Australian cancer clinicians and researchers were among the many thousands presenting their study results at the ESMO 2022 meeting held in in Paris recently. These are five higlights from the poster sessions at the ESMO meeting.

Third vaccine dose crucial for cancer patients

An early third Covid vaccine dose is essential to ensure adequate immunity in patients with some cancers, according to Monash researchers led by Prof Eva Segalov.

Their prospective SerOzNET study of 399 patients with cancer (65% solid cancer, 35% haematological cancer) showed that neutralising antibody rates after the second dose of vaccine were 87% for patients with solid cancers and 40% for patients with haematological cancers. The post dose 3 responses were 97% for patients with solid cancer and 70% for haematological cancer patients.

Immunosuppressive drugs, lymphoma and steroids were factors associated with non-response among haematological cancer patients, the study investigators reported.

Patients were also particularly vulnerable if they had ChadOx1-S as the primary vaccine and ECOG status greater than 1, they noted.

The study also showed that the T cell response rate increased after each of the first three doses of Covid vaccine, the increases were similar for patients with solid and haematological cancers.

Autoantibodies are biomarkers for irAE

Pre-treatment serum autoantibodies may be potential biomarkers to predict which patients are at high risk of  immune-related adverse events (irAEs) with checkpoint inhibitors, a WA study has suggested.

Researchers at the Sir Charles Gairdner Hospital in Perth analysed sera from 100 cancer patients before they started on pembrolizukab or nivolumab monotherapy or a combination of ipilumab and nivolumab.

Of the 85 evaluable patients, 60 experienced irAEs, of which a third were grade 3 or 4 severity. The most common adverse events were GI (46%), hepatitis (27%) and endocrine (12%)  irAEs.

A combination of eight IgG and IgA autoantibodies (PCP2, DNTTIP1, GPR152, CYB5R4, FSD1, GTSE1, UR11 and BCOR) was found to be highly predictive of the risk of developing irAEs, regardless of the checkpoint inhibitor regimen.

Further prospective studies are needed to validate the findings, the researchers concluded.

Durvalumab benefits maintained in elderly patients with NSCLC

The efficacy and toxicity of durvalumab are acceptable in elderly patients with unresectable stage III NSCLC following platinum-based chemoradiotherapy (CRT), according to researchers from the Chris O’Brien Lifehouse in Sydney.

A retrospective observational study involving 145 patients who received consolidation durvalumab  showed there was no difference in overall survival between patients over the age of 70 and those under 70 during 19 months of follow up.

And while 95% of patients experienced an adverse events during CRT, there was no link to age or comordities (CCI).

Adverse events from durvalumab were seen in 54% of patients and 15% had grade 3-4 toxicity. Pneumonitis was the most common irAE and 8% of patients had grade 3-5 pneumonitis.

There was no association between age and durvalumab toxicity or treatment discontinuation. However there was increased severe toxicity among patients with more comorbidities (CCI > 5) and a trend towards early cessation due to toxicity.

The findings may be useful to guide risk assessment in this population, concluded the authors, led by Dr Samuel Stevens of the Department of Medical Oncology.

Improved prediction tool for RFS in stage II melanoma patients

Researchers from the Melanoma Institute Australia have developed an improved tool to predict recurrence free survival (RFS) for patients with stage II melanoma that will help guide selection for adjuvant systemic therapy.

Based on a cohort of 3243 patients, the tool was developed to try improve prediction of survival for sentinel node negative Stage IIb/C melanoma receiving adjuvant pembrolizumab.

The tool inputs included age, Breslow thickness, , ulceration, gender, body site, mitoses, satellites, TILs, regression and Sentinal Node status.

The MIA model showed good discrimination and calibration to predict survival for individual stage II melanoma patients at both five and ten years, with significant discrimination gains over the AJCC-8 stage groups.

The researchers’ led by Associate Professor Alex Carey said the model would provide clinicians with important data to guide recommendations for adjuvant immunotherapy, based on individual patients’ risk-benefit ratios. An online tool will be available at www.melanomarisk.org.au.

Lipid profiling may help mCRPC patients

Australian researchers have developed a plasma lipid biomarker assay that can identify men with metastatic castration resistant prostate cancer (mCRPC) who have a poor prognosis and who may be candidates for therapies targeting lipid metabolism, such as the SPHK2 inhibitor opaganib.

A team at Sydney University analysed total cholesterol, triglycerides and HDL levels in a cohort of more than 100 male patients with mCRPC who were treated with docetaxel. They identified a specific lipid profile that was associated with patients who had  a significantly shorter overall survival compared to those who did not score highly for the profile. The hazard ratio for a positive vs negative score was 3.75 (p < 0.001).

The predictive value of the lipid profile was validated in a further cohort of more than 180 mCRPC patients who were treated with agents including enzalutamide and abiraterone.

The five lipids in the PCPro assay remain commercial in confidence, according to researchers led by Dr Tahlia Scheinberg of the Department of Medical Oncology, Chris O’Brien Lifehouse, Sydney.