MSD’s precision medicine to change bowel cancer prognosis

Pharma News: Australians with a specific type of bowel cancer are no longer subject to a ‘one-size fits all’ treatment approach, with immuno-oncology therapy KEYTRUDA (pembrolizumab) now available as a treatment option.

MSD announced the TGA registration of KEYTRUDA for the first-line treatment of patients with unresectable or metastatic colorectal cancer that have a specific alteration called microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR), as determined by a validated test.

KEYTRUDA is a cancer immunotherapy that works to reactivate the immune system to attack tumour cells by blocking a cancer cell protein (known as programmed death receptor 1 or PD-1) which left unchecked allows cancer cells to pass undetected by the body’s natural defences.

MSD has made a submission to the Pharmaceutical Benefits Advisory Committee (PBAC) for reimbursement of the treatment, for mismatch repair deficient (dMMR) metastatic colorectal cancer (a specific type of bowel cancer), which will be considered by the PBAC at the upcoming meeting in March 2021.

Australian patients, carers and the community can currently submit a ‘consumer comment’ to the PBAC by 10 February with their views regarding the availability and access of this treatment for eligible patients.

This latest indication for metastatic bowel cancer provides another option for Australian patients.  An estimated 15,000 Australian patients will be diagnosed with bowel cancer each year – the fourth most commonly diagnosed cancer in Australia; and in 2020, there were an estimated 5,300 deaths from bowel cancer in Australia – making bowel cancer the second leading cause of cancer death in Australia.

Julien Wiggins, CEO Bowel Cancer Australia, welcomed KEYTRUDA as a treatment option for this for this subset of bowel cancer patients: “While there is a lot of important discussion regarding bowel cancer screening, treatment options remain vital. Up to half of the 15,000 Australians diagnosed with bowel cancer each year already have metastatic disease or will go on to develop it.”

“While bowel cancer is considered a common cancer, rare subtypes exist. Eligible patients with certain types of cancer, including melanoma and non-small cell lung cancer, already have reimbursed PBS access to immuno-oncology medicines.”

A small number of bowel cancers have a biomarker (mismatch repair deficiency – dMMR or Microsatellite Instability-High – MSI-H) which helps in identifying patients that may respond to immuno-oncology therapies such as KEYTRUDA. This biomarker may also provide information on the likely course of disease in an untreated patient with bowel cancer. Testing for this biomarker in bowel cancer is already standard practice in Australia but there were previously no alternative treatment options, or treatment options that matched this specific biomarker for Metastatic colorectal cancer patients, until now.

Professor Peter Gibbs, from Western Health in Melbourne, specialises in treating patients with bowel cancer and was a co-author for the publication of the MSD-sponsored clinical trial in this indication in the December 2020 edition of the New England Journal of Medicine “Australians with bowel cancer are tested for this rare biomarker called mismatch-repair deficiency (dMMR) or Microsatellite Instability-High (MSI-H), and approximately 6.9 percent of patients at the metastatic stage will have this marker. Knowing this information helps us to appropriately guide their treatment journey and provide the right options for the right patients.

“This treatment is a form of personalised medicine for the treatment of bowel cancer for eligible patients and enables us to finally move away from a ‘one-size fits all’ approach to treating these patients. It gives these seriously ill patients more hope,” continued Professor Gibbs.

“It’s availability in Australia has been eagerly anticipated across the medical community and bring us one step closer to ensuring this treatment is soon available for patients on the PBS.”

MSD Managing Director for Australia and New Zealand, Mr Michael Azrak, said this latest registration for KEYTRUDA is the therapy’s 17^th indication on the ARTG1 and cements the place of KEYTRUDA as a treatment option for eligible Australian bowel cancer patients.

“This indication is a new oncology milestone for Australian patients and clinicians. Health Technology Assessment reform, however, is needed in Australia to improve alignment between Therapeutic Goods Administration (TGA) and PBAC processes so that eligible Australian patients can access these medicines as quickly as possible.

“The TGA registered this indication in six months, three months earlier than expected, via their priority pathway and in collaboration with international regulatory agencies (US, Switzerland and Canada) through Project Orbis. However, registration is only the first step. Timely and affordable access, through reimbursement on the Pharmaceutical Benefits Scheme, is our goal for these patients. We believe that this indication provides a high-added therapeutic value to Australian patients, and we hope that the PBAC also recognises the value of this treatment for eligible bowel cancer patients,” said Mr Azrak.