Cisplatin works. That is both its value and its problem.
The chemotherapy drug has been a cornerstone of treatment for childhood solid tumors for decades. It is effective against a wide range of cancers including hepatoblastoma, neuroblastoma, and osteosarcoma. It is also one of the most reliably ototoxic drugs in oncology, meaning it damages the cells of the inner ear and causes permanent hearing loss in a significant proportion of the children who receive it.
Studies published in the New England Journal of Medicine and Lancet Oncology put the rate of cisplatin-induced hearing loss in children at between 40% and 60% depending on dose and age. For a child treated at age three, that hearing loss will affect speech development, language acquisition, educational progress, and social functioning for the rest of their life. Until recently, there was nothing clinicians could do about it except choose lower doses and accept reduced cancer-fighting efficacy.
On May 5, 2026, Norgine announced that PEDMARQSI (sodium thiosulfate anhydrous) has been registered by Australia’s Therapeutic Goods Administration for the prevention of cisplatin-induced hearing loss in patients aged one month to under 18 years with localised, non-metastatic solid tumours. It is the first and only treatment registered in Australia specifically for this purpose.
What sodium thiosulfate does and why the timing matters
Sodium thiosulfate is not a new compound. It has been used clinically for decades in other contexts including cyanide poisoning treatment. What PEDMARQSI represents is a specifically developed formulation and dosing regimen designed to be administered after cisplatin infusion in a way that neutralizes residual cisplatin in the cochlea without interfering with its anti-cancer activity in the tumor.
The mechanism exploits a difference in blood flow between the tumor and the inner ear. After cisplatin is administered, sodium thiosulfate given intravenously binds to and inactivates cisplatin that has distributed to the cochlea, where the drug’s ototoxic damage occurs. The timing of administration is critical: given too early, sodium thiosulfate could reduce cisplatin’s effectiveness against the tumor. Given after a defined delay, it selectively protects the ear.
The two Phase 3 trials underpinning the TGA registration, SIOPEL 6 published in the New England Journal of Medicine in 2018 and COG ACCL0431 published in Lancet Oncology in 2017, demonstrated that sodium thiosulfate administered after cisplatin significantly reduced the rate of hearing loss without compromising cancer outcomes in children with localised solid tumors. Those results were the basis for the European Medicines Agency’s Paediatric Use Marketing Authorisation granted in May 2023, UK national authorization, and Swissmedic approval in March 2026.
Australia is the latest jurisdiction to complete that regulatory journey.
The reimbursement gap and what it means for access
PEDMARQSI is not listed on Australia’s Pharmaceutical Benefits Scheme. The same situation exists with NIKTIMVO, which we covered in a recent article. TGA registration authorizes prescribing. PBS listing makes the drug accessible at subsidized prices for the patients who need it.
For a drug treating children with cancer in a relatively small eligible patient population, PBS listing requires the Pharmaceutical Benefits Advisory Committee to assess cost-effectiveness against a standard that accounts for the rarity of the condition and the severity of the complication being prevented. Given that the alternative to treatment is permanent hearing loss in children, the clinical case for listing is strong. The commercial negotiation on price is the variable.
According to the Children’s Cancer Institute Australia, approximately 950 children are diagnosed with cancer in Australia each year, with a subset receiving cisplatin as part of their treatment regimen. The eligible population for PEDMARQSI is relatively small in absolute terms but highly concentrated in one of the most vulnerable patient populations in oncology.
For families navigating pediatric cancer treatment, the addition of an approved preventive option for one of chemotherapy’s most significant long-term side effects is meaningful in a way that extends well beyond the clinical trial data.
Sources
- New England Journal of Medicine — SIOPEL 6 Trial
- Lancet Oncology — COG ACCL0431 Trial
- Children’s Cancer Institute Australia
- Norgine — Official Website
Editorial disclosure
This article is based on a press release issued by Norgine and has been independently rewritten and editorially expanded. It covers TGA registration of PEDMARQSI for the prevention of cisplatin-induced hearing loss in paediatric patients in Australia. Norgine is a privately held European specialty pharmaceutical company. PEDMARQSI is not listed on Australia’s Pharmaceutical Benefits Scheme. PBS listing is being pursued separately and is not guaranteed. This article does not constitute medical advice. Market context is sourced from the Children’s Cancer Institute Australia and peer-reviewed clinical trial publications. Commentary reflects the author’s own assessment. The information provided on this website is for informational and educational purposes only. Our content is derived strictly from verified online sources to ensure accuracy and objectivity. This analysis does not constitute financial, investment, or professional advice. Readers are encouraged to consult with qualified professionals before making decisions based on this information. For more information, please see our full DISCLAIMER.
