Teaching the immune system what to fight - and what to spare

Two health announcements emerged 48 hours apart last week, seemingly unrelated. On Monday, the Emirates Drug Establishment approved a daily pill for vitiligo, a skin condition causing color loss in patches. Prior to this, no oral treatment was authorized for vitiligo patients, marking a first for the UAE. On Wednesday, Merck and Moderna announced their experimental cancer vaccine succeeded in a large late-stage trial for melanoma, another first.

Both stories share a common thread: the immune system. In one case, the immune system attacks the wrong target; in the other, it fails to attack the right one. The UAE is the first globally to approve a new oral vitiligo drug. Vitiligo occurs when the body destroys pigment-producing cells. Current treatments focus on surface-level management, such as creams, light therapy, or cosmetics.

The UAE-approved pill targets the signaling that drives the immune attack, a significant development for a condition affecting one in a hundred people and lacking a cure. Mirroring cancer, tumor cells are the patient's own cells gone awry, which explains why the immune system often overlooks them, carrying the correct identification.

Merck and Moderna devised a unique approach by providing the immune system with a photograph of these cells. The trial involving over 1,100 patients, whose skin cancer had been removed but was likely to recur, revealed that the vaccine combined with an existing cancer drug delayed recurrence and reduced the risk of cancer spreading.

The vaccine is uniquely tailored for each patient, with the batch size being one. While caution is advised due to limited full results, there is no new safety concern so far. It is crucial to note that this trial involved one type of cancer, with similar trials underway for lung, bladder, and kidney cancers. However, these trials are not yet complete.

The more intriguing question is whether this concept can be reversed. If the immune system can be taught to recognize something it has previously attacked, can it be taught to ignore something it has been attacking? Researchers are exploring this possibility, known as inverse vaccines. The aim is to induce tolerance to a specific target instead of dampening the entire immune system.

Early versions have demonstrated success in calming a multiple-sclerosis-like condition in animals, with ongoing research into celiac disease, type 1 diabetes, and rheumatoid arthritis. Current autoimmune drugs suppress the immune system, providing temporary relief but also weakening its vigilance, ultimately causing side effects.

Understanding the exact cause of specific autoimmune diseases will pave the way for targeted remedies. Although these developments may not reach patients immediately, the announcements signify a pivotal shift in medicine. While a century of progress has been made in accurately diagnosing diseases, the focus now shifts to training the patient's immune system to combat them effectively.

Frederik Cyrus Roeder, a health economist and writer based in Dubai, sheds light on this transformative journey.