|Using resiquimod on some CTCL legions has a systemic effect, |
which can be seen in significantly diminished legions that did
not directly receive treatment. (Credit: Penn Medicine)
Results of a phase one trial show that an investigational topical drug, resiquimod gel, causes regression of both treated and untreated tumor lesions and may completely remove cancerous cells from both sites in patients with early stage cutaneous T cell lymphoma (CTCL) - a rare type of non-Hodgkin lymphoma that affects the skin. Currently, there is no cure for CTCL aside from a bone marrow transplant. However, the new study shows that the topical gel can eliminate malignant T cells, leading to diminished lesions. The study is published in the journal Blood.
In the trial, twelve patients who had previously undergone an average of six treatments for early stage CTCL were treated with topical resiquimod gel at varying doses and intervals. Patients applied specified doses (0.03 percent of 0.06 percent) to select skin lesions for 16 weeks. However, some patients using the 0.06 percent dose showed a full clearing of all malignant cells after only eight weeks.
By the final evaluation, treated lesions were significantly improved in 75 percent of patients, and 30 percent saw full resolution in all treated lesions. Unlike other treatments, resiquimod also improved untreated lesions, resulting in more than 50 percent improvement for more than 90 percent of patients. Two participants, one of whom had been living with CTCL for more than 15 years without response to treatment, saw full eradication of the disease.
Using a method known as high throughput sequencing (HTS), the team was able to determine how many distinct malignant cells were present within a sample of healthy cells. The technique showed it could identify a single malignant cell amongst 100,000 healthy cells. DNA from biopsies of the same treated lesion were analyzed before treatment and eight weeks after treatment began to identify the number of malignant T cells. The percentage of malignant T cells was reduced significantly in nine of ten tested participants, three of whom had complete eradication of the malignant population, and one of whom had a 99.6 percent reduction.
Further research with larger participant populations is needed to determine the best approach and application.
Based on material originally posted by University of Pennsylvania School of Medicine.