Vaccination with photodynamic therapy-treated macrophages induces highly suppressive T-regulatory cells

Evaluation of Low-Dose, Low-Frequency Oral Psoralen-UV-A Treatment With or Without Maintenance on Early-Stage Mycosis Fungoides: A Randomized Clinical Trial

Importance

Psoralen-UV-A (PUVA) photochemotherapy is standard first-line treatment for skin-limited, early-stage mycosis fungoides capable of producing high initial complete response (CR) rates. However, much remains unknown about PUVA's therapeutic mechanisms, optimal duration and frequency of treatment, dose escalation, or use as maintenance therapy.

Objectives

To evaluate low-dose, low-frequency PUVA, and whether maintenance treatment extends disease-free remission in patients with mycosis fungoides.

Design, Setting, and Participants

This prospective randomized clinical trial with defined PUVA dosing regimen was carried out in 5 centers (Graz, Vienna, Hietzing, Innsbruck, and Salzburg) across Austria. Patients with stage IA to IIA mycosis fungoides (n = 27) were enrolled in the study beginning March 13, 2013, with the last patient enrolled March 21, 2016. These patients were treated with oral 8-methoxypsoralen followed by UV-A exposure 2 times per week for 12 to 24 weeks until CR. Patients with CR were randomized to PUVA maintenance for 9 months (14 total exposures) or no maintenance. The study was conducted from April 27, 2012, to July 27, 2018. Data analysis of the primary end point was of the intention-to-treat population, and the secondary end point analysis was of the evaluable population.

Main Outcomes and Measures

Efficacy of the PUVA regimen was determined by the rate of CR as defined by a modified severity-weighted assessment tool (mSWAT) score reduction to 0. Levels of proinflammatory molecules in serum and histologic features and percentage of clonal T cells in skin were assessed to search for biomarkers of clinical response.

Results

In 27 patients with mycosis fungoides, 19 (70%) were male with mean (range) age 61 (30-80) years. At baseline, patients with CR had a mean (range) mSWAT score of 18.6 (1-66) compared with 16.8 (3-46) in patients with partial response. The 12- to 24-week PUVA induction regimen reduced the mSWAT score in all patients and led to CR in 19 (70%) of 27 patients and a low mean cumulative UV-A dose of 78.5 J/cm2. The subsequent standardized 9-month PUVA maintenance phase prolonged median (range) disease-free remission from 4 (1-20) months to 15 (1-54) months (P = .02). High density of histologic infiltrate and high percentage of clonal TCR sequences in skin biopsy specimens at baseline were inversely associated with therapeutic response. No severe adverse effects were seen during the PUVA induction or maintenance phase.

Conclusions and Relevance

This proof-of-concept study identifies potential biomarkers for therapeutic response to PUVA in mycosis fungoides; it also demonstrates that low-dose, low-frequency PUVA appears to be highly effective, and maintenance treatment may extend disease-free remission.

Trial Registration

ClinicalTrials.gov identifier: NCT01686594.

Ultrafast laser-assisted spatially targeted optoporation into cortical axons and retinal cells in the eye

Visualization and assessment of the cellular structure and function require localized delivery of the molecules into specific cells in restricted spatial regions of the tissue and may necessitate subcellular delivery and localization. Earlier, we have shown ultrafast near-infrared laser beam-assisted optoporation of actin-staining molecules into cortical neurons with single-cell resolution and high efficiency. However, diffusion of optoporated molecules in soma degrades toward the growth cone, leading to difficulties in visualization of the actin network in the growth cone in cases of long axons. Here, we demonstrate optoporation of impermeable molecules to functional cortical neurons by precise laser subaxotomy near the growth cone, leading to visualization of the actin network in the growth cone. Further, we demonstrate patterned delivery of impermeable molecules into targeted retinal cells in the rat eye. The development of optoporation as a minimally invasive approach to reliably deliver exogenous molecules into targeted axons and soma of retinal neurons in vivo will enable enhanced visualization of the structure and function of the retina.