Welcome back to the journal review. This is the January 2026 issue of the Journal of the American Academy of Dermatology, and we've got four pieces worth your time this month — a sustainability intervention study out of a Mohs clinic, pivotal long-term data on a new PD-L1 inhibitor for advanced cutaneous squamous cell carcinoma, a randomized trial on topical timolol for secondary-intention wounds with a bonus brief report on hidradenitis inpatient care, and a research letter on age as a prognostic factor in stage two melanoma. Let's get into it.

First up is an original intervention study out of West Virginia University looking at the carbon footprint of a Mohs surgery clinic — this is essentially an operations and sustainability paper, not a clinical outcomes paper, but it's directly actionable for anyone running a surgical suite. The background here is simple: healthcare generates something like one-tenth of US greenhouse gas emissions, and Mohs surgery, done well over 800,000 times a year in this country, hasn't had its downstream waste and electricity footprint carefully mapped. So the authors set out to quantify it and then actually intervene.

Methodologically, this is a before-and-after observational study, not a randomized trial — which makes complete sense here because you're measuring a single clinic's operational footprint, not comparing patients. They measured electricity use and waste output over a baseline week, then implemented a bundle of interventions and remeasured over a second week, feeding the numbers into a standardized carbon calculator, the Mazzetti M-one WasteCare tool, plus an EPA equivalency calculator to translate emissions into relatable terms. The interventions themselves were a mix of low-tech behavioral fixes — correctly sorting pathological versus regular trash, adding a conveniently placed trash bin next to the biohazard bin, starting a recycling stream, minimizing and right-sizing chucks — and some that were only modeled hypothetically, like switching to washable surgical towels and adding motion-sensor lighting, because those required longer administrative coordination than the study window allowed.

The results are honestly striking for how little effort was required. Total downstream emissions dropped about 15%, from roughly 320 tons of carbon dioxide equivalent a year down to about 272 tons. Waste dropped by a third. And electricity usage fell a remarkable 71%, driven almost entirely by fixing lighting habits — motion detectors and LED swaps accounted for the bulk of that. That translated into an annual cost saving of around twenty-seven hundred dollars just from the electrical side. Maybe the most clinically interesting number for practice management: before the intervention, waste — not electricity — accounted for 95% of the clinic's downstream emissions, and biohazard waste dropped from about a quarter of total waste down to under one-tenth after staff were simply retrained on what actually counts as biohazardous versus regular trash.

Limitations are modest and mostly methodological — this is a single academic clinic, a two-week measurement window, and the accuracy is bounded by whatever assumptions are baked into that WasteCare calculator. It's also worth noting several of the biggest theoretical gains, like the washable towels and full lighting retrofit, were modeled rather than actually implemented, so the real-world savings could differ.

Practical takeaway: this is genuinely low-effort, practice-changing stuff you could implement next week without any capital investment — retraining staff on biohazard versus regular trash sorting, adding a conveniently placed trash bin, and putting timers or motion sensors on lights. The towel-switching and full LED retrofit are more aspirational and require facilities coordination, but the paper gives you a clear cost-benefit argument to bring to your practice manager.

Second, an original study reporting long-term follow-up from the pivotal open-label trial of cosibelimab, a PD-L1 inhibitor, in advanced cutaneous squamous cell carcinoma. Background here: cemiplimab and pembrolizumab, both PD-1 inhibitors, are already standard of care for locally advanced or metastatic disease, but PD-1 blockade carries a meaningfully higher rate of severe immune-related adverse events compared to PD-L1 blockade in other tumor types. Cosibelimab is a fully human, high-affinity PD-L1 antibody that also engages antibody-dependent and complement-dependent cytotoxicity, and it already received FDA approval in December 2024 based on an earlier data cut from this same trial. What we're getting now is the mature, longer follow-up data, including previously unpublished results for the locally advanced cohort.

This is a nonrandomized, open-label, multicohort phase one trial — patients got cosibelimab either 800 milligrams every two weeks or 1200 milligrams every three weeks, with the two regimens considered pharmacokinetically equivalent per FDA guidance. The authors don't spend much time justifying the single-arm design, but it's worth noting explicitly: in this rare, orphan-drug-adjacent population with historically dismal outcomes and no acceptable standard first-line comparator once surgery and radiation are off the table, a single-arm registration trial is the conventional and ethically pragmatic path — this mirrors how cemiplimab was originally approved. Response was assessed both by independent central review using RECIST for radiologic lesions and WHO bidimensional criteria for cutaneous lesions assessed photographically, which is a sensible hybrid given that CSCC often presents with visible skin disease that doesn't fit neatly into standard radiologic response criteria.

At a median follow-up approaching two and a half years for the metastatic cohort and right around two years for the locally advanced cohort, the numbers held up and, notably, improved with time. Overall response rate in metastatic disease was 50%, with complete responses in about one in eight patients. In the locally advanced cohort, response rate was even higher at roughly 55%, with complete responses now up to about one in four patients — a meaningfully higher complete response rate than what was reported at the earlier data cut, which is the kind of trend you want to see with longer follow-up on a checkpoint inhibitor. Median duration of response wasn't reached in either cohort, and the estimated proportion still responding at two years was around 72% for metastatic and 80% for locally advanced disease — durable responses, in other words, not just early shrinkage that fades. On safety, immune-related adverse events occurred in about a quarter to a third of patients, but severe grade three events were uncommon at under 4%, and there were no grade four immune-related events at all.

Limitations are the ones you'd expect and the authors state plainly: no randomization, no control arm, and limited biomarker work, so we still don't have a great way to predict who responds. Generalizability to real-world, often older and more comorbid CSCC patients also deserves some caution given trial selection criteria.

Practically, this is meaningful confirmation rather than brand-new information — cosibelimab is already FDA approved, so the practice-changing decision has effectively already been made for you. What this paper adds is reassurance that the responses are durable and even deepening over time, and a genuinely differentiated safety signal — low rates of severe immune-related toxicity — that may make this an attractive option, particularly for patients where you're worried about steroid-refractory or high-grade immune toxicity from PD-1 blockade. Worth knowing as you counsel patients and coordinate with medical oncology, even though it doesn't change your surgical decision-making directly.

Third, a randomized controlled trial — a brief report — testing whether 0.25% topical timolol gel accelerates healing of post-Mohs wounds left to heal by secondary intention. The rationale traces back to older case reports and small series suggesting topical beta-blockers might promote wound healing, and the appeal here is obvious: timolol gel is commercially available, cheap, and already familiar to us from glaucoma management, so if it worked, it would be an easy addition to the secondary-intention toolkit.

This was a parallel-group randomized trial at Brigham and Women's, enrolling adults with post-Mohs wounds under 1.5 centimeters planned for secondary intention healing. Patients were randomized to timolol gel or Vaseline as standard of care, applied immediately after surgery and then daily at home, with standardized photographs at one, two, four, twelve, and twenty-four weeks. The primary endpoint, time to re-epithelialization, was adjudicated by two blinded physicians reviewing photos, with a third blinded physician as tiebreaker — a sensible approach given how subjective visually assessing "complete" re-epithelialization can be, and blinding the photo reviewers is the right way to minimize assessment bias in a trial where the intervention itself obviously can't be blinded to the patient or treating surgeon.

The result was unambiguous and negative: median time to re-epithelialization was 90 days in both groups, with completely overlapping Kaplan-Meier curves in both the intent-to-treat and per-protocol populations, and the result held even after adjusting for baseline imbalances in age, wound size, and comorbidities using Cox regression. Pain and satisfaction scores were roughly similar between groups, though standard-of-care patients reported slightly higher pain. Two patients discontinued timolol due to local irritation or systemic side effects like nausea and headache — a reminder that this isn't a completely inert intervention, even though it's over-the-counter-adjacent in concept.

The authors are appropriately modest in their conclusion — timolol did not accelerate healing in this trial, and they call for further investigation specifically in more chronic, non-healing, granulating wounds rather than routine post-Mohs defects. Limitations include the small sample size and the fact that this population's wounds were, by design, small and expected to heal reasonably well on their own, which may have left little room to detect a treatment effect.

Practical takeaway: this is a negative but clinically useful trial — it does not support routinely adding timolol gel to standard post-Mohs secondary-intention wound care, and given the drug isn't free of side effects, there's no reason to adopt it as a default based on current evidence. If you've been curious about this off-label practice, this trial is a reasonable basis to not change what you're already doing.

Bundled in that same brief-reports section is a separate single-center retrospective study looking at inpatient hidradenitis suppurativa admissions — worth a quick mention since it's directly relevant to how we counsel patients on disease severity and referral. Over about six years at a single Miami hospital, 44 patients accounted for 83 admissions for HS flares, split roughly evenly between dermatology and internal medicine services. The population skewed young, with a mean age of 38, and the disease was severe — over 80% had Hurley stage three disease, and nearly half had already failed a biologic. Notably, when patients were admitted to a non-dermatology service, dermatology was only consulted about a third of the time. Average length of stay was about a week, most patients got intravenous steroids and antibiotics like ertapenem or vancomycin, and while pain improved in the large majority by discharge, drainage improved in fewer than a third. There's no control group or hypothesis test here — it's descriptive — but the practical signal is that HS inpatient care is inconsistent and dermatology involvement is underutilized, which is a reasonable advocacy point for building better consult pathways at your own institution.

Last, a research letter — not a full study, but a focused correspondence piece — from an Italian group asking whether older age independently predicts recurrence in stage two cutaneous melanoma. The clinical motivation is topical: as adjuvant therapy becomes standard for high-risk resected stage two disease, we need better tools to figure out who within that stage two bucket is actually at highest risk, since stage two survival curves are known to overlap substantially with stage three.

This was a retrospective single-center cohort of 142 patients with stage two melanoma and at least four years of follow-up, further explored with a nested case-control analysis matching recurrent cases to non-recurrent controls by Breslow thickness and ulceration — a smart design choice, because it lets them isolate the independent contribution of age while controlling for the two dominant known prognostic variables, so the age signal isn't just a proxy for thicker or more ulcerated tumors in older patients.

The findings: relapse-free survival was significantly worse in patients 60 and older, with the survival curves separating early and staying separated throughout follow-up. In the matched multivariable analysis, each additional year of age increased recurrence hazard by about 5 to 6%, and this was statistically significant, while sex and tumor location showed no independent association. Recurrences clustered in lymph nodes, cutaneous or subcutaneous sites, and surgical scars, with a mean time to recurrence around a year and a half.

The authors frame this as consistent with immunosenescence — impaired lymph node architecture and antigen presentation in older patients — and they explicitly connect it to other recent work showing sentinel lymph node biopsy is a poor mortality predictor at both ends of the age spectrum. They're upfront about the limitations: small single-center sample and retrospective design.

Practical takeaway: this is interesting and biologically plausible, but not yet practice-changing — it's a single-center retrospective signal, not a validated risk model. It reinforces something many of you probably already sense clinically, that an older patient with a borderline stage two melanoma may warrant closer surveillance or a lower threshold for multidisciplinary discussion about adjuvant therapy, but it shouldn't be read as a mandate to alter staging or treatment algorithms based on age alone yet.

That wraps our four articles for January. A quick synthesis: the cosibelimab data is the one with direct implications for how you counsel and coordinate care for advanced CSCC patients; the sustainability paper offers immediately actionable, zero-cost changes for your own clinic; the timolol trial is useful mainly for telling you what not to bother adding to your wound care routine; and the melanoma age data is a promising but preliminary piece of the risk-stratification puzzle. Thanks for listening, and we'll see you next month.