CLINUVEL today announced that it has reached agreement with clinical and academic experts to expand its DNA Repair Program to patients diagnosed with xeroderma pigmentosum-variant (XP-V). The Program commenced in 2020, evaluating SCENESSE® (afamelanotide 16mg) in XP-C patients.“The progression of making afamelanotide available to a further group of XP patients, who are extremely affected by ultraviolet (UV) and sun damage, is logical,” CLINUVEL’s Clinical Operations Manager, Dr Pilar Bilbao said. “We had identified that both XP-C and XP-V patients are most likely to benefit from the hormonal therapy we have developed. “The drug’s benefit will be analysed by observing these patients’ skin reactions to UV light and by analysing markers in skin samples such as pyrimidine dimers, which really are indicators of the inability to repair damaged strands of DNA. Given our pioneering work on providing systemic photoprotection, we are in the best position to make a positive impact on XP patients’ lives.” Dr Bilbao said.
XP-V VERSUS XP-C
Clinically, it is apparent that both XP-V and XP-C populations are extremely prone to developing skin cancers. In XP-C patients a defect in a DNA repair mechanism (nucleotide excision repair or NER) directly leads to skin cancers. XP-V patients have a genetic defect (POLH gene) leading to an increase of mutations, giving rise to phototoxicity and increased risk of skin carcinogenesis.
XP-V and XP-C comprise an estimated 20% and 40%, respectively, of the global XP patient population. The prevalence of XP-V ranges from 1:450,000 to 1:1,000,000 worldwide.
CLINICAL TRIAL PROGRAM (CUV150 TO CUV153), DNA REPAIR
CLINUVEL’s current DNA Repair Program aims to confirm the clinical effect of SCENESSE® in assisting the protection and regeneration of DNA in XP patients, with healthy volunteers of fair skin complexion serving as a control group. Treated groups will receive afamelanotide either every one, two, or three weeks for a duration of up to four months. Skin samples (biopsies) of exposed skin areas will be taken for laboratory analyses of DNA damage before and after drug administration. Patients will be frequently monitored, including complete skin examinations before and during treatment. Quality of life questionnaires will assist in evaluating the possible impact of the treatment on patients’ wellbeing. The first XP-C patient was treated with SCENESSE® under a Special Access Program in 2020. No significant or notable adverse events were observed or reported by the expert clinical centre responsible for medical care.
| Clinical Trial | Phase | Target Population | Participants |
|---|---|---|---|
| CUV150 | Phase IIb | XP-C | n = 6 |
| CUV151 | Phase II | Healthy Volunteers | n = 10 |
| CUV152 | Phase IIb | XP-C & XP-V | n = 6 |
| CUV153 | Phase II | XP-V | n = 6 |
Depending on ongoing COVID restrictions in leading university hospitals, the Ethics Committees and hospital administrations are expected to allow the start of the XP studies once the risk of infection is assessed as acceptable. A limited number of clinical trials have been conducted with XP patients, and there is currently no efficacious therapy available for them.
Authorities carefully evaluate the requests of a pharmaceutical company seeking permission to subject these high-risk patients to a possible drug therapy, and it is especially important in these patients, given the high mortality and morbidity of XP patients. Various clinical centres and authorities have responded positively to CLINUVEL’s XP program.
SCENESSE® MODE OF ACTION
Afamelanotide’s clinical mode of action provides anti-oxidation, vascular activity, reduction of tissue fluid, and improvement of inflammatory signs. To provide its pharmacological activity, the drug binds to a number of human cells, predominantly to the melanocortin-1 and melanocortin-4 receptors (MC1R and MC4R).
Importantly, afamelanotide offers systemic photoprotection by preventing photodamage and improving the regeneration of skin cells. Clinically, afamelanotide has been confirmed to show reduction of DNA damage caused by UV radiation and visible light (oxidative damage and pyrimidine dimers). Further research has shown the ability of afamelanotide and other melanocortin molecules to assist skin cells in DNA repair mechanisms (NER).