EORTC studies were well-represented at this year’s ASCO conference, which took place from 4 – 8 June. Seven abstracts were accepted, four for oral presentation, two as posters, and one for online publication. “This is an impressive confirmation of the high quality and clinical importance of our international, patient-centred, academic trials,” said EORTC Director General Dr Denis Lacombe.
Two oral presentations on Sunday described new results from trials in melanoma and in breast cancer. In the first, Professor Alexander Eggermont presented data from the Phase 3 double-blind KEYNOTE trial, which evaluated pembrolizumab vs. placebo in stage III cutaneous melanoma patients with complete resection of lymph nodes. A subgroup of patients in the trial who had had a recurrence or crossed over from placebo were evaluated and followed as integral part 2 of the protocol. For the 155 patients who crossed over from placebo the 3-Year PFS rate was about 32% and the median PFS was 8.5 months. The 1-Year PFS rate for rechallenged patients was 4 months. The outcome of Pembrolizumab after cross over is in line with previous findings. Treatment activity for re-challenged patients is low.
The second, from Dr Josephine Lopes Cardozo, presented findings on the outcome of patients with an ultra-low risk 70 gene signature in the MINDACT trial. Of the 6,693 breast cancer patients enrolled in the trial, genomic profiling revealed that 1,000 of them were at ultra-low risk of distant recurrence. These patients were followed up for over eight years and results showed the accuracy of the prognosis. They had a breast cancer specific survival of 99.6% regardless of their clinical risk status, and an eight-year distant metastasis-free interval of 97.6%. This result implies that they may be candidates for a further de-escalation of treatment, with a reduction in side effects, the researchers say.
Monday saw an oral presentation of a study on newly diagnosed glioblastoma from Dr Patrick Roth, in which 749 newly diagnosed patients were randomised to receive the standard postoperative treatment of radiotherapy plus temozolomide chemotherapy, or standard treatment plus marizomib. Marizomib is a novel pan-proteasome inhibitor that has had encouraging results in Phase I and II studies. Enrolment started in June 2018 and was intended to include 750 patients, but was halted in September 2020 on the recommendation of the independent data monitoring committee. Results showed that the addition of marizomib to standard treatment did not improve either progression-free or overall survival, and that adverse events, particularly psychiatric and neurotoxicities, were higher in those who received it.
Tuesday’s oral presentation was from Professor Silke Gillessen, who reported on a study of the use of enzalutamide alone or in combination with Radium 223 (RA223) in asymptomatic or mildly symptomatic castration-resistant prostate cancer patients, together with the effect of bone-protecting agents (BPAs). Skeletal fractures are a common adverse effect of systemic treatment for advanced prostate cancer, and as a result, BPAs have recently been recommended. 136 patients randomized after mandating BPAs are part of the safety analysis. At one year without BPA, those in the enzalutamide alone group had a 15.6% risk of fracture, and those in the combined group 37.1%, whereas for those who had received a BPA the risks were almost abolished – 2.6% and 2.7% respectively. The results confirm the importance of using BPAs in these patents, say the researchers.
Two posters from EORTC sarcoma trials also featured at the conference. In the first, Dr Rick Haas and colleagues reported on quality assurance results from the STRASS trial, which looked at the impact of the addition of neoadjuvant radiotherapy to surgery alone in patients with retroperitoneal sarcoma. Radiotherapy was the experimental treatment in the trial, and therefore a quality assurance analysis was important to identify and correct potential deviations from the protocol. The researchers found that over 75% of patients had compliant radiotherapy plans, and that this had significant benefit in terms of abdominal recurrence-free survival as well as overall survival as opposed to the non radiotherapy compliant group. The researchers believe that it is the first quality assurance evaluation of a Phase III sarcoma trial and shows the benefit of quality assurance analyses in radiotherapy.
In a second poster, Dr Roberta Sanfilippo and colleagues presented results from a Phase II trial of cabazitaxel in patients with metastatic or inoperable locally advanced dedifferentiated liposarcoma. The study was devised to examine whether capazitaxel demonstrated sufficient anti-tumour activity in these patients to warrant further investigation in a Phase III trial. Eligible patients were treated with cabazitaxel infusions over one hour every 21 days. Out of the 38 patients enrolled, 21 were progression-free after 12 weeks of treatment. The results of the trial confirm the activity of cabazitaxel, say the researchers, and merit further investigation.
Finally, an abstract published online reports on a mapping exercise carried out by Mrs. Claire Piccinin and colleagues, who set out to link items In the EORTC patient-reported outcomes library with their clinical adverse event equivalents. Analysis showed that the EORTC library provides broad coverage of the common terminology criteria for adverse events (CTCAE) symptomatic toxicities, along with other issues such as emotional wellbeing. Therefore, use of the EORTC library can be complementary to CTCAE and classifying patient-reported outcomes following the CTCAE clinical framework will facilitate the use of patient-reported outcomes in trials and clinical care in the future, they say.
“These studies, which have brought together researchers from countries worldwide, have the potential to improve patient care in a significant fashion and to inform practice. We hope that their presentation at the world’s largest oncology conference will contribute to advancing knowledge in oncology” said Dr Lacombe.