* Source: Asan Medical Center, Korea Institute of Radiological and Medical Science, CHA hospital, college of veterinary medicine, SNU, KIST, Biotoxtech, Inje University, Catholic University of Korea, Handong University


Molucular Weight : 395.6
Molecular Structure : Diamond Structure


2,4,6,8,9,10 – Hexaoxa – 1,3,5,7 – tetraarsatricyclo[,7]decane

As4O6 (Arsenic hexaoxide) API


<TetraAs tablet form>

Clinical Drug


<TetraAs® capsule (5mg) form>

Application progress of As as a drug (flow)


  1. Arsenic and arsenic compounds have used as a medicine or a toxin for 2000 years.
  2. An ointment containing arsenic is used as a therapeutic agent for dental disease, psoriasis, syphilis,
    and rheumatic illness
  3. Ancient Hippocrates age: : Realgar (AS2S3) and orpiment (AS2S2) were used as a drug for ulcers, pest, malaria and various cancers
  4. Other records that demonstrate the use of arsenic:
    – India: Pregnant women have taken it to improve the health of their fetus
    – Alps alpine region: Has been taken to invigorate vital energy
    – India: Has been used as a dermal ointment
    – China: Noted doctors including Jang Jung Gyeong, Pyeonjak, and Hwata used it as a drug for incurable diseases
    – Korea: The noted doctor, Heo Jun, used arsenic to treat various incurable diseases
  5. Used broadly as a medicinal product (to treat diseases) since the 18th century
    Potassium carbonate solution of AS2O3 developed by Thomas Fowler (U.K) in 1786: Used as a drug for rheumatism, seizures (epilepsy), ulcers, and indigestion. In 1910, the founder of chemotherapy, Paul Ehrlich (toxin) invented salvarsan using arsenic (No. 606) and used it as a drug for syphilis. An organic arsenic compound, malarsoprol, is currently being prescribed to treat trypanosomiasis invading CNS. From 1940s, it was used as a therapeutic agent for CML until new treatment for CML was developed.
  6. Reason for limited use of arsenic – ① Development of radiation therapy and other chemotherapies ② Known as a toxic substance with carcinogenic effects especially when used for long periods of time
  7. In 1992, Harbin medical University, China – Published the arsenic therapy for APL in an academic symposium in China
    – Since Shen et al in China (Blood, 89; 3354-3360, 1999) reported that AS2O3 injections were effective in treating retinoic acid resistance in acute promyelocytic leukemia, a number of hospitals and researchers attempted to treat APL and various solid cancers with AS2O3
  8. In 1996, Shanghai Second medical University, China published in American Society of Hematology
  9. In 2000, U.S. FDA approved AS2O3 as an orphan medicinal product for the treatment of acute promyelocytic leukemia to all-trans retinoic acid
    – Currently, arsenic is being studied in several countries including Korea and China
  10. In Korea, CHEMAS has patent right on As4O6 and is taking a step to do clinical trial on As4O6
As anti-cancer drug


  1. China – It was reported that AS2O3 is effective in treating APL in 1992
  2. U.S. FDA approved AS2O3 as an orphan medicinal product for the treatment of APL in 2000
    – Cephalon (www.Cephalon.Com) – “TRISENOX” injections for intravenous administration
  3. Limited use of arsenic’s advantages.


  1. U.S. FDA approved As4S4 as a therapeutic agent for CML. (2002)
  2. It cannot be used for a long period of time because of its toxicity and its therapeutic effect on various solid cancers has not been proved sufficiently against leukemia

As4O6 (TetraAs)

  1. Solved the toxic problems and adverse effects of arsenic compounds
  2. Not accumulated in the human body and excreted within short period of time
  3. Almost no side effects in spite of long-term use
  4. Safety and effectiveness has been verified in pre-clinical trials (toxicity test) in Biotoxtech and phase 1 clinical trial in Asan Medical Center
  5. Huge therapeutic possibilities against various cancers
  6. Efficacy enhanced when used with other conventional cancer treatments
  7. Successfully completed pre-clinical and phase 1 clinical trials