The Ai-Ling No.1 ("713") solution was made based on a well accepted prescription of traditional Chinese medicine, by Han Taiyuan in our hospital. The major ingredients were Arsenic and Mercury. The Ai-Ling No.1 solution had been used for treatment of neoplasms and leukemias. Sun Hongde et al reported that the Ai-Ling No.1 solution was used to treat 32 APL patients in 1992. That treatment generated a CR rate of approximately 65%. The Ai-Ling No.1 solution was then simplified into a single arsenic drug --Arsenic Trioxide. Based on our observations, the injected solution of Arsenic Trioxide was definitely effective in treating APL. Recurrent ATRA treated patients could be effectively treated with Arsenic Trioxide. This indicated that there was no cross drug resistance between Arsenic Trioxide and ATRA. This might be due to the fact that Arsenic Trioxide was not liposoluble and had a small molecular weight, which made it harder to generate cross drug resistance.
After the discontinuation of the Arsenic Trioxide therapy, all toxic side effects: the mild digestive symptoms, tingling of hands and feet, abnormalities in liver and renal function, the swelling of face and lower limbs, and the hydrothorax and ascitees, would disappear. Although Arsenic Trioxide was known to be more toxic than other arsenic compounds, we did not observe any serious toxic side effects, all adverse effects were reversible. This might be related to the fact that the daily dosage of Arsenic Trioxide was relatively low, and the drug was administered intravenously; it would be combined with hemoglobin inside the red blood cell, and directly removed from the kidney. Excessive arsenic might accumulate in the nails and hair of patients, it would be removed with the shedding of the nails and hair; total accumulation of arsenic would be reduced. In addition, each individual had a different sensitivity to the toxicity of arsenic.