First Patient Dosed in EO2401 Clinical Trial for Adrenal Tumors

Early this week, clinical-stage biopharmaceutical company Enterome announced that the first patient was dosed in a Phase 1/2 clinical trial. The SPENCER trial will evaluate EO2401 as a potential treatment for patients with adrenal tumors, particularly pheochromocytoma and adrenocortical carcinoma. Additionally, during the trial, researchers will analyze whether EO2401 can be used in conjunction with an immune checkpoint inhibitor (CPI) for ultimate patient benefit.


Enterome utilized their proprietary OncoMimic platform to develop EO2401. But what are OncoMimics? Basically, these are microbiome-derived peptide antigens that imitate tumor antigens. By combining three OncoMimics from cancers like glioblastoma or pheochromocytoma, EO2401 drives the immune system to react and attack the tumor.

Researchers will test EO2401 in the Phase 1/2 SPENCER trial. The first patient was recently dosed. However, up to 72 patients with adrenal tumors will be dosed throughout the course of the study. During the trials, researchers will analyze the safety, efficacy, tolerability, and immunogenicity (ability to provoke an immune response) of EO2401.

Right now, there are few treatments for patients with adrenal tumors. In fact, surgery is usually the only option following diagnosis. As a result, additional treatments are needed to fulfill this unmet need.

Adrenal Malignancies

Adrenocortical Carcinoma

Doctors are unsure of the cause of adrenocortical carcinoma, a rare adrenal cancer causing excess hormone production. Patients often survive around 3-4 years following diagnosis. However, for patients with advanced adrenocortical carcinoma, the prognosis is poor. Survival rate in this group is less than 15% for a 5-year period.

Generally, patients will experience abdominal lumps, a feeling of fullness, and abdominal and back pain. However, other symptoms depend on which hormones are overproduced:

  • Cortisol
    • High blood pressure
    • Deepening voice
    • Genital inflammation
    • A round, full face
    • Unintended weight gain
    • High blood sugar
    • Muscle pain and weakness
    • A fatty lump on the neck
  • Testosterone
    • Irregular menstrual cycles
    • Unintended weight gain
    • Random vaginal bleeding
    • Lowered sex drive
    • Male breast tissue growth
    • Impotence
  • Aldosterone
    • Frequent urination
    • Insatiable thirst
    • Muscle pain and weakness
    • High blood pressure
    • Acne
    • Female balding
    • Loss of menstrual cycle


Many pheochromocytomas, a rare adrenal tumor, are benign. However, these rare tumors can cause health problems throughout the body. A pheochromocytoma often appears randomly, although 25-35% of cases are attributed to gene mutations. The tumor appears from chromatin cells, which release hormones called catecholamines. These tumors affect males and females equally, and generally occur between the ages of 30 and 50.

While some patients will never experience symptoms, those who do might experience:

  • Dizziness
  • Headaches
  • Pale skin
  • Chest and abdominal pain
  • Nausea and vomiting
  • Excessive sweating
  • Gastrointestinal changes (diarrhea, constipation)
  • Muscle weakness
  • Fatigue
  • High blood pressure
  • Anxiety
  • Abnormal heartbeats
Jessica Lynn

Jessica Lynn

Jessica Lynn has an educational background in writing and marketing. She firmly believes in the power of writing in amplifying voices, and looks forward to doing so for the rare disease community.

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