About Our Company

4DMT is a gene therapy company with a transformative discovery platform—Therapeutic Vector Evolution—that enables our “disease first” approach to product discovery and development, thereby allowing us to customize our AAV vectors to target specific tissue types associated with the underlying disease.

At 4DMT we are creating and developing targeted and evolved AAV vectors that will allow us uniquely to unlock the full potential of gene therapy. Our targeted and evolved AAV vectors are each designed, according to a 4DMT Target Vector Profile, to deliver genes to specific cells and tissues in the body to eradicate both rare and large market diseases.

While AAV gene therapy pioneers are making great strides with the first wave of products, hurdles still exist with the use of conventional vectors. The most commonly used AAV capsids (eg, AAV2, 5, 8 and 9) were identified either 1) as contaminants in lab stocks of adenovirus, or 2) through monkey tissue processing. Therefore, these conventional vectors are not targeted specifically to any tissue in the body. This can lead to inefficient and non-specific delivery, thus requiring extremely high doses and potentially resulting in toxicities (including inflammation), high manufacturing burdens and suboptimal efficacy. In addition, suboptimal routes of delivery can be required for delivery to the right tissues (eg, subretinal delivery to the retina). Finally, pre-existing neutralizing antibodies in many patients can limit efficacy, clinical trial enrollment and market sizes. 4DMT Innovation empowers us to create new and improved next generation AAV capsids to allow targeted delivery of our products by the optimal clinical route of administration.

At 4DMT we use our robust discovery platform, termed “Therapeutic Vector Evolution”, to create customized and proprietary gene delivery vehicles (novel AAV vectors) to deliver genes to specific tissues and cells in the body by the optimal route of administration. We use the power of evolution to create and refine these optimized vectors as follows:


We create highly complex and unique vector capsid “libraries” for high-throughput screening. To date we have created 37 AAV capsid libraries comprising more than an estimated one billion novel variants. We therefore have roughly 100 million times more vectors to choose from than are used in conventional AAV gene therapy products.


We use the power of natural selection to isolate the “most fit” vectors for any “Target Vector Profile” (TVP) we want. The TVP will define the cell types and intra-organ distribution to be targeted, the route of administration, the dosage required for delivery, and resistance to pre-existing antibodies in the population if desirable.

Once we have created and refined these highly optimized 4DMT AAV vectors, we then engineer them to carry a wide array of therapeutic transgene payloads for the treatment of diverse diseases, in addition to filing composition-of-matter patents and therapeutic use patents.

Our proven team of biotherapeutics developers and innovative gene therapy scientists have highly complementary skill sets. Prior to forming 4DMT, our CEO, David Kirn, MD, and development team members have developed over 10 different therapeutic viral vectors, including translation into the clinic and Phase 1-3 clinical development in over 30 clinical trials. Our Chief Scientific Advisor and co-founder, Dr. David Schaffer, Ph.D., pioneered the application of directed evolution to the capsid of AAV vectors over 15 years ago. Our scientists and other team members’ complimentary skill sets empower us on our quest to bring the best possible therapeutic products to patients who desperately need them.