1. Given the current technology, I believe that pre-clinical testing in animal models is necessary prior to human clinical trials. An effort is being made to reduce or replace animal use, but I believe its a few years off and not accessible or cost-efficient to everyone yet. Read-across-based Structure Activity Relationship (RASCAR) and organs-in-chips are a couple of alternatives being developed. Although animal species are not an exact match to the human species, I believe there is still value in a whole, living system rather then developing a drug 100% in-vitro.
From an ethical standpoint I see the issue and have experienced it first-hand; I spent 15 years conducting pre-clinical research. In my experience, the use of every animal was taken seriously and scrutinized. Animal Use Protocols (AUPs) are reviewed extensively by an Institutional Animal Care and Use Committee (IACUC), which is similar to an Institutional Review Board (IRB) approval. In my opinion, I feel that human clinical trials have a greater reinsurance of safety and efficacy, having been first in pre-clinical trials, which include animal models.
For what it is worth, I have a Bachelor of Science, in Veterinary Technology, and dedicated 10 years of my career in small animal practices. When leaving the veterinary practice to begin my career in pharmaceuticals (LVT salary just doesnt pay the bills) the veterinarian I worked for said I cant believe you could leave and go experiment on animals, I could never do that. I think its easy to forget that even our pets benefit from animal research; studies are 100% conducted in animals, to also develop veterinary medicines.
2. Historically speaking the regular use of animals in scientific testing is a product of the tragedies like Elixir Sulfanilamide, which caused the death of 107 people, mostly children and led to the passing of the Food, Drug and Cosmetic Act of 1938. This act mandated that a drug be proven safe before being sold for public use. The first stage in research and development of a new medical product is preclinical testing. This involves testing of living material to understand the disease process and how the new proposed product will work. This living material can come in the form of human or animal cultured cells or live animals. There are many things in drug and medical device testing that can only be understood in animals before it is safely tested in humans. Toxicology studies are an example of this; observing a products effects in animal models are needed to better predict and translate the processing of product in a human body. Without this type of preclinical testing it is not safe to test it in humans. Toxicology testing can help scientists predict its outcomes in the human body through tests like absorption, distribution, metabolism, and excretion (ADME), potential chronic effects and potential for genetic motivated toxicology differences.
From an ethical stand point, I do acknowledge that breeding animals specifically for research is a cruel way to treat a living being but is a crucial part of ensuring the safety of humans and reducing the suffering of our species. Many groups and organizations have pushed back on the use of animals for research, in not only medical products but also chemicals used in a variety of household and cosmetic products. Until technology is able to test effectiveness and safety in non-living models we will need to continue test on living animals to ensure to the best of our ability its potential safety and side effects in human volunteers. A bioanalytic tools company is making some strides in this direction. HREL Corporation, has patented a line of microfluidic devices (cellular based) that simulate pharmacokinetic interactions among multiple tissues and organs. As technologies advance, I believe we will see a shift in biomedical research to this type of safety testing as it is more ethical, most likely easier to maintain and more cost effective than live animal model testing.