Peter Mac research has been well-represented at the American Association of Cancer Research (AACR) Annual Meeting, held in New Orleans last week.

Lead genitourinary medical oncologist Associate Professor Ben Tran gave a prestigious oral presentation at one of the conference's plenary sessions about an exciting new compound called MEDI5752.

MEDI5752 is being evaluated in a first in human phase 1 clinical trial to see how safe and effective it is in adults with advanced solid tumours.

"MEDI5752 is an antibody that targets both PD-1 and CTLA-4 at the same time; these proteins are the key brakes that prevent immune cells from targeting cancers in some patients," Associate Professor Tran says.

In the study he presented, MEDI5752 resulted in substantial immune cell activation exceeding what is achievable with the current therapies in use.

Additionally, MEDI5752 resulted in tumour shrinkage that was seen across a diverse range of tumours, and at multiple dose levels.

"So far, the trial is showing encouraging anti-tumour activity and longer term clinical benefits for patients," Associate Professor Tran says.

There were also two other clinical trial plenary presentations at AACR from trials conducted by Peter Mac investigators in the Early Drug Development trials program.

Medical oncologist Dr Stephen Luen was last author on interim results presented from the ongoing PETRA trial, a first in human phase 1/2a clinical trial of AZD5305, a new generation PARP1-selective PARP inhibitor.

PARP1 is an enzyme that allows cells to repair DNA damage. By blocking this enzyme in cancer cells, PARP1 inhibitors can prevent the cells repairing themselves and hence cause them to die.

Results from PETRA show AZD5305 is better tolerated and more effective in patients with advanced breast, ovarian, prostate or pancreatic cancer who also carry certain genetic mutations, than first generation inhibitors.

Medical oncologist Associate Professor Jayesh Desai was a co-author on an analysis of the long-term efficacy data from the breakthrough KRAS-G12C inhibitor sotorasib in patients with non-small cell lung cancer.

KRAS is a protein that when it is switched on, controls how often a cell divides. A mutated form of this protein KRAS-G12C is always switched on, meaning cells are more likely to divide uncontrollably leading to the formation of tumours.

Forty per cent of patients given sotorasib responded to the therapy, and kept responding for a median duration of just over a year. Importantly, the one and two-year overall survival of patients was 50.8 per cent and 30.3 per cent respectively.

"Trials into this first-in class agent, next-generation KRAS G12C inhibitors and combination strategies are an area of strong research focus for Peter Mac investigators," Associate Professor Desai says.

Medical oncologist Associate Professor Jeanne Tie chaired and presented at an education session about minimal residual disease in solid tumours.

The session provided an overview of the current evidence, the challenges of minimal residual disease detection in solid tumours, clinical implications, and the roadmap to demonstrating clinical utility.

Medical oncologist Professor Sarah-Jane Dawson ran a Meet the Expert session on circulating tumour DNA – small fragments of cancer DNA in a patient's blood.

This followed on from Professor Dawson's 2021 AACR oral presentation on how liquid biopsies – a type of blood test – could be refined to identify circulating tumour DNA, allowing for earlier cancer diagnosis and better tailored treatments.

A number of presentations also showcased the strength of prostate cancer research at Peter Mac.

  • Associate Professor Shahneen Sandhu presented a poster on molecular subtyping of prostate cancer to better understand the underlying disease biology.
  • Dr Luc Furic presented at a minisymposium about PMR-116, a new inhibitor of ribosome biogenesis (ribosomes regulate protein synthesis) which shows promising results in preclinical models of prostate cancer. PMR-116 is now in a first in human Phase 1 trial at Peter Mac for patients with solid tumours.
  • Dr Heidi Fettke presented a poster on preliminary results from an Australian study looking at circulating tumour DNA and outcomes following Lutetium-PSMA treatment in patients with advanced prostate cancer.
  • PhD student Rosalia Quezada Urban presented a poster on how single cell RNA analysis revealed a number of distinct subpopulations of cells in aggressive variants of prostate cancer.

Read more about all the Peter Mac research presented at the AACR Annual Meeting on the conference website.