The drug discovery process begins with observing how a disease changes biological processes in the body. Researchers look into what might be causing the disease, typically with the goal of identifying proteins in the body that might be involved in the disease process. They then form a hypothesis that inhibiting or activating a specific protein might potentially help to treat the disease. Proteins are the most common drug targets because they play various critical roles in the body, but drug targets can also include DNA or ribonucleic acid (RNA). A good target is one whose activity can be both linked to the way the disease works and how it can be modified by a drug.

During this phase, collaboration is key. Our scientists are involved in projects and strategic alliances with universities, charitable research organisations and other pharmaceutical companies, all working together to understand the disease and its causes. As of April 2024, we had 91 active research collaborations within the UK alone.³

We focus our efforts in core areas where we are best positioned to develop unique medicines for conditions; chronic inflammatory and autoimmune diseases, vaccines, oncology, pain, cardiovascular and metabolic diseases, and rare diseases.

Scientists begin searching for a molecule that will work on a specific disease target such as a gene or protein. Through ‘rational drug design’ scientists can create a molecule from scratch using cutting-edge chemistry and biotechnology. Alternatively, scientists can use ‘libraries’ of existing molecules, where thousands of potential candidates can be tested by automated systems.

Thousands of molecule combinations are screened in the hope of finding one or more promising candidates that show signs of potentially stopping or reversing a disease.

This is a critical stage where the molecule is built into a compound with different combinations tested to find out which formulation makes the molecule work most effectively.

Once the most promising molecule combination has been identified, it gets put through a series of rigorous tests to determine that it works, whether it works effectively, is stable and is reproducible.

The testing can be carried out in a number of ways, for example using computer simulations (in silico studies), cell-based tests (in vitro), and animal testing (in vivo studies) when absolutely necessary.

Then, pharmaceutical sciences teams work to turn the experimental molecules into safe and consistent medicines in preparation for clinical trials.

At this stage of the process, scientists aim to design and develop the most effective delivery mechanism for the molecule. How will the medicine reach its intended target? What is the optimal dose? Will it be a tablet, capsule, inhaler, cream, gel or liquid? How do we mass produce?

In preparation for clinical trials, our Devices Centre of Excellence in Cambridge, UK develops medical devices for the delivery of medicines which cannot be taken orally, such as auto-injectors or injector pens.

Medicines need to be tested to check they are safe, and are effective at treating or preventing the disease they were developed for, prior to applying for a licence to make them available to the public.

There are four stages of testing investigational medicines in human subjects:⁴

Phase 1 – A small number of healthy volunteers
Phase 2 – A larger group of people with the disease
Phase 3 – Typically several thousand patients
Phase 4 – Ongoing monitoring during the lifespan of the medicine

Trials are often run in partnership with universities, hospitals, general practitioners and the government.

Information about clinical trials that Pfizer conducts is publicly available on www.clinicaltrials.gov and www.clinicaltrialsregister.eu.

Results from clinical trials are submitted to regulatory agencies to obtain a licence prior to it being made available to patients. Licensing is needed to confirm the quality, efficacy and safety of a medicine. Whilst no medicine is risk-free, a licence demonstrates that all the proper checks have been carried out and the potential benefits of the medicine are believed to outweigh the risks.

In the UK, licences are granted by The Medicines and Healthcare Products Regulatory Agency (MHRA).

In order for medicines to be made available to UK patients through the NHS, it is necessary to gain market access and reimbursement after licensing. This is achieved through health technology assessment (HTA) through reviewing clinical effectiveness and cost effectiveness of a medicine. In the UK, examples of HTA agencies are the National Institute for Health and Care Excellence (NICE), All Wales Medicines Strategy Group (AWMSG) and the Scottish Medicines Consortium (SMC).

The UK is home to Pfizer’s Global Regulatory Affairs, where licensing submissions for over 175 markets across the globe are managed.⁵

Once a medicine is licensed and has UK market access approval, it can now be manufactured at scale in preparation for supply to the NHS.

At Pfizer we manufacture many of our own medicines, but also rely on third parties to manufacture and warehouse medicines within the UK. Our manufacturing follows European Good Manufacturing Processes (GMP) and has a dedicated team based in the UK to ensure Pfizer medicines are produced to the highest standards for UK patients.

Our Material Characterisation Team, based in Sandwich, UK, specialise in safety testing during the manufacturing process. This team ensures that suppliers' and Pfizer's own manufacturing processes, across the globe, meet exacting standards.

 

Packaging and transporting medicines across the UK, and around the world, involves significant investment to maintain high quality supplies and to be able to respond to demand.

Temperature-controlled shipping containers are used so that medicines arrive at their destination in perfect condition – from large airline shippers containing thousands of doses, to a small container in a car, heading for a remote mountainous location.