HKU Develops the World's First Oral Arsenic Trioxide Drug for Leukemia
After more than two decades of research, the LKS Faculty of Medicine, the University of Hong Kong, has developed a fully oral treatment regimen known colloquially as "AAA," consisting of oral arsenic trioxide, all-trans retinoic acid (ATRA) and ascorbic acid. It has shown excellent efficacy against acute promyelocytic leukemia (APL), improving patient survival and effectively reducing early mortality caused by APL-related complications.
The active ingredient in this oral drug developed by HKU Medicine is arsenic trioxide (commonly known as arsenic / pi-shuang). In Hong Kong it has now replaced hematopoietic stem cell transplantation as the main safe and effective treatment for leukemia. Currently all APL patients in Hong Kong can be prescribed oral arsenic trioxide at public hospitals. To date more than 430 patients have benefited, and over 90% of them have been cured.
This drug became the first medicine from China to obtain patents in Europe, America and Japan. It has recently received certification from the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA), allowing it to be rolled out in Europe, America and elsewhere.
The clinical use of arsenic to treat leukemia first began in mainland China, but previously it mainly took the form of arsenic trioxide injections administered by intravenous infusion in hospitals. Arsenic trioxide is highly toxic, and the safety of oral administration had long been unresolved. After years of exploration, Chinese medical workers gradually worked out a safe oral dose and developed an oral regimen, benefiting a large number of patients.
The earliest recorded medicinal use of arsenic appears in Rihuazi Bencao (Materia Medica of Rihuazi), compiled by the folk physician Rihuazi during the Wuyue regime of the Five Dynasties and Ten Kingdoms period. The ancients called it pi-shi (arsenolite), or yellow arsenic, xin-pi, xin-shi, etc. Rihuazi Bencao records that it treats malaria and kidney qi. Ancient pi-shi was a processed product of natural arsenic-bearing minerals such as arsenolite, arsenopyrite or realgar; the refined sublimated product of pi-shi is arsenic (pi-shuang), a highly toxic white powder.
Traditional Chinese medicine holds that arsenic is pungent in taste, extremely hot in nature, and highly toxic, entering the lung and liver meridians. Taken internally it expels phlegm and stops wheezing, and attacks toxins and counteracts cancer; applied externally it erodes sores, removes putrid tissue, attacks toxins and kills parasites. It is commonly used to treat scrofula (lymph node enlargement), dental gingivitis, hemorrhoids, ulcers with non-sloughed necrotic tissue, scabies and tinea itching, cold-phlegm asthma, malaria and dysentery.
Modern pharmacological research shows that arsenic has antihistaminic, antiasthmatic, bactericidal, hematopoietic and corrosive effects. Long-term small-dose absorption strengthens anabolism, promotes protein synthesis, thickens adipose tissue, improves skin nutrition, strengthens bone growth, and promotes bone marrow hematopoietic function.
However, because this substance is extremely toxic and medical accidents are very easy to occur, it has basically been withdrawn from the market in modern times, and only a few hospitals have carried out internal research on using arsenic to treat leukemia and other cancers. Besides its good efficacy against acute promyelocytic leukemia, arsenic also works well against early-stage cervical cancer and skin cancer. Contemporary medical workers are also conducting research on using arsenic to treat lung cancer, liver cancer and other malignancies.
Reports show that using the "Sanpin Yichang Qiang" regimen containing arsenic to treat early cervical cancer — a total of 210 cases — achieved a short-term cure rate as high as 97.15%; after 3–5 years, 188 cases were cured without recurrence. The effective rate is higher than that of surgical treatment, and this regimen can preserve the physiological and reproductive functions of young and middle-aged patients, giving it an advantage over surgery.
Another report describes taking 10 g of arsenic and 50 g of starch, adding an appropriate amount of water, kneading the mixture and twisting it into thread-like strips, then letting them air-dry. After disinfecting the area around the cancerous focus, one medicinal strip was inserted every 0.5–1 cm, reaching the base of the tumor in a ring shape, followed by external application of "Yixiao Gao" (made from 50 g cinnabar, 150 g calamine, 50 g borneol, 500 g talcum powder and 100 g starch, mixed into a paste with an appropriate amount of sesame oil). A total of 22 cases of various skin cancers were treated; after 4–90 days of treatment all were cured, and follow-up of 1–5 years showed no recurrence.
In the future, arsenic may play a role in the treatment of more cancers.