Melbourne-Developed Drug Delivery Platform Delivers ‘Impressive' Results In International Bowel And Ovarian Cancer Trial

A ground-breaking nanoscale drug delivery technology used to enhance the safety and performance of cancer drugs has been credited with “impressive” results in two of Australia’s most common cancers – colorectal (bowel) and ovarian cancer.

Developed at its Abbotsford laboratory by biotech company Starpharma, the technology known as DEP (Dendrimer Enhanced Product) utilises nanoscale polymers called dendrimers to improve the effectiveness and safety of cancer drugs.

Starpharma will present the clinical data for its DEP version of the widely-used drug irinotecan – marketed as Camptosar - at a key international oncology conference in Boston in October along with Dr Jenny Liu, Medical Oncologist and Principal Investigator at the Kinghorn Cancer Centre at St Vincent’s Hospital in Sydney.

Starpharma’s DEP irinotecan demonstrated durable anti-tumour responses in very heavily pre-treated advanced colorectal (bowel) cancer patients and platinum-resistant/refractory ovarian cancer patients and was very well tolerated. These impressive results were generated even though 97% of the bowel cancer patients in the study had already been treated with conventional irinotecan.

Dr Liu said the interim results in the Phase 2 trial of DEP irinotecan on patients who had exhausted all available standard-of-care therapies were very promising.

“The results of the DEP irinotecan trial to date have been very promising for patients with advanced colorectal cancer who have exhausted standard treatment options, with prolonged responses and excellent tolerance of the product, including in patients who could not previously tolerate standard irinotecan or had failed prior therapy”, Dr Liu said.

Dr Liu will present the data at the high-profile International Conference on Molecular Targets and Cancer Therapeutics, co-hosted by the American Association of Cancer Research, in Boston next month.

UK Medical Oncologist and study Principal Investigator at the leading international cancer hospital, The Christie, Dr Natalie Cook, was also impressed with Starpharma’s DEP irinotecan.

“I am impressed with the data on Starpharma's novel dendrimer formulation of irinotecan. In our patients, DEP irinotecan has shown excellent tolerability and very encouraging efficacy. Compared to conventional irinotecan, tolerability for DEP irinotecan is much improved. Based on the data, I believe DEP irinotecan represents a well-tolerated and promising treatment alternative for patients with colorectal and platinum-resistant ovarian cancer”, Dr Cook said.

Starpharma CEO Dr Jackie Fairley said the upcoming international oncology conference in Boston represents an excellent opportunity to showcase DEP irinotecan and the benefits the DEP technology delivers for patients with bowel cancer and ovarian cancer.

“We are pleased to report these very positive results for DEP irinotecan, which has shown promising activity and significantly improved tolerability in advanced colorectal cancer and ovarian cancer patients who were very heavily pre-treated. The conference in October is an excellent opportunity to highlight DEP irinotecan and Starpharma’s DEP platform more broadly.

“Starpharma has received consistent feedback from patients and clinicians that DEP irinotecan represents a better-tolerated treatment option than conventional irinotecan regimens, a mainstay therapy in colorectal cancer.”

In the trial, advanced colorectal cancer patients treated with DEP irinotecan achieved durable efficacy responses for up to 72 weeks, with disease control in 48% of evaluable patients. This was despite all but one of the patients (97%) having previously had their colorectal cancer relapse following treatment with standard irinotecan.

One of those undertaking the trial was a woman in her late 30s with stage 4 colorectal (bowel) cancer. Before the trial, she had 16 cycles of two different treatment regimens in addition to surgery and radiotherapy. Following treatment with DEP irinotecan, she achieved a 31% reduction in the combined size of all tumour lesions and more than 70% reduction in tumour biomarkers.

Camptosar and generic forms of conventional irinotecan are standard-of-care treatments for advanced colorectal (bowel) cancer, with Pfizer’s Camptosar achieving peak sales of around $US1.1B. However, about 47% of patients treated with conventional irinotecan suffer problematic adverse reactions to the drug, including acute diarrhoea, excessive sweating, slow heartbeat, low blood pressure, increased salivation, blurred vision, flushing, and abdominal cramping. Because of the severe side effects it causes, Camptosar and all generic forms of conventional irinotecan must carry “black box” warnings mandated by the FDA in the US.

Bowel cancer is the third most common cancer worldwide; worryingly, it is increasing significantly in younger age groups. Bowel Cancer Australia says bowel cancer in young people has increased by 266% worldwide since the 1980s, with one in every ten new cases now involving someone under 50. According to the World Health Organisation (WHO), an increase of about 70% in colorectal cancers globally is expected by 2030.

Patients with advanced ovarian cancer were also treated in Starpharma’s DEP irinotecan trial. These patients were also heavily pre-treated, having received an average of approximately six prior treatment regimens before this study and exhausted all available treatment options. All ovarian cancer patients in this study were also resistant or refractory to platinum-based therapies, the standard-of-care in ovarian cancer.

Despite this, patients treated with Starpharma’s DEP irinotecan achieved positive responses, including tumour shrinkage of up to 60%, response durations of up to 36 weeks, and tumour biomarker reductions of up to 98% in more than 75% of patients.

One of those undertaking the trial was a woman in her 70s with heavily pre-treated, advanced platinum-resistant ovarian cancer. Before the trial, the woman had extensive surgery and 39 treatment cycles with five different anti-cancer therapies. Following treatment with DEP irinotecan, the woman saw a 60% reduction in the combined size of all her tumour lesions and up to 52% reduction in her tumour biomarkers.

The Starpharma DEP irinotecan trial is being conducted across multiple international sites including the Kinghorn Cancer Centre in Sydney, the Christie Hospital in Manchester, Guy’s Hospital in London, the Beatson Cancer Centre in Glasgow, and the Imperial College in London.

Starpharma is a world leader in dendrimer technology for medical applications. As an innovative Australian biopharmaceutical company, Starpharma is focused on developing and commercialising novel therapeutic products that address significant global healthcare needs.

The Company reported positive data from its clinical trial of DEP cabazitaxel in prostate cancer late last year and promising preclinical results in the radiodiagnostics field more recently. Starpharma also markets VIRALEZE™ Antiviral Nasal Spray and VivaGel BV in more than 35 countries globally.