Australian oncologists have significantly divergent views on the place of durvalumab in treating Stage III lung cancer, which is reflected in their ‘variable’ prescribing practices, survey data show.

The almost polar opposite responses given by the oncologists highlight the need for local practice guidelines for the PD-1 checkpoint inhibitor, the researchers say.

Some 32 local medical oncologists specialising in thoracic cancer answered the poll between May and July last year about their prescribing for patients with various subcategories of stage III unresectable disease.

Only two (6%) stated they prescribed durvalumab for all patients with EGFR-mutations, while another two respondents said they strongly recommended treatment in this group.

On the other hand, 44% suggested there was “little benefit” of consolidation durvalumab in the EGFR cohort, with an additional 19% advocating for observation only.

There was also a wide variance in oncologists’ positions on use of the drug in patients with PD-L1 negative NSCLC: 13% prescribed it for all such patients, while an additional 56% strongly recommended treatment. But here too, a significant number took the opposite approach.

But this was variability was no sign that any doctor had ‘gone rogue’, stressed the researchers, all oncologists from hospitals in Western Sydney.

Indeed, international guidance was itself heavily conflicted, they wrote in Oncology (link here).

In particular ASCO guidelines advocated for consolidation durvalumab in unresectable stage III NSCLC irrespective of their PD-L1 expression and mutation status. But ESMO differed, with consolidation durvalumab only recommended in those patients who expressed PD-L1(i.e.,>1%), they noted.

“Currently, in Australia, there is no consensus practice guideline on how to manage these patients, undoubtedly leading to differing clinical approaches,” the authors added.

“The majority of specialised thoracic oncology centres are located in central metropolitan areas, but many patients with stage III disease are treated regionally and rurally. This undoubtedly would also influence practice, given the differing access to subsidised services for patients.”

Interestingly,18%,10%, and 10% of prescribers discussed self-funded oral tyrosine kinase inhibitor (TKI) therapy inpatients with EGFR, ALK, or ROS-1 mutated NSCLC respectively as a substitute for consolidation durvalumab.

This was despite any current evidence to support consolidation TKI use in this setting, although results from at least one study were pending, the authors said.

“For those with PD-L1-negative disease, real-world data has also alluded to a PFS of less than 12 months,” they added.

“Our survey demonstrates that almost 70% of prescribers strongly advocate for durvalumab in this cohort, potentially reflecting a lack of definitive data to guide best prescribing practices.”

They concluded that given the complex management of unresectable stage III NSCLC, all cases should be discussed in an MDT setting.

“Additionally, clinicians should be routinely testing pathology samples for oncogenic driver mutations and PD-L1 expression as these appear to influence decision-making and guideline-based recommendations,” they wrote.

“Ideally, local practice guidelines are required to ensure consistency in prescribing patterns across Australia.”

“This is particularly important for low-volume and regional/rural oncologists who often are responsible for treating a wide range of tumour streams and may not be aware of new developments in sub-populations that could significantly influence treatment decisions.”