The implementation of diagnostic, therapeutic, and monitoring
strategies precisely tailored for each individual patient is increasingly
common, perhaps most notably in oncology. Such
“precision medicine,” ultimately guided by a molecular taxonomy
of disease, as well as detailed molecular knowledge of disease
course and therapeutic response, has been articulated as a vital goal
for the future of medicine.1 The unprecedented pace of scientific
progress and technologies for the deep molecular interrogation of
biological samples has arguably outpaced the ability to translate
this data into useful patient interventions. Nevertheless, there are
emerging areas in which such data has been successfully used to
create, implement, and monitor therapies.
In this issue, we explore the state-of-the-art in precision
medicine across a wide spectrum of dermatologic disease, including
nonmelanoma skin cancers, Merkel cell carcinoma,
melanoma, psoriasis, inherited structural diseases, and the skin
microbiome.
The existence of dominant driver pathways in both melanoma
and basal cell carcinoma has resulted in the rapid development of
specific inhibitors of ERK2,3 and Hedgehog signaling,4,5, respectively
with substantial clinical benefit. Despite the fact that such
targets have not been identified for squamous cell carcinoma or
Merkel cell carcinoma, intense research efforts are now aimed
at identifying appropriate targets. Immunotherapies that induce
checkpoint blockade against PD1 or CTLA4 signaling have shown
great promise, particularly in melanoma.6,7 It is possible that this
type of immunomodulation will eventually have a role in the treatment
of squamous cell carcinoma and Merkel cell carcinoma.
The identification of specific genetic defects in inherited disorders
of basement membrane presents a different problem. Many
targets are known, but the delivery of gene replacement has proven
to be difficult. It is unclear which technologies are most likely to
be effective and result in stable expression of components in the
appropriate cell types and contexts.
Molecularly targeted therapies are not limited to cancer. The
advent of biologicals for the treatment of psoriasis has not only
validated the targeting of numerous cytokines and their cognate
receptors, but has resulted in dramatic and sustained responses.8
However, the complexity of evaluating clinical response, predicting
response and managing adverse effects presents numerous
challenges in the optimal assessment and management of moderate
to severe psoriasis.
Finally, the microbiome has emerged as an exciting new frontier
of skin biology.9 The finding that bacterial diversity and composition
on skin differ by location and in disease states, suggests critical
roles for heretofore unappreciated skin-immune interactions
and novel therapeutic approaches for inflammatory disorders.
These articles are authored by leaders at the forefront of their respective
fields of expertise. The diversity of dermatologic disease
and the effective translation of deep biological understanding to
enable effective therapy pose significant challenges; however, the
enormous progress that has been made bodes well for continued
future success.