Alexander Fleming discovered penicillin in 1928, but it wasn’t used in human medicine until the 1940s. This penicillin, penicillin G, had to be administered by injection. A modification, phenoxymethylpenicillin, (penicillin V) was developed for use in 1951. This penicillin (penicillin V) could be administered by mouth.
Subsequently, it was found that the key to penicillin activity was the beta lactam ring, a 5 carbon structure. When a side chains were added to the beta lactam ring, it led to the discovery of newer antibiotics with the ability to treat infections that had become resistant to the original penicillins. Since then a number of important antibiotics have been developed by modifications of the original ring structure.
In many areas of drug therapy where an initial discovery has been made, scientists have found that a minor molecular modification can improve the activity of the drug, or reduce the frequency or severity of the side effects. The problem is the timing and cost for the development of a new drug. According to the Congressional Budget Office, “The expected cost to develop a new drug—including capital costs and expenditures on drugs that fail to reach the market—has been estimated to range from less than $1 billion to more than $2 billion,” and the estimated time to bring a new drug to market is 10 years. PhRMA, the trade association of pharmaceutical manufacturers gives the decade estimate.
Right now we are dealing with what may be a major convergence of sciences. One is the Food and Drug Administration’s approval of Leqembi (lecanemab) to treat early-stage Alzheimer’s disease. Alzheimer’s is a terrible disease. Although it’s commonly associated with memory loss, it slowly destroys memory and thinking skills and, eventually, the ability to carry out the simplest tasks. In the later stages, people with Alzheimer’s disease lash out for no clear reason. They may get upset or angry easily. They may curse, hurl insults, or scream. They might even throw things or resist caregivers by pushing and hitting. One dentist, whose practice includes Alzheimer’s patients, was severely bitten. There is no cure for Alzheimer’s disease.
But, on July 7 the Food and Drug Administration gave full approval to Leqembi (lecanemab-irmb), the first drug to slow progression of mild to moderate Alzheimer’s disease. Traditional treatments could only moderate the symptoms, but to affect the underlying cause of Alzheimer’s, the deposition of amyloid plaques, in the brain. It is not a cure, and can not stop or reverse the progression of Alzheimer’s Disease, but it is the first drug that acts on the underlying cause. With further study, Leqembi may be as significant as the discovery of penicillin G: a starting point which might even lead to a cure.
The hope comes from the conjunction of a drug that affects the cause of a disease, and computer developments that may speed up developments of newer drugs. AI can’t create new ideas – that’s a strictly human monopoly, but it can search what’s known and apply these knowns to existing problems. AI is used in hearing aids to determine what sounds you’re interested in and reduce the volume of unwanted sounds. In education it may be possible to analyze a person’s learning style and prepare individualized lesson plans. In agriculture, AI may be able to analyze irrigation schedule and reduce water needs. In drug development it can suggest molecular modifications in the hope of developing new drugs more rapidly and economically than current methods.
Just about every drug company and tech company is working with AI to develop new drugs or modify old ones. IBM, whose Watson defeated three Jeopardy champions has split off its health division to form Merative, which can do clinical analysis to optimize both diagnosis and treatment. Merck’s website says it’s AI applications ...”can be used to design new starting points for drugs by learning from existing drugs and exploring larger chemical spaces than humans or standard computational methods can.”
Pfizer (insights.pfizer.com) describes how AI and supercomputers can accelerate development of new drug molecules and, not coincidentally, raise Pfizer’s stock price (Pfizer stock has dropped so far this year, but then so has the entire market.) AstraZeneca claims, “Data science and artificial intelligence (AI) are embedded across our R&D to enable our scientists to push the boundaries of science to deliver life-changing medicines.”
Regarding Alzheimer’s Disease, this may be a wonderful confluence between a drug that may show a new direction, and a technology that may help follow the lead.
Sam Uretsky is a writer and pharmacist living in Louisville, Ky. Email sam.uretsky@gmail.com
From The Progressive Populist, August 15, 2023
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