A small molecule medicine is what most people think of when they imagine a medicine. These medicines typically come in the form of a tablet or capsule and are usually taken by mouth. These medicines play essential roles in the treatment of different diseases and are indispensable in providing patients, caregivers and health care providers with the tools necessary to achieve improved health outcomes. Despite the important advantages small molecule medicines offer in the treatment of many illnesses, government price setting provisions in the recently passed Inflation Reduction Act (IRA) could result in fewer of these medicines being developed for patients.
Under the law, small molecule medicines can be selected for price setting seven years after they are U.S. Food and Drug Administration (FDA) approved, with the government set price taking effect two years later. This is substantially earlier in their lifespan than their average effective patent life of 13 to 14 years, consequently discouraging companies from investing in the R&D of these medicines. Biopharmaceutical companies are already taking the IRA into account when making tough decisions about R&D projects. In a survey of biopharmaceutical companies, 63% said they expect to shift R&D investment away from small molecule medicines as a result of the IRA.
As we look at the impact of the IRA on small molecule medicines, here are four things to know:
1. Small molecule medicines can reach therapeutic targets inside cells.
To treat a disease, a medicine must be able to reach a specific therapeutic target which in most cases is a protein associated with a specific biological process that can cause disease if it isn’t functioning properly. Due to their smaller size, simpler structure and lower molecular weight, small molecule medicines have the ability to cross cell membranes with relative ease. These characteristics make it easier for small molecule medicines to reach their therapeutic targets inside cells to facilitate clinical benefit. It is for these reasons, for example, that small molecule targeted therapies have become such a critical part of the treatment arsenal against cancer, due in large part to the ability for these medicines to reach targets inside cells, where cancer originates.
2. Small molecule medicines can cross the blood-brain barrier.
While the blood-brain barrier plays a critical protective role in the body by regulating which substances can pass from the blood into the brain to protect the central nervous system, it can also serve as a formidable barrier that can inhibit delivery of medicines for diseases whose therapeutic targets are inside the brain. The unique ability to cross the blood-brain barrier allows small molecule medicines to serve a critical role in the treatment of health conditions impacting the central nervous system, such as mental illness, stroke, epilepsy, various neurodegenerative diseases such as Alzheimer’s disease, dementia, Parkinson’s and many more.
3. Small molecule medicines provide greater flexibility and convenience for health care providers, patients and their caregivers, improving treatment adherence.
Small molecule medicines come in a variety of different dosage forms like pills, tablets or capsules, which make them easier to take and are an often-preferred method for patients. A dosage form is the physical form a medicine takes to deliver an effective dose of the medicine’s active ingredient to the patient. The availability of multiple dosage forms for small molecules allows these medicines to be formulated to meet the diverse needs of different patient populations. These features, in turn, reduce barriers for patients to access and adhere to prescribed treatments, keeping patients healthy and reducing the need for use of other costly forms of medical care.
4. Small molecule medicines provide significant convenience for patients which can reduce health disparities.
Housing instability, unemployment and inadequate social support are just some of the factors associated with poor adherence to medicines. For example, evidence suggests that patients are 1.8 times more likely to be non-adherent if faced with transportation challenges. These factors have a disproportionate impact on disadvantaged communities who are the least positioned to handle them. But the relative convenience offered by small molecule medicines — which require fewer visits to a doctor or infusion center — can help reduce the burden of transportation limitations, caregiver costs, lost wages and other hurdles that have played a role in driving longstanding health inequities. These features in turn reduce barriers to patients taking medicines as prescribed and facilitate more equitable access to treatment and opportunities to reduce health disparities.
Given the numerous benefits of small molecule medicines, it's important that policies and regulations support and encourage their development so patients can continue to realize the benefits they provide, now and into the future.