Terminated early by the Sponsor due to business reason.

This phase I/II trial investigates the side effects and how well CD24Fc works in treating immune related adverse events in patients with solid tumors that have spread to other places in the body (advanced). CD24Fc may prevent autoimmune reactions due to the tissue damage induced by cancer treatment. CD24Fc binds to injured cell components and prevents inflammatory responses. CD24Fc also acts to turn off the immune system after it has been activated ("immune checkpoint"). Adding CD24Fc to standard treatment may shorten the recovery time and reduce the severity of side effects from immunotherapy.

PRIMARY OBJECTIVES:

I. To determine the safety and tolerability of CD24 extracellular domain-IgG1 Fc domain recombinant fusion protein CD24Fc (CD24Fc) in patients with advanced solid tumors who developed debilitating immune-related adverse events (irAEs) from immune check point inhibitors (ICIs). (Phase I) II. To determine if CD24Fc shortens the recovery time of irAE and increases the recovery rate of irAE in cancer patients with grade (G)2 or 3 irAEs. (Randomized phase II)

SECONDARY OBJECTIVES:

I. Time to irAE reduction by at least 1 grade. (Phase I) II. Time to all irAEs reduced to grade =< 1. (Phase I) III. Time to resume ICI treatment. (Phase I) IV. Recovery rate (as defined by reduction of irAE by one grade) at day (D)42. (Phase I) V. To estimate the time to all irAEs reduced to =< 1. (Randomized phase II) VI. To record the use of steroids (drug, dose, duration) and other treatment for irAE. (Randomized phase II) VII. To record the time to resume ICI treatment. (Randomized phase II) VIII. To estimate the preliminary overall response rate (ORR), progression free survival (PFS), and 1-year overall survival (OS) after treatment with or without CD24Fc. (Randomized phase II) IX. To determine if CD24Fc treatment changes the levels of inflammatory markers in the plasma. (Randomized phase II)

OUTLINE:

PHASE I: Patients receive CD24Fc intravenously (IV) over 60 minutes on days 1, 14, and 28 with standard of care (i.e., steroids per treating physician and best supportive care) in the absence of disease progression or unacceptable toxicity.

PHASE II: Patients are randomized to 1 of 2 arms.

ARM I: Patients receive CD24Fc IV over 60 minutes on days 1, 14, and 28 in addition to standard of care treatment for irAE in the absence of disease progression or unacceptable toxicity.

ARM II: Patients receive placebo IV over 60 minutes on days 1, 14, and 28 in addition to standard of care treatment for irAE in the absence of disease progression or unacceptable toxicity.

After completion of study treatment, patients are followed up at days 42 and 60 and then every 3 months for up to 1 year.

Inclusion Criteria:

• Ability to understand and willingness to sign an informed consent form

• At least 18 years of age

• Histologically confirmed advanced solid tumors

• Patients must have grade 2 or 3 irAEs from at least one ICI-containing regimen. Both newly emerging and persistent irAEs are allowed. Systemic steroid therapy or any other form of immunosuppressive therapy for irAEs is allowed. The specific irAEs are

  • Grade 2-3 diarrhea/colitis: Patients with >= 4 stools per day or moderate-severe increase in ostomy output compared to baseline but not life-threatening diarrhea
  • Grade 2-3 pneumonitis: Mild to moderate (grade 2) or severe (grade 3) symptoms (including hypoxia, shortness of breath, requiring oxygen) but not life-threatening respiratory compromise requiring urgent intervention (e.g., tracheostomy or intubation)
  • Grade 2-3 renal irAE: Creatine increased between 1.6-6.0 x upper limit of normal (ULN) or =< 3.0 x baseline if baseline was abnormal, estimated glomerular filtration rate (eGFR) or creatinine clearance >= 15 ml/min/1.73m^2 but not life-threatening consequences or requiring dialysis
  • Grade 2-3 Hepatic irAE: AST/ALT/ALP levels 3-20 x ULN, and T bilirubin increased <5 x ULN
  • Grade 2-3 skin rash: moderate (10-30% body surface area, BSA) to severe (> 30% BSA) but not life-threatening skin lesions or Stevens-Johnson syndrome

• Eastern Cooperative Oncology Group (ECOG) performance status < 2

• Life expectancy of >= 3 months at the time of enrollment

• Pretreatment absolute neutrophil count (ANC) >= 1,000/uL obtained within 14 days prior to 1st dose of treatment

• Pretreatment hemoglobin >= 8 gm/dL obtained within 14 days prior to 1st dose of treatment

• Pretreatment platelet count of >= 75,000/uL obtained within 14 days prior to 1st dose of treatment

• Female subjects who are of non-reproductive potential (i.e., post-menopausal by history - no menses for >= 1 year; OR history of hysterectomy; OR history of bilateral tubal ligation; OR history of bilateral oophorectomy). Or, female subjects of childbearing potential must have a negative serum or urine pregnancy test within 72 hours prior to the first study drug administration

• Male and female subjects who agree to use highly effective method of birth control (e.g., implants, injectables, birth control pills with two hormones, intrauterine devices [IUDs], complete abstinence or sterilized partner, and female sterilization) and a barrier method (e.g., condoms, vaginal ring, sponge, etc.) during the period of therapy and for 90 days after the last dose of study drug

Exclusion Criteria:

• Prior CD24Fc therapy
• Any known active hepatitis B (HBV), hepatitis C (HCV), or human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS)-related illness, including patients who have an active infection requiring systemic therapy. History of COVID-19 or known asymptomatic carrier of SARS-CoV-2 virus is allowed
• Pregnant or lactating women
• Any medical condition including additional laboratory abnormalities, or psychiatric illness that would, in the opinion of the investigator, prevent the subject from participating and adhering to study related procedures
• Any known severe bacterial, fungal, or viral infection that in the opinion of the investigator would interfere with patient safety or compliance on trial within 2 weeks prior to enrollment
• Patients with concomitant proarrhythmic medications
• Patients with heart failure in New York (NY) Heart Association stage IV
• Any grade 4 irAE symptoms and Common Terminology Criteria for Adverse Events (CTCAE) version (v)5.0 grade 4 toxicity
• AST, ALT, gamma glutamyl transpeptidase (GGT), or ALP > 20.0 x ULN regardless of baseline
• Blood bilirubin >5.0 x ULN regardless of baseline
• Creatinine > 6.0 x ULN or creatinine clearance <15 ml/min/1.73m2
• Urine: Anuria < 140 ml in 24 hours
• Electrolytes hyponatremia, sodium < 120 mmol/L
• Hypokalemia, potassium < 2.5 mmol/L
• Creatine kinase (CPK) > 10.0 ULN
• Electrocardiogram (ECG): Prolonged QT interval >= 480 mS, corrected by Fridericia's formula. Torsade de pointes; polymorphic ventricular tachycardia; signs/symptoms of serious arrythmia