medwireNews: Low-dose olanzapine is noninferior to the standard dose for controlling chemotherapy-induced nausea and vomiting (CINV) in people with cancer receiving highly emetogenic chemotherapy, and results in significantly less daytime somnolence, show phase 3 trial data.
The investigators therefore say that olanzapine 2.5 mg/day alongside triple anti-emetic therapy “should be considered as a new standard of care.”
For the trial, Jyoti Bajpai and colleagues from the Tata Memorial Centre in Mumbai, India, recruited 267 patients with cancer who were scheduled to receive doxorubicin–cyclophosphamide or high-dose cisplatin at their center. Participants were aged a median of 45 years, and the large majority were women (94%) and had breast cancer (91%).
As reported in The Lancet Oncology, the primary endpoint of complete control – defined as no emetic episodes, no rescue medications, and no or mild nausea in the 120 hours following the first cycle of chemotherapy – was achieved by 45% of patients who received olanzapine 2.5 mg daily on days 1–4 of cycle 1 alongside standard triple anti-emetic therapy comprising a 5-HT3 receptor agonist, single-dose dexamethasone, and an NK-1 receptor agonist.
The rate of complete control was a comparable 44% among those who instead received olanzapine 10 mg/day, and the 95% confidence interval excluded the noninferiority margin of 10%.
Of note, the incidence of the secondary safety endpoint of any-grade daytime somnolence in the 120 hours after the first cycle of chemotherapy was significantly lower in the olanzapine 2.5 mg than 10.0 mg group, at 65% versus 90%.
A post-hoc analysis showed similar results for severe daytime somnolence on day 1, which was reported by 5% of patients in the olanzapine 2.5 mg arm and 40% of those in the olanzapine 10.0 mg arm.
And the researchers note: “The severity of daytime somnolence was highest on day 1 and, although it reduced on days 2–5 in both groups, its incidence was lower in the 2.5 mg olanzapine group than the 10.0 mg olanzapine group on all days.”
They draw attention to the limitations of the study, such as its single-center design, the predominance of women with breast cancer, and the use of a lower dose of steroids than standard, “which was potentially associated with fewer steroid-related side effects.”
But Bajpai and team nevertheless believe that “[t]his low-cost intervention is potentially practice-changing, with wide reach and applicability globally.”
They continue: “Future studies are required to define the chemotherapy-induced nausea and vomiting prevention efficacy of low-dose versus standard-dose steroids in combination with low-dose olanzapine.”
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