Four Steps to Filing an Opposition

There are four main steps to building your opposition. Each step requires research, since you will be dealing with complex issues. We’ve included links to the resources you’ll need as we go along.

Step 1: Fundamentals

Before you begin, it’s important to check two key issues:

  • Is there no generic competition because the drug is protected by patents?

  • Who is allowed to contest patents, when, and by what means?

These questions are fundamental. If you discover that patents are not the reason that your drug of interest is not available in generic variants, then you will need to pursue a different path.

And if you learn that patent oppositions are only allowed from researchers or commercial entities, or can only be submitted within a specific timeframe, you may have to adjust your plans.

Absence of generic competition

You know that there are no generic versions of your drug in the country you’re working in — that’s why you’re considering a patent opposition in the first place.

But that might not always be because it’s protected by patents.

Check the legislation in your country

You’ve identified that patents are the reason why there are no generic versions of the drug in your country.

Now you’ll need to check the legislation in your country of interest to find answers to the following questions, and consult our suggested resources, ask other people who use this site for help, and, if all else fails, conduct your own research.

1. The system: Is there a framework for patent examination in your country of interest?
2. The timing: Is it permissible to present a pre-grant opposition, a post-grant opposition, or both?

Note that a country’s patent legislation may not necessarily use the specific terms ‘pre- or post-grant patent opposition’. It may use terms such as ‘representation’ or ‘observation’ for both pre- and post-grant oppositions.

3. The letter of the law: How does the country interpret patentability requirements?

Countries who are members of the World Trade Organisation (WTO) adhere to the general international patent rules that are in the WTO’s TRIPS Agreement.

However, TRIPS leaves the scope of interpretation of these terms open to each WTO member country. As a result, WTO members have taken different approaches, choosing definitions that best suit their needs. The flexibility to interpret also applies to the detailed criteria on the three general requirements - so-called ‘patentability’ - to patent protection: novelty, inventiveness and industrial applicability.

Crucially, to contest a patent, you will have to prove that it fails to meet the patentability standards that are set out in the country or region’s own patent laws.

Validity may also be affected by other agreements that countries have signed, such as free trade agreements.

Unfortunately, it is not always a simple matter to gain full understanding of a country’s patent standards.

Just looking at the law may not be enough to determine how a country interprets patentability requirements. You may also need to check relevant patent regulations, patent examination guidelines issued by patent offices, and any court cases that can provide critical information on how these provisions are interpreted.

Note: Keep an open mind as you do this research, and do not be dissuaded. Even when a country has strict standards for patentability, there is no guarantee that they have been adequately applied.

It’s also important to be aware that pharmaceutical corporations invest in clever designs for their patent applications to claim novelty or inventiveness where they may not exist as a way of dealing with legal requirements.

4. The litigant: Who is entitled to file an opposition?

Some countries have legislation that restricts who can file an opposition to industry or those involved in scientific research, such as universities and public institutions. Other countries recognize the rights of any person, including patient groups, to file an opposition by following some procedures of the local laws. The right to challenge a patent by anyone at any time is extremely important, and should be added as a key amendment in patent laws that do not include it. For example, a patent blocking access to affordable medicines can injure people affected by a specific disease, so the definition of who can be considered as third parties interested in the granting of a patent must be as inclusive as possible.

5. Time limits: What is the period for filing an opposition?

In some countries, pre-grant oppositions must be filed within certain strict time limits. Make sure you are aware of them — they can be crucial.

6. Procedural requirements: What rules must be adhered to in submitting an opposition?

Should your opposition be submitted in writing - and if so does it need to be a hard copy on paper, or is email acceptable? What notifications are necessary, within what timeframes? Are you required to work with a local lawyer or agent to submit the opposition?

7. If all else fails: Does the system need fixing?

Some countries have procedural aspects that can make patent oppositions restrictive, or costly.

In some cases, the answer to these questions may point to the need to improve the local examination system, or to put one in place. For example, If the period for filing an opposition is very short, if the patent office isn’t required to take the opposition into account, or if civil society is excluded from filing an opposition, then it may be necessary to improve the legislative framework, which includes the patent law and all other patent-related regulations.

These restrictions and limitations could be addressed by advocating and campaigning for changes in national patent laws, such as the current campaign led by the Treatment Action Campaign and other civil society organisations to amend South Africa’s patent laws. For more information on the campaign, visit

Step 2: locate the patent(s)

Before considering a patent opposition to stimulate generic competition, it is important to check two key issues: is the absence of generic competition a consequence of patent protection; and, if so, which patent(s) cover this medicine and are blocking generic competition.

Undertaking a patent search

After you’ve determined that access to your drug is restricted by patents, not the factors listed above, and discovered that the path is clear for you to file an opposition, the next step is to find out if patent applications have been filed in your country of interest. This is done by undertaking a search at your local patent examination office, where you can check to see whether patents are pending (the patent office has not yet made a decision on the patent application), or have already been granted or rejected.

First, you will need some understanding of how and where patents are filed, and how to read a patent application.

One medicine, many patents

Many people assume that a patented medicine is protected by one particular patent. Unfortunately, it is not that straightforward.

Patents do not protect medicines, but ‘inventions’. In the pharmaceutical sector, to postpone the date that their products will go off-patent, companies file numerous applications around their invention.

So, suppose that the medicine’s formulation includes a specific molecule, the ‘invention’ that is central to the patent. In addition to a patent on the molecule itself, patents can also cover ‘process’ (the means by which the molecule is manufactured), ‘formulation’ (the form the medicine takes, e.g. powders, tablets and capsules, etc.), dosage (route, regimen), combinations (e.g. a fixed-dose combination when different drugs are combined in the same pill), new use (i.e. an existing medicine for which a new use has been found), and derivatives (salts, prodrugs, crystals, polymorphs).

Not all of these patents may prevent generic competition. Some patents can be easily worked around to launch generic products without infringement: imagine, for example, a new way to manufacture the same molecule.

So it’s important to locate each patent that covers your medicine: you can analyse them later, to check whether any of them actually do block generic competition.

Dealing with a lack of transparency

Patent information should be transparent, but it often isn’t.

Sometimes it isn’t obvious that the patent application refers to the medicine you’re researching.

A company only has to describe the subject matter of the invention (e.g. the chemical formula of a molecule), and they seldom use the chemical or international non-proprietary name (INN) or the brand name of the medicine.

In any case, a patent on a new compound is filed before the medicine is formally registered and has a proper INN assigned to it. So don’t give up if a search if the medicine’s name doesn’t yield results. Instead, look for the chemical formula or other invention that the patent is likely to refer to.

Be prepared for setbacks

Pharmaceutical corporations are not willing to disclose all of the patent applications related to a medicine, often keeping this information confidential.

Access to commercial databases and information services that provide overviews of patent applications and the patents that are related to specific medicines can be expensive.

Patent offices in developing countries generally have information on which patent applications are pending or which patents are still in effect, although it may not always be up-to-date or accurate. Information and source documents are often not made public - or even disclosed on request. Requests for patent searches in patent offices are not always free and can be expensive in some countries; in developing countries, some patent offices lack the capacity to respond to requests for information.

All of this can make your task more difficult, so be prepared for setbacks.

Here in the Patent Opposition Database, the search engine on the homepage was designed to overcome some of these barriers. By typing the name of a drug, you may find corresponding patent information already uploaded by other users, or links to other sources where patent information on medicines is collected.

Anyway, looking at your country databases is essential, to ensure you have an accurate picture of the patent situation.

1. Use the ‘patent landscape’.

Explore previous searches and studies that others have made on medicines.

Try the resources listed above. You can also use the drug pages of this database to see if there are materials relating to your medicine. Previous oppositions on the same drug can also provide information on relevant patents: find them on each drug page by clicking on ‘patent oppositions’.

2. Learn how to conduct a patent search.

If there is no patent landscape for a medicine, it is worth exploring the possibility of conducting a patent search. We recommend that you read the World Health Organisation’s Guide to Patent Searches [PDF] before continuing.

Even if there are patent landscapes available, a patent search will often yield valuable local information, and is worth the effort. Most guides will refer to the US Food and Drug Administration (FDA) and Health Canada online patent registries as a starting point, since many key patents are listed on these sites (with their INNs).

The information you get from these sites can be used at your local patent office, to ask for the corresponding applications in your country.

The World Intellectual Property Organization (WIPO) also has a searchable online database for patent applications that can provide information on where patents applications may have been submitted; this may help you to find the corresponding patent applications that are pending or have been granted in your own country.

3. Share your findings.

As you can see, the Patents Opposition Database works best when users share their resources — so if you discover useful patent information, or a patent landscape that is not yet included here, please submit it for inclusion.

Step 3: Searching and analysing

If you’ve completed Steps 1 and 2 (Fundamentals and Locating the Patent), you now have a good overview of what’s legally possible in your country of interest. You’ve located the relevant patents, and found materials that may help you to contest them. Now it’s time to build your opposition.

This is the stage when you will almost certainly need help from someone with a legal or pharmaceutical background. As you’ll see, this site can help you find them.

Building arguments for an opposition

You’ll be trying to prove one or more of the following:

  • That the patent application does not fulfil one or more of the requirements (novelty, inventiveness and industrial applicability);
  • That the drug or medical product is non-patentable in other ways;
  • That the patent or application fails to meet other requirements set out in the laws of your country of interest (e.g. sufficient disclosure of the invention).

To do this, you’ll need to assess the claims in the patent application documents. This is a technical task: claims are complex, and understanding them often requires a legal and chemical background to properly judge the merits of the invention.

If you do not have access to such expertise, our ‘call for help’ feature can be useful. It allows you to ask other users of the site to share their expertise.

You can use the Patent Opposition Database search tool to find patent oppositions relating to specific drugs or types of patent applications. These can be used to identify similarities between the arguments used in different oppositions.

Adapting an existing opposition to your country

In step 2, you researched the patent landscape. If you found oppositions from other countries, you’re in luck. Understanding the claims that were contested - whether successfully or not - will help to inform your own argument.

Finding an existing opposition will save a lot of work, although you’ll still need to use the research you did in Step 1 (when you found out about laws governing patent oppositions in your country of interest). You may find that the grounds on which the claims were contested are not allowed by your country’s laws.

Even if you are not able make similar arguments, existing oppositions can be a great help. The rationale used in other countries can be a good starting point and reference when you come to formulate your own opposition.

Identify the description, claims and subject matter

To draft an opposition, you will need access to a) the description and b) claims in the patent application. The description opens by ‘setting the scene’ for the invention, while the claims define the scope of the patent protection that the applicant asked for.

Next, identify the subject matter of the patent protection: it could, for example, be a molecule or group of molecules; a salt; a process; a formulation; a combination; a dosage form — or something else.

Step 4: File your opposition

Once you have gathered all the information and formulated your arguments, you need to compile them into a written document that complies with the rules on patent opposition in your country of interest.

Then, opposition can be filed. Every country has its own filing procedures. Patent oppositions may be an administrative procedure, dealt with by the patent office, a judicial office, or dealt with by the court. Consult your country’s patent authority website to see exactly what they require.

At a minimum, most authorities will require the following information:

  • Name and legal information of the opponent(s);
  • Reference to the law allowing for opposition;
  • Reference to the legal standing of the opponent(s);
  • Summary of the arguments that justify the request for refusal;
  • Summary of the claims made by the applicant;
  • The grounds for the opposition (in detail);
  • Request for subsequent actions to be taken by the court or patent office such as revoking or refusing to grant the patent.