Important developments addressed by current international guidelines are summarised below:rrr
1. Antiemetic efficacy of olanzapine
- ASCO, NCCN and MASCC/ESMO now include olanzapine in their guidelines.rrr ASCO and MASCC/ESMO recommend use with high emetic risk anti-cancer drugs, and NCCN for high emetic risk (preferred option) and moderate emetic risk anti-cancer drugs. Evidence has also confirmed that the use of olanzapine as a rescue for breakthrough emesis is superior to metoclopramide for patients receiving high emetic risk anti-cancer drugs.r
- Although the olanzapine dose used in studies has mainly been 10 mg, data suggests that a 5 mg dose is efficacious and reflects current clinical practice.r The 5 mg dose should be considered as the preferred starting dose, especially for elderly patients and for patients with concerns regarding excessive sedation.
- It is recommended that olanzapine is added to the antiemetic regimen for patients treated with high dose cytotoxic therapy and blood or marrow transplantation.
eviQ acknowledges there is a mismatch between the Australian indication for olanzapine and international guideline recommendations. The clinical data supporting olanzapine in the management of AINV was not explored at the time of its initial TGA registration.* For this reason, olanzapine will not be included in the eviQ protocol treatment schedules, until registration recognises olanzapine has an established place in the management of AINV.
*via personal communication from initial sponsor September 2020
2. Dexamethasone use in breast anthracycline and cyclophosphamide (AC) regimens
ASCO and MASCC/ESMO no longer recommend the administration of dexamethasone on days 2 to 4 following AC anti-cancer therapy, whereas NCCN (which does not distinguish between AC vs. non-AC high emetic risk regimens) states that administration may be considered. This was based on limited data supporting dexamethasone beyond day 1 when an NK1 receptor antagonist (NK1 RA) is used with AC.rrr
eviQ breast AC protocols do not include dexamethasone for delayed emesis in the treatment schedule. Protocols include a note stating that dexamethasone may be required for those with risk factors for delayed nausea and vomiting.
3. Antiemetic prophylaxis in patients treated with immune checkpoint inhibitors
- The addition of an immune checkpoint inhibitor to anti-cancer therapy does not change the emetogenic classification or antiemetic regimen used.r
- All immune checkpoint inhibitors administered either alone or in combination with other immune checkpoint inhibitors are minimally emetogenic and do not require the use of a prophylactic antiemetic.
4. Low emetic risk anti-cancer drugs
The option of a single dose of a 5HT3 receptor antagonist (5HT3 RA) or a single dose of dexamethasone, for the prevention of acute nausea and vomiting associated with low emetic risk anti-cancer drugs is now included in all guidelines.rrr However, it is important to note that the quality of the evidence to support these recommendations is low, guided by expert opinion and informal consensus. Both NCCN and MASCC/ESMO include alternatives; MASCC/ESMO a dopamine receptor antagonist e.g. metoclopramide; and NCCN metoclopramide or prochlorperazine. There is no evidence at this time to recommend superiority of one option over another.
5. Changes to the display of emetogenic risk for oral anti-cancer drugs
As emetic risk information for oral anti-cancer drugs is limited and varies, eviQ has now aligned with ASCO, NCCN and MASCC/ESMO to display two categories of emetogenicity for oral anti-cancer drugs: minimal or low, and moderate or high.rrr