As part of Breast Cancer Awareness Month, we look back at several innovations developed to combat breast cancer: targeted therapies, artificial intelligence and experimental vaccines.
These innovations are the result of years of research and development and raise intellectual property issues. What are these innovations, and how can they be protected by patents?
Enhertu®: From the medicinal product to patient selection
Trastuzumab deruxtecan, marketed under the name Enhertu®, belongs to the family of antibody-drug conjugates (ADCs). These medicinal products combine an antibody that recognises a cellular target with a cytotoxic molecule capable of destroying cells. A chemical linking element, known as a linker, connects the two components.
In Enhertu®, the antibody targets HER2, a receptor located on the surface of cells and involved in growth signalling. This recognition enables the cytotoxic molecule to be delivered to cells expressing HER2.
Developed by Daiichi Sankyo in collaboration with AstraZeneca, Enhertu® has gradually seen its therapeutic indications expand. On 31 March 2025, its marketing authorisation in Europe was notably extended, as monotherapy, to certain unresectable or metastatic hormone receptor-positive breast cancers with low or very low HER2 expression, following at least one endocrine therapy in the metastatic setting. More recently, on 8 October 2026, the French National Authority for Health (HAS) granted early access to Enhertu® for another indication, following surgery, in certain patients with HER2-positive breast cancer with residual invasive disease after preoperative HER2-targeted treatment.
The molecular architecture of this ADC is itself protected by a patent. European patent EP3101032B1, filed by Daiichi Sankyo and granted, claims anti-HER2 conjugates defined in particular by their cytotoxic payload, the structure of the linker and their attachment to the antibody. The protection sought here therefore concerns the medicinal product as such.
The development of a medicinal product may also lead to the identification of patients likely to benefit from it. This selection may form part of the definition of a therapeutic use eligible for patent protection.
European patent EP4211598B1, filed by Daiichi Sankyo and AstraZeneca, provides an example. It claims an anti-HER2 ADC for treating patients whose score, calculated from images of tumour tissue, exceeds a threshold. The calculation takes into account, in particular, the intensity of HER2 staining in cancer cells and neighbouring cancer cells. One claim expressly relates to trastuzumab deruxtecan.
It is therefore possible to protect by patent a medicinal product itself, its preparation process and new therapeutic uses, particularly in patients selected according to defined criteria.
Artificial Intelligence (AI) in support of screening
Artificial intelligence (AI) is also being studied to improve the analysis of medical images and facilitate the early detection of cancers.
In January 2026, the results of the Swedish MASAI study, conducted among more than 100,000 women, notably confirmed the value of AI as a tool to assist in mammogram interpretation.
The rate of interval cancers, diagnosed between two screening examinations, was approximately 12% lower in the AI-assisted group, although this difference was not statistically significant. The study established the non-inferiority of this approach compared with standard double reading for this endpoint.
International patent application WO2022184701A1, filed by ScreenPoint Medical, focuses on the risk of breast cancer being detected within a given interval following a negative screening result.
The claimed device uses an AI model trained to combine two parameters derived from breast images: an indicator of the probability that cancer is present and an indicator relating to breast density. The description envisages using this estimate to adjust the interval between screening examinations or suggest an additional examination.
In Europe, computer-implemented inventions may benefit from patent protection provided they meet the patentability requirements, particularly novelty and inventive step.
In the medical field, image-processing methods or algorithms for identifying abnormalities may therefore be eligible for patent protection. When assessing inventive step, the European Patent Office (EPO) takes algorithmic features into account insofar as they contribute to the technical character of the invention considered as a whole. The claimed solution must also be non-obvious in view of the prior art.
Cancer vaccines: A new avenue of research
Another avenue of research concerns vaccines designed to mobilise the immune system against certain cancer cells.
The experimental vaccine being studied by the Cleveland Clinic, in partnership with Anixa Biosciences, targets alpha-lactalbumin, a protein expressed in certain breast cancers. This protein acts as an antigen: it constitutes the target against which the vaccine seeks to trigger an immune response.
The Phase I trial, conducted among 35 participants, showed an immune response in 74% of them and enabled the maximum tolerated dose to be determined.
However, these results remain preliminary: the ability of this vaccine to prevent the development or recurrence of breast cancer has not yet been demonstrated and will need to be evaluated in subsequent clinical trials.
US patent US12370244B2 relates to this immunisation approach. It claims a method comprising the administration of a composition containing human alpha-lactalbumin defined by its sequence.
The role of patents in the development of medical innovations
Whether they involve new medicinal products, experimental vaccines or AI-assisted image analysis tools, medical innovations often require several years of development and substantial investment.
In this context, patents make it possible to protect and create value from inventions arising from research. They can facilitate collaboration between public research institutions and industrial partners, support technology transfer and encourage the fundraising often required to develop these innovations.
However, patent protection is no substitute for the scientific validation or the clinical and regulatory assessments that are essential before a medical innovation can be made available.
During breast cancer awareness month, it is also important to reiterate the importance of breast cancer screening.
In France, women aged 50 to 74, with no symptoms or particular risk factors, are invited to undergo a mammogram and a clinical examination every two years as part of the national organised screening programme. These examinations are fully covered by the French national health insurance system.
Because cancer detected early generally offers better prospects for care, let us not forget the importance of screening.
November 2026
Contributing author
Nawhel
Guillaumey
Patent Attorney
