Gene and cell therapies: a new class of medicine

Advanced Therapy Medicinal Products (ATMPs) represent a relatively new and complex class of medicines based on genes, cells, and tissues. Unlike conventional pharmaceuticals, which are typically chemically synthesised small molecules or biologics produced by uniform cell lines, ATMPs use living cells or genetic material to treat or prevent diseases. This rapidly evolving field aims to address the root cause of certain genetic disorders and cancers rather than simply managing symptoms. Because they involve altering the body's fundamental biological building blocks, ATMPs are subject to intense scientific scrutiny and face unique manufacturing, pricing, and access challenges.

Understanding the Types of ATMPs

Regulators generally classify ATMPs into four broad categories. Gene therapies introduce genetic material into a patient's cells to replace, correct, or silence faulty genes. This genetic modification can happen directly inside the body (*in vivo*) or by extracting cells, modifying them in a laboratory, and returning them to the patient (*ex vivo*). Somatic cell therapies use living cells to trigger a biological response; a well-known example is CAR-T cell therapy, where a patient's own immune cells are reprogrammed to target cancer. Tissue-engineered products combine cells with natural or synthetic scaffolds to repair or regenerate damaged tissues, such as engineered skin for severe burns. Finally, combined ATMPs incorporate a medical device alongside the biological component, such as a cellular implant. Because these products contain living entities, they cannot be standardised in the same way traditional pharmaceutical tablets are.

Why These Therapies Command High Prices

ATMPs are frequently among the most expensive medicines in the world, sometimes costing millions of dollars for a single administration. This cost is largely driven by manufacturing complexity. Producing living cells requires highly specialised, sterile cleanroom facilities. Processes are often tailored to individual patients, making mass production difficult and labour-intensive. Furthermore, developing these therapies involves intricate clinical trials and highly specialised supply chains that must maintain strict temperature controls to keep the living cells viable during transport. For gene therapies, the "vectors" (often modified viruses) used to deliver genetic material into cells require their own complex manufacturing processes. Because many ATMPs are intended as one-time, potentially curative treatments, manufacturers must recoup years of research and development costs through a single payment rather than over a lifetime of daily prescriptions.

How Regulators Assess Safety and Quality

Because ATMPs permanently alter cells or genetic material, regulatory assessment is uniquely rigorous. Agencies like the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA) require extensive preclinical data to ensure the altered cells do not behave unpredictably, such as multiplying uncontrollably or integrating into the wrong part of the genome. A significant regulatory challenge is determining the "potency" of living cells—proving that each batch of cells is consistently active enough to work as intended. In Europe, the EMA has a dedicated Committee for Advanced Therapies (CAT) that specifically evaluates these products. Due to the permanent nature of genetic edits and the longevity of living cells, regulators frequently require developers to conduct long-term follow-up studies, sometimes monitoring patients for many years after administration to track durability and late-emerging side effects.

Global Access and Reimbursement Challenges

The high cost of ATMPs creates significant access challenges for health systems globally. Traditional reimbursement models are designed for chronic medications paid per dose or per month, not for one-time, multi-million-dollar interventions. Health systems are increasingly experimenting with novel pricing models, such as outcomes-based agreements, where payment is only required if the therapy successfully maintains remission over a specified period. However, administering these therapies also requires specialised medical infrastructure, meaning they are initially available only at a limited number of hospitals. In many countries, including South Africa, regulators like SAHPRA must build the specialised capacity required to assess these highly complex products, while health systems grapple with how to finance them. For patients and providers trying to understand the availability and regulatory status of both traditional medicines and emerging therapies, tools like HealthSA provide a way to search for registered medicines and their pricing.