Gene therapy has become a hot spot in the field of drug research and development. This article will introduce the classification, global market, approved drugs, and future prospects of gene therapies.
Gene Therapy Classification
According to the classified definition of FDA, gene therapy is a technique that treats diseases by changing a patient’s genes. The mechanisms of gene therapy are as follows.
- Replacing: replaces the pathogenic gene with a copy of the healthy gene.
- Inactivating: inactivates abnormal pathogenic genes.
- Introducing: introduces new or modified genes into the body to help treat diseases.
The current treatment areas of gene therapy products include tumors, genetic diseases, infectious diseases and so on.
FDA divides gene therapy products into five categories according to the technical approach.
- Plasmid DNA: is a genetically engineered circular DNA molecule capable of introducing therapeutic genes into human cells.
- Viral vectors: viruses have the natural ability to introduce genetic materials into cells, so some gene therapy products come from viruses. Once the virus has been modified to remove its ability to cause infectious diseases, the modified virus can be used as a vector vectors (vehicles) to introduce therapeutic genes into human cells.
- Bacterial vectors: bacteria can also transfer therapeutic genes into human tissues by modifying their ability to remove their ability to cause infectious diseases.
- Human gene editing technology: the goal of gene editing is to destroy harmful genes or repair mutated genes disrupt harmful genes or to repair mutated genes.
- Cell-based gene therapy products: after the cells are extracted from the patient, they are genetically modified (usually using viral vectors) and then returned to the patient.
In addition, gene therapy products can be divided into two categories according to in vivo and ex vivo. As shown in left side of the picture above, in ex vivo gene therapy, the cells are transferred back to the patient after ex vivo modification; the right side shows in vivo gene therapy, where cell gene modification takes place in vivo, and AAV and liposome nanoparticles belong to in vivo gene therapy.
Gene Therapy Market
According to EvaluatePharma and BCG analysis, the global gene therapy market in 2018, 2021 and 2024 is US $18 million, US $2.886 billion and US $14.021 billion respectively.
According to Deloitte, the global cell and gene therapy market CGT will reach $11.96 billion by 2025.
Compared with other treatment techniques, such as monoclonal antibody, vaccine, DNA/RNA therapy, etc., the market size and growth rate are as follows. According to EvaluatePharma and BCG, the global market for macromolecular and biotech treatments in 2024 is US $430 billion.
| Therapies | Accounting | Market size in USA | CAGR in 2018-2024 |
| Monoclonal antibodies | 45% | $193.5 billion | 8% |
| Recombinant products | 24% | $103.2 billion | 1% |
| protein extracts | 9% | $38.7 billion | 7% |
| Bioengineering vaccine | 9% | US $38.7 billion | 9% |
| Cell therapy | 4% | $17.2 billion | 70% |
| Gene therapy | 3% | $12.9 billion | 150% |
| Monoclonal antibody conjugates | 3% | $12.9 billion | 35% |
| DNA/RNA treatment | 2% | $8.6 billion, | 35% |
| Others | 1% | – | – |
From the perspective of the global pipeline layout, according to the number of pipelines and R&D / approved ratio in different areas of EvaluatePharma and BCG, by the end of 2019, the R&D / approved ratio can see the relative maturity of technology, the popularity of the industry and so on.
| Therapies | Number of pipelines | Number of R&D / approved |
| Monoclonal antibodies | 6299 | 6.3 |
| Recombinant products | 3027 | 1.3 |
| Bioengineering vaccine | 2779 | 3.7 |
| Cell therapy | 2374 | 15 |
| Protein extracts | 1759 | 0.5 |
| Gene therapy | 990 | 67 |
| DNA/RNA treatment | 963 | 26 |
In the gene therapy category of EvaluatePharma and BCG, the overall market in 2024 is US $14.021 billion, and the disease area is classified from large to small as follows.
- Blood diseases, $3.521 billion.
- Skeletal muscle diseases, $3.362 billion.
- Central nervous system diseases, $2.183 billion.
- Eye diseases, $1.267 billion.
- Skin diseases, $833 million.
- Tumors, $400 million.
- Cardiovascular diseases, $240 million.
- Digestive system diseases, $144 million.
- Immune diseases, $115 million.
- Others, $1.956 billion.
For rare diseases caused by single gene mutation, gene therapy can achieve a permanent cure, which is the mainstream of the current research, such as spinal muscular atrophy, hemophilia, Leber congenital amaurosis and so on.
For diseases with multiple gene mutations, such as spina bifida and essential hypertension, the current technology for simultaneous targeting of multiple genes remains to be broken through.
Approved Products for Gene Therapy
In addition to 8 hematopoietic progenitor cell (HPC)-based therapies, FDA has approved the following 10 cell and gene therapy products (according to the time of approval).
- PROVENGE (sipuleucel-T), an autologous cell therapy technique for treatment of castration-resistant prostate cancer with asymptomatic or mild symptomatic metastasis, and was approved in 2010 as a gene therapy product.
- LAVIV (Azficel-T), whose indication is to improve moderate and severe nasolabial furrow wrinkles in adults, was approved in 2011 and belongs to gene therapy products.
- GINTUIT, the first cell-based product made of allogeneic human cells and bovine collagen for the treatment of vascular injury caused by adult membrane gingival surgery, was approved in 2012 as a cell therapy product.
- IMLYGIC (talimogene laherparepvec), the world’s first oncolytic virus approved product for treatment of unresectable skin, subcutaneous and lymph node lesions of patients with recurrent melanoma after surgery, was approved in 2015 and belongs to gene therapy products.
- MACI, developed to autologous culture chondrocytes for porcine collagen membrane for symptomatic full-thickness defect of knee in adult patients, was approved in 2016 and belongs to gene therapy products.
- LUXTURNA (voretigene neparvovec-rzyl), a gene therapy for retinal dystrophy caused by RPE65 gene defect, was approved in 2017 and belongs to gene therapy products.
- KYMRIAH (tisagenlecleucel), a CAR-T treatment product with indications for refractory or recurrent acute B-line lymphoblastic leukemia, was approved in 2017 and belongs to gene therapy products.
- YESCARTA (axicabtagene ciloleucel), another CAR-T therapy product for relapsed / refractory large B-cell lymphoma, approved in 2017 and belongs to gene therapy products.
- ZOLGENSMA (onasemnogene abeparvovec-xioi), for the treatment of a spinal muscular atrophy caused by a mutation in the SMN1 gene under 2 years old, was approved in 2019 and is a gene therapy product.
- TECARTUS (brexucabtagene autoleucel), for the treatment of recurrent / refractory mantle cell lymphoma, was approved in 2020 and belongs to gene therapy products.