medwireNews: Patients with chemotherapy-refractory small-cell lung cancer (SCLC) may benefit from treatment with the topoisomerase II inhibitor amrubicin, research from Japan suggests.
The 82 patients enrolled in the open-label, single-arm Japan Clinical Oncology Group Study JCOG0901 trial received amrubicin 40 mg/m2 for 3 days on a 21-day cycle, for a median of four cycles. All patients had already experienced no response, or progression, following treatment with at least one platinum-based regimen, with 51.2% previously treated with etoposide and 57.3% with irinotecan.
The overall response rate, defined as an independently assessed complete or partial response, was highly significant, at 32.9%, compared with a null hypothesis threshold of 10.0% or below. Median progression-free survival was 3.5 months and overall survival was 8.9 months, with over a third (35.7%) of patients alive 1 year later.
And amrubicin showed particular promise for patients who had not previously received etoposide, another type of topoisomere II inhibitor, say Haruyasu Murakami (Shizuoka Cancer Center) and colleagues.
Etoposide-naïve patients achieved an objective response rate of 45.0%, compared with 21.4% for those previously treated with the agent, a significant difference.
Both median progression-free survival and overall survival were also significantly higher in etoposide-naïve than pretreated patients, at 5.1 versus 2.9 months and 13.1 versus 7.9 months, respectively.
The reduced benefit of amrubicin found in patients previously treated with etoposide may be due to downregulation of topoisomerase II following the initial treatment, Murakami et al suggest in Lung Cancer.
Haematological toxicities were common, with 93.9% of patients developing grade 3 or 4 neutropaenia, 85.4% leukopaenia, 25.6% anaemia and 26.8% developing febrile neutropaenia.
But there was no evidence of cardiotoxicity associated with amrubicin treatment and other nonhaematological side effects were mild.
“On the basis of these results, we conclude that [amrubicin] monotherapy is suitable as an effective and safe treatment option for refractory SCLC”, the team concludes.
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By Lynda Williams, Senior medwireNews Reporter