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Antineoplastons (PDQ®): Complementary and alternative medicine - Health Professional Information [NCI] - General Information


Antineoplaston A was further purified and yielded antineoplastons A1, A2, A3, A4, and A5. These mixtures of 7 to 13 peptides were patented in 1985.[6]In vitro tissue culture studies and in vivo toxicity studies in animal models were performed for antineoplastons A1 through A5. According to the developer, each individual fraction had a higher level of antitumor activity and lower toxicity level than antineoplaston A.[2]

Phase I trials of this antineoplaston group in patients with various advanced cancers showed A2 as contributing to the highest tumor response rate, so it was selected for further study.[2]

The active compound in A2 was found to be 3-phenylacetylamino-2,6-piperinedione, which was named antineoplaston A10.[7] From antineoplaston A10, three other compounds have been derived:

  • AS2-5, which is phenylacetylglutamine (PAG).
  • AS2-1, which is a 4:1 mixture of phenylacetic acid (PA) and PAG.
  • A5, which is PA and an aromatic fatty acid.

Other antineoplastons (A3, A4, A10-1, AS5) were added to this group after further studies.[2,3,4]

There have been no independent analyses of which amino acids comprise the antineoplastons used in any of the reported studies.

Antineoplastons are administered by different methods. Antineoplaston A has been given intravenously, intramuscularly, rectally, topically, intrapleurally, and by bladder instillation.[8] Presently, antineoplastons A10, AS2-5, AS2-1, A2, A3, and A5 are given orally or by injection.[8,9,10,11,12,13,14,15,16,17,18,19,20]

Critical opposition to antineoplaston therapy and its developer have appeared in the published literature.[4] A basic criticism of the developer's work is that although he has put forth a theory of peptides inducing cell differentiation, there is no published evidence that he has experimentally tested the hypothesis that information-bearing peptides could normalize cancer cells. Although some articles attempt to demonstrate that antineoplastons (specifically, antineoplaston A10) can bind to DNA at certain sites, this is an extrapolation from three-dimensional molecular models of DNA and A10 and does not demonstrate that this binding actually occurs.[21,22,23]

Other criticism focuses on the form of antineoplastons. Although the active fraction, antineoplaston A10, is insoluble in aqueous solutions, the developer has stated that it is present in body fluids.[4]

Antineoplastons AS2-5 and AS2-1 are derived from A10. Antineoplaston AS2-5 is PAG, and AS2-1 is a 4:1 mixture of PA and PAG. Because it is a strong acid, PA would exhibit cytotoxicity in vitro if in high enough concentration and not neutralized.[4]

The active component of antineoplaston A10 is 3-phenylacetylamino-2,6-piperidinedione. Reagents necessary for the synthesis of this antineoplaston compound are readily available internationally from any chemical supply company.[24] The developer retains patents on antineoplaston compounds and their use when administered pharmaceutically to inhibit the growth of neoplastic cells.[6,25]


WebMD Public Information from the National Cancer Institute

Last Updated: February 25, 2014
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
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