This article by Ng Wan Ching appeared in the Mind Your Body special of The Strait’s Times this week.
Six branded drugs will lose their patents in the next two years, paving the way for cheaper generic versions to come on the market and allowing patients to save on medication bills
Some big-name drugs are about to go generic, a shift that could save patients here millions in medication costs every year.
In the next one to two years, six of the 10 top-selling branded drugs in the world will lose their patents. Other companies will then be able to make the drugs and sell them at a huge discount.
In all, US$73 billion (S$90.5 billion) annually in patented drugs are expected to lose patent protection by 2015, said Ms Nadina Rosier, North American pharmacy practice leader at human resource, risk and financial consultancy Towers Watson in the United States, earlier this year.
The biggest drug blockbuster that will fall off the patent cliff is Lipitor, the cholesterol-lowering medication that has long been the top-selling drug in the world, generating US$7 billion a year in sales in the US alone. It will lose its patent in November.
Other patented drugs that are about to take a hit include the anti-psychosis drug Zyprexa (its patent expires next month), the blood thinner Plavix (next May) and the rheumatoid arthritis and psoriasis drug Enbrel (in October next year).
Psychosis is a group of mental disorders that causes patients to lose touch with reality, It includes schizophrenia. Rheumatoid arthritis results from the immune system attacking the joints, while psoriasis is a skin disease which causes itchy red patches or flaky scales.
Seroquel, used for treating severe mental disorders such as schizophrenia and depression, and Singulair, used to prevent asthma attacks, are also set to lose their patents next year.
Dr Ding Zee Pin, senior consultant at the department of cardiology at the National Heart Centre Singapore (NHCS), said: “When a branded drug’s patent expires, it opens the market to competition from cheaper generic forms of the same drug. This gives rise to substantial cost savings for patients.”
He cited Plavix, used to prevent blood clots after a recent heart attack or stroke, as an example. It is due to lose its patent in the US next year, but in Singapore, it went off-patent in 2008.
At Guardian Pharmacy, a tablet of Plavix now costs $4, while one of its generic versions costs about $2.70. Other generic versions may be cheaper and heart patients can save up to 70 per cent in costs.
Dr Ding expects Lipitor to go off-patent in Singapore later this year.
He said: “The generic version will bring about 40 per cent cost savings for heart patients.”
A price guide on the Pharmaceutical Society of Singapore’s (PSS) website shows that the price of one Lipitor tablet, depending on its dosage, can range from $2.60 to $8.45.
Heart patients may have enjoyed the savings that accrued when older statins went generic over the years.
Dr Ding said, for instance, the generic version of Simvastatin, one of the world’s most widely used cholesterol-lowering drugs, is 80 per cent cheaper than the patented drug, Zocor, whose patent expired some five years ago.
Under the PSS price guide, one 10mg tablet of Simvastatin costs between 46 and 79 cents. A Zocor 10mg tablet costs between 46 cents and $2.09.
Dr Ding said: “We estimate about 15 to 20 per cent of heart patients in Singapore are using one of the cardiovascular drugs whose patents will expire this year or the next year.”
A Ministry of Health spokesman told Mind Your Body that about 80 per cent of the drugsused in public hospitals and polyclinics here are generic ones.
“As more generic competitors enter the market, prices will come down and through our bulk purchase tender process, more patients will benefit from the lower cost of drugs,” said the spokesman.
Generic drugs are identical or within an acceptable bioequivalent range to their brand-name counterparts in dose, strength, route of administration, safety, efficacy and intended use, Dr Ding said.
Such drugs are manufactured under the same strict standards of the US Food and Drug Administration’s (FDA) good manufacturing practice regulations required for patenteddrugs.
The FDA said generic drugs have the same “high quality, strength, purity and stability as brand-name drugs”.
This is echoed by the Health Sciences Authority (HSA) here: “A generic drug is required to contain the same active ingredient, to have the same strength, dosage form and route of administration as the innovator product (the patented drug).”
Companies seeking approval of a generic product would usually need to show a bioequivalence study has been conducted in patients, demonstrating that the effect of the active ingredient in the generic product is similar to that of the patented drug.
Mr Ng Cheng Tiang, the honorary general treasurer of the PSS, said that as long as there is biological equivalence within plus or minus 20 per cent, it is believed that the generic drug will result in the same efficacy and safety as the patented drug.
It takes about 90 to 240 working days for a generic drug to be approved.
Once a drug is approved by HSA, the drug company will be allowed to sell and market it to health-care professionals.
As part of its active post-market surveillance programme, the HSA conducts regular product sampling of marketed health products to ensure that they meet the required standards for safety, efficacy and quality.
The reality, however, is that while generics are required to meet the same standards for quality and manufacturing as the patented drug, they may not always do so for many reasons.
Just as contamination can happen to patented drugs, it can also happen to generic drugs.
In 2008, Baxter Healthcare recalled its version of Heparin, a generic blood thinner, after it was found to be contaminated.
Eighty-one people in the US and Germany died after taking the tainted medication, although it is unclear how many deaths were related to the drug.
Studies have found that some generics do not act in exactly the same way as the patenteddrugs, which can be a problem for drugs that operate on a thin margin for error.
Researchers at Johns Hopkins University reported in the online version of Annals Of Neurology that some generic anti-epilepsy drugs are different enough from branded formulations that they may not be effective, particularly if patients switch between two generic drugs.
It raises questions about whether some generic products are safe or effective when a narrow dose range separates patients from help and harm.
Study leader Gregory Krauss, professor of neurology at the Johns Hopkins University School of Medicine, said epilepsy patients whose conditions are well-controlled on brand-name drugs often worry that switching to generic versions might mess with the medication levels in their blood, leading to seizures and side effects.
In an interview with Neurology Today, he said: “The question is: Are there sub-groups of patients that might have problems with a switch?”
The same question could apply to other pharmaceuticals in which over- or under-dosing by narrow margins may pose a problem, such as chemotherapeutics for cancer.
In these instances, patients might end up paying dearly with adverse effects or sub-optimum treatment when using a cheaper alternative.
Mr Ng said most patients on patented drugs can safely use generic versions if those are available.
But an important exception is when a patient is on a medication with a narrow therapeutic or safety index that requires close monitoring and doses to be exactly measured.
Some examples, he cited, are anti-rejection drugs, used after transplants, and anti-coagulants, to thin the blood.
Patients using such drugs are usually kept on the same brand, he said, and do not risk a switch.