—
Prior to Course 18——100 (50.0 to 100.0)——
Prior to Course 22——0 (0 to 95.0)——
Prior to Course 26——0 (0 to 95.0)——
End of Treatment100 (22.36 to 100)—33.33 (6.29 to 72.87)66.67 (13.54 to 98.30)0 (0 to 52.71)
Other pre-specifiedConcentration of the Cytokine Tumor Necrosis Factor-alpha (TNF-alpha)

The cytokine was quantitated using V-PLEX Human Proinflammatory Panel, a multiplex immunoassay kit developed by Meso Scale Diagnostics (MSD). A four-parameter logistic fit calibration curve was generated and used to calculate concentrations in tested samples. Analyses were performed at pre-treatment and 1 week following the first dose of drug and additionally at 2, 3, 6, and 9 weeks following the course 1 drug dose if feasible. The mean concentration of TNF-alpha in pg/ml was reported with a standard deviation. When only one patient was analyzed, the standard deviation was reported as 0 (rather than undefined).

Time frame:
Pre-treatment (week 0), 1 week, 2 week, 3 weeks, 6 weeks and 9 weeks post-treatment
Reported as:
Mean · pg/ml
Concentration of the Cytokine Tumor Necrosis Factor-alpha (TNF-alpha)
pg/mlStratum 1, Dose Level 1Stratum 1, Dose Level 2Stratum 1, Dose Level 3Stratum 2, Dose Level 2Stratum 2, Dose Level 3
Week 00.95 ± 01.24 ± 00.71 ± 0.280.87 ± 0.480.41 ± 0.18
Week 11.02 ± 0.221.31 ± 0.490.75 ± 0.190.92 ± 0.650.44 ± 0.10
Week 20.92 ± 0.351.43 ± 0.010.97 ± 0.380.79 ± 0.331.03 ± 0
Week 31.15 ± 01.42 ± 0.340.83 ± 0.351.12 ± 0.7426.07 ± 35.73
Week 61.07 ± 01.37 ± 0.540.79 ± 0.340.84 ± 0.40—
Week 91.57 ± 01.81 ± 0.830.83 ± 0.351.26 ± 0.600.35 ± 0
Other pre-specifiedConcentration of the Cytokine Interleukin-8 (IL-8)

The cytokine was quantitated using V-PLEX Human Proinflammatory Panel, a multiplex immunoassay kit developed by Meso Scale Diagnostics (MSD). A four-parameter logistic fit calibration curve was generated and used to calculate concentrations in tested samples. Analyses were performed at pre-treatment and 1 week following the first dose of drug and additionally at 2, 3, 6, and 9 weeks following the course 1 drug dose if feasible. The mean concentration of IL-8 in pg/ml was reported with a standard deviation. When only 1 participant analyzed, the standard deviation was reported as 0 (rather than undefined).

Time frame:
Pre-treatment (week 0), 1 week, 2 week, 3 weeks, 6 weeks and 9 weeks post-treatment
Reported as:
Mean · pg/ml
Concentration of the Cytokine Interleukin-8 (IL-8)
pg/mlStratum 1, Dose Level 1Stratum 1, Dose Level 2Stratum 1, Dose Level 3Stratum 2, Dose Level 2Stratum 2, Dose Level 3
Week 01.76 ± 05.88 ± 03.03 ± 0.804.91 ± 5.302.52 ± 1.18
Week 11.29 ± 0.615.86 ± 4.174.67 ± 1.994.40 ± 2.341.52 ± 1.01
Week 23.96 ± 0.604.27 ± 1.363.72 ± 1.302.74 ± 0.841.80 ± 0
Week 33.82 ± 03.66 ± 1.913.73 ± 1.423.23 ± 0.99217.42 ± 301.13
Week 63.30 ± 03.94 ± 1.463.39 ± 2.062.54 ± 0.87—
Week 93.86 ± 010.71 ± 11.422.87 ± 0.703.03 ± 1.560.66 ± 0
Other pre-specifiedTumor Mutation Burden Based on Whole Exome Sequencing of Tumor Tissue

Tumor mutation burden was defined as the number of somatic mutations per megabase. Average tumor mutation burden was reported with a standard deviation. When only one patient was analyzed, the standard deviation was reported as 0 rather than undefined.

Time frame:
Day 0 of treatment
Reported as:
Mean · mutations per megabase
Tumor Mutation Burden Based on Whole Exome Sequencing of Tumor Tissue
mutations per megabaseStratum 1, Dose Level 1Stratum 1, Dose Level 2Stratum 1, Dose Level 3Stratum 2, Dose Level 2Stratum 2, Dose Level 3
Tumor Mutation Burden Based on Whole Exome Sequencing of Tumor Tissue2.62 ± 1.033.82 ± 2.793.95 ± 2.340.97 ± 0.04.83 ± 5.94
Other pre-specifiedTumor Mutation Burden Based on RNA Sequencing of Tumor Tissue

Tumor mutation burden was defined as the number of somatic mutations per megabase. Average tumor mutation burden was reported with a standard deviation. When only one patient was analyzed, the standard deviation was reported as 0 rather than undefined.

Time frame:
Day 0 of treatment
Reported as:
Mean · mutations per megabase
Tumor Mutation Burden Based on RNA Sequencing of Tumor Tissue
mutations per megabaseStratum 1, Dose Level 1Stratum 1, Dose Level 2Stratum 1, Dose Level 3Stratum 2, Dose Level 2Stratum 2, Dose Level 3
Tumor Mutation Burden Based on RNA Sequencing of Tumor Tissue3.15 ± 0.923.33 ± 0.323.26 ± 1.35——
Other pre-specifiedMutation Burden Based on TCR Sequencing

Mutation burden as detected by comparing the TCR sequencing of tumor tissue and/or PBMC. Mean numbers of clonotypes were reported by time point with standard deviations.

Time frame:
Day 0 and Days 7, 14, and 21 after the start of treatment
Reported as:
Mean · Clonotyes
Mutation Burden Based on TCR Sequencing
ClonotyesStratum 1, Dose Level 1Stratum 1, Dose Level 2Stratum 1, Dose Level 3Stratum 2, Dose Level 2Stratum 2, Dose Level 3
Day 0———54688.25 ± 48633.55—
Day 7———159239.75 ± 47953.53—
Day 14———55328.25 ± 43692.86—
Day 21———127911.25 ± 135922.69—

Adverse events

Collected over Approximately 3 years after start of treatment. Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
Stratum 1, Dose Level 10/3 (0%)0/3 (0%)3/3 (100%)
Stratum 1, Dose Level 21/3 (33.3%)0/3 (0%)3/3 (100%)
Stratum 1, Dose Level 35/14 (35.7%)4/14 (28.6%)14/14 (100%)
Stratum 2, Dose Level 24/6 (66.7%)1/6 (16.7%)6/6 (100%)
Stratum 2, Dose Level 34/5 (80%)5/5 (100%)5/5 (100%)
Most frequent serious events
Showing 10 of 26
Most frequent serious events
EventStratum 1, Dose Level 1Stratum 1, Dose Level 2Stratum 1, Dose Level 3Stratum 2, Dose Level 2Stratum 2, Dose Level 3
Cytokine release syndromeImmune system disorders0/30/31/140/62/5
Infusion related reactionInjury, poisoning and procedural complications0/30/33/140/60/5
DysphagiaGastrointestinal disorders0/30/30/140/61/5
FatigueGeneral disorders0/30/31/140/61/5
Hepatic failureHepatobiliary disorders0/30/30/140/61/5
Allergic reactionImmune system disorders0/30/30/140/61/5
SepsisInfections and infestations0/30/30/140/61/5
Upper respiratory infectionInfections and infestations0/30/30/140/61/5
Aspartate aminotransferase increasedInvestigations0/30/31/140/61/5
Neutrophil count decreasedInvestigations0/30/30/140/61/5
Most frequent other events
Showing 10 of 84
Most frequent other events
EventStratum 1, Dose Level 1Stratum 1, Dose Level 2Stratum 1, Dose Level 3Stratum 2, Dose Level 2Stratum 2, Dose Level 3
White blood cell decreasedInvestigations1/33/39/143/63/5
Alanine aminotransferase increasedInvestigations1/32/312/145/65/5
Aspartate aminotransferase increasedInvestigations0/32/311/142/65/5
Lymphocyte count decreasedInvestigations2/32/37/142/64/5
AnorexiaMetabolism and nutrition disorders0/31/35/141/64/5
Neutrophil count decreasedInvestigations1/32/35/142/62/5
Platelet count decreasedInvestigations0/31/39/141/62/5
HypertensionVascular disorders0/30/30/140/63/5
Blood bilirubin increasedInvestigations0/30/33/140/63/5
HypophosphatemiaMetabolism and nutrition disorders0/30/34/143/63/5

Baseline characteristics

The one stratum 1, dose level 3 participant found to be ineligible after enrollment was excluded. Summary statistics for baseline characteristics are shown for eligible patients only (n=31).

Age, Continuous
Age, Continuous(Year)Stratum 1, Dose Level 1Stratum 1, Dose Level 2Stratum 1, Dose Level 3Stratum 2, Dose Level 2Stratum 2, Dose Level 3Total
Median4.2 (3.4 to 14.6)13.2 (8.9 to 21.9)9.7 (2.2 to 20.6)6.6 (1.4 to 10.4)8.8 (2.8 to 10.6)8.9 (1.4 to 21.9)
Sex: Female, Male
Sex: Female, Male(Participants)Stratum 1, Dose Level 1Stratum 1, Dose Level 2Stratum 1, Dose Level 3Stratum 2, Dose Level 2Stratum 2, Dose Level 3Total
Female1174518
Male2272013
Ethnicity (NIH/OMB)
Ethnicity (NIH/OMB)(Participants)Stratum 1, Dose Level 1Stratum 1, Dose Level 2Stratum 1, Dose Level 3Stratum 2, Dose Level 2Stratum 2, Dose Level 3Total
Hispanic or Latino1143211
Not Hispanic or Latino2193217
Unknown or Not Reported011013
Race (NIH/OMB)
Race (NIH/OMB)(Participants)Stratum 1, Dose Level 1Stratum 1, Dose Level 2Stratum 1, Dose Level 3Stratum 2, Dose Level 2Stratum 2, Dose Level 3Total
American Indian or Alaska Native100012
Asian001001
Native Hawaiian or Other Pacific Islander000000
Black or African American001012
White23104019
More than one race000000
Unknown or Not Reported002237
07

Study locations

11 sites
  • Children's Hospital Los Angeles
    Los Angeles, California 90026, United States
  • Lucile Packard Children Hospital Stanford University
    Palo Alto, California 94304, United States
  • Children's Hospital Colorado
    Aurora, Colorado 80045, United States
  • Childrens National Medical Center
    Washington D.C., District of Columbia 20010-2970, United States
  • Children's Healthcare of Atlanta
    Atlanta, Georgia 30322, United States
  • Lurie Childrens Hospital-Chicago
    Chicago, Illinois 60614, United States
  • Memorial Sloan Kettering Cancer Center
    New York, New York 10065, United States
  • Cincinnati Children Hospital Medical Center
    Cincinnati, Ohio 45229, United States
  • Children Hospital of Pittsburgh of UPMC
    Pittsburgh, Pennsylvania 15224, United States
  • St. Jude Children Research Hospital
    Memphis, Tennessee 38105, United States
  • Baylor College of Medicine
    Houston, Texas 77030, United States
08

References and documents

Study documents

  • Protocol and statistical analysis plan · Sep 23, 2022

Documents are hosted by the registry — open the source record to download them.

09

Registry details

Key details

Study ID
NCT03389802
Lead sponsor
Pediatric Brain Tumor Consortium
Collaborators
American Lebanese Syrian Associated Charities, Pyxis Oncology, Inc, Solving Kids' Cancer, Ty Louis Campbell Foundation, A Kids' Brain Tumor Cure Foundation, National Cancer Institute (NCI)
Responsible party
Sponsor
First posted
Jan 4, 2018
Start date
Mar 1, 2018
Primary completion
Sep 30, 2023
Completion
Jul 20, 2026
Results posted
Oct 10, 2024
Last update
Aug 13, 2026

Study contacts

Ira Dunkel
study chair · Memorial Sloan Kettering Cancer Center

Oversight

Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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