What are potential new future treatments?

Topic: What will happen in the future?
Author: Robertson, Gary
Predicting the future is particularly hazardous in science because one unforeseen discovery can rapidly change all prospects for better or worse. Moreover, progress in this area will depend heavily on the availability of research funding and the willingness of patients to participate in research studies even though they cannot be guaranteed of any personal benefit. Based on what we already know, however, there are several exciting possibilities for improving the treatment or possibly even curing some inherited forms of nephrogenic diabetes insipidus.

One improved treatment that could be used even now in some patients is the administration of modified forms of the natural antidiuretic hormone, vasopressin. This approach is already known to completely control NDI in patients with vasopressin-receptor-2 mutations that cause incomplete resistance to the antidiuretic effect of the hormone and there exists several other analogs that have not even been tried as yet. The only obstacle to the immediate clinical use of one of these analogs is its expense and/or the need to develop a simpler and more convenient delivery system.

A second approach that may be relatively close to clinical application is the administration of smaller analogs of vasopressin that can get to and "rescue" certain mutant receptors that are trapped in the wrong part of the cell. This approach may well be effective in some of the patients who are not helped by the larger vasopressin analogs mentioned above. Nevertheless, it probably will not be effective in all patients because some have mutations that damage the receptor (or other crucial proteins) so severely that the hormone or its analogs will not work properly even if the receptor can be "rescued".

A third approach, which in theory at least could "cure" all patients with inherited NDI is so-called "gene therapy". The idea behind this approach is simply to give the patient another gene to make up for or correct the deficiency caused by the mutant gene. This strategy may be easier to effect in NDI than in some other inherited disorders because the cells where the new gene needs to go (in the collecting tubules of the kidney) are more readily accessible from the outside. Nevertheless, the other technical obstacles to this approach are still substantial and may not be overcome for some time. Therefore, it is difficult to predict when or even if this treatment will become a reality.