Poster Presentation 2025 Joint Meeting of the COSA ASM and IPOS Congress

Radioprotective effects of parthenolide lotion against skin injury caused by radiation (REPAIR-1): protocol for a phase 0, non-randomised, double-blind, interventional pilot study (125911)

Connor Williams 1 2 , Katherine Morel 3 , Agnieszka Kumorkiewicz-Jamro 3 , Daniel Johnstone 4 , Hien Le 5 6 , Christopher Sweeney 3 , Hannah Wardill 1 2
  1. The University of Adelaide, Adelaide, SA, Australia
  2. Precision Medicine (Cancer) Theme, Supportive Oncology Research Group, The South Australian Health and Medical Research Group, Adelaide, South Australia
  3. South Australian Immunogenomics Cancer Institute, The University of Adelaide, Adelaide, South Australia
  4. University of South Australia, Adelaide
  5. Department of Radiation Oncology, Central Adelaide Local Health Network, Adelaide, Australia
  6. Allied Health and Human Performance, University of South Australia, Adelaide, South Australia

Background: Radiation forms the basis of many successful anti-cancer treatment regimens, however through the nondiscriminatory killing healthy cells, it drives a range of debilitating and highly impactful side effects. One of the most common side effects is radiation-induced dermatitis (RID), occurring in up to 95% of people undergoing radiation therapy. Although common, RID cannot be prevented and is inadequately managed with various topical solutions. Parthenolide has emerged as a promising radioprotective agent for the management of RID. The REPAIR-1 study is a phase 0, prospective, non-randomised, double-blind, interventional pilot study which aims to assess the efficacy of topical parthenolide application in limiting severe RID.

Methods: The REPAIR-1 study is being conducted at the Royal Adelaide Hospital, South Australia, Australia. Eligible participants for the REPAIR-1 study include adults diagnosed with locally advanced cancer of the head/neck scheduled to receive definitive, bilateral radiation therapy. Once enrolled, eligible participants will receive application of a 1% parthenolide, or placebo lotion, to opposite sides of the head/neck region before and after daily radiation therapy for the duration of their treatment course (6-7 weeks). The primary outcome of this study is absolute RID severity after 4 weeks of radiation therapy defined by both CTCAE v5.0 criteria and the RISRAS tool.

Results: The REPAIR-1 study (ACTRN12625000456459) is active, with a recruitment target of N=10 by Q4 2025.

Conclusion and clinical implications: This study aims to establish the feasibility and efficacy of topical parthenolide application as a radioprotective agent, aiming to offer a mechanistically novel approach to prevent RID whilst still ensuring radiation efficacy.