Comment by stalfie

Expensive and exotic vectors that target a particular tissue are potentially extremely valuable in the future. Gene therapy is now a thing, with new phase 2 trials showing incredible results coming out almost weekly (usually with a number needed to treat approaching 1, which is amazing).

The main issue is delivering the genetic patch to the tissue you want to fix. Some genes (eg. BRCA) are just really big and can't fit on some vectors, some tissues (eg. brain) are hard to reach, and you want to try to target tissues selectively, since we're not sure yet about side effects like insertional mutagenesis (although it doesn't seem to be a huge problem atm...probably depends on on the vector). A good vector makes a huge difference. Lipid nanoparticles for instance accumulate in the liver and can deliver all kinds of stuff, hence why there are so many studies targeting genetic errors of liver metabolism.

Exotic vectors for normal drugs are usually useless, as it would be too expensive for stuff needing daily or even monthly dosing (as long as it doesn't have a property of selectively targeting cancer). But for single dosage therapies, which gene therapies are, they are a potentially essential tool in the toolbox.

Edit: after writing this comment I just happened to check NEJM, and boom, yet another lipid nanoparticle based gene therapy in phase 3 which tremendous results: https://www.nejm.org/doi/full/10.1056/NEJMoa2600931?query=fe...

Linked this to illustrate the point. This is also a good example because the targeted genetic "patch" doesn't actually fix the underlying problem directly (C1 inhibitor deficiency), but goes about fixing the problem in a roundabout way just because that particular way involves the liver, instead of having to deliver the patch to all affected tissues (which in this disease is pretty much all of them). The treatment is thus just hugely effective instead of a complete cure. I personally have dealt with difficult cases of this particular disease in the past, and this treatment is a huge deal.