The role of second-generation 5-HT3 receptor antagonists in managing chemotherapy-induced nausea and vomiting in hematological malignancies

Portuguese consensus on the prevention and treatment of nausea and vomiting induced by cancer treatments

Chemotherapy-induced nausea and vomiting (CINV) and radiotherapy-induced nausea and vomiting (RINV) strongly affect the quality of life of patients with cancer. Inadequate antiemetic control leads to the decline of patients' quality of life, increases rescue interventions, and may even compromise adherence to cancer treatment. Although there are international recommendations for controlling CINV and RINV, these recommendations focus mainly on pharmacological management, with scarce information on additional measures that patients may adopt. Moreover, the prophylaxis and management of CINV/RINV are not always applied. Thus, we identified the need to systematize the strategies for preventing and managing CINV/RINV and the associated risk factors to implement and promote effective prophylactic antiemetic regimens therapy in patients with cancer. This review sought to create a set of practical recommendations for managing and controlling CINV/RINV, according to the current international recommendations for antiemetic therapy and the main risk factors. Conclusively, we intended to produce a patient-centered guidance document for health care professionals focused on the awareness, monitoring, and treatment of CINV/RINV.

Every-other-day palonosetron plus aprepitant for prevention of emesis following induction chemotherapy for acute myeloid leukemia: A randomized, controlled study from the "Rete Ematologica Pugliese"

BACKGROUND

Compared with older 5-HT₃ receptor antagonists, palonosetron requires fewer drug administrations to prevent chemotherapy-induced nausea and vomiting (CINV) following multiple-day chemotherapy. We conducted a phase II multicenter study comparing palonosetron plus aprepitant to palonosetron alone in patients undergoing a range of induction chemotherapy regimens for acute myeloid leukemia (AML).

METHODS

Patients were randomized to palonosetron (0.25 mg) every other day until the last dose of chemotherapy alone or with aprepitant on days 1-3. Patients mainly received an anthracycline on days 1-3 plus cytarabine administered for 5-10 days. The primary end point was complete response (CR; no emesis and no rescue medication) over the whole study period (days of chemotherapy plus two additional days). Unplanned analysis of time to anti-emetic treatment failure (TTF) was also performed.

RESULTS

Of the 134 patients enrolled in the study, 130 were evaluable: 68 subjects received palonosetron plus aprepitant and 62 received palonosetron alone. Although the primary end point of CR was similar between the treatment arms (72% vs 69%; P = .55), a higher proportion of patients treated with palonosetron plus aprepitant were free from nausea during the whole study period (43% vs 27%; P = .03). There was also a significant difference in favor of the two-drug regimens in TTF (median: 5 days vs 3 days; P = .03).

CONCLUSIONS

The study suggests that every-other-day palonosetron plus 3-day aprepitant can add clinical benefit to the control of CINV caused by multiple-day, corticosteroid-free chemotherapy for AML. In this challenging setting of CINV, further investigations of palonosetron in combination with aprepitant administered with an expanded schedule are warranted. ClinicalTrial.gov identifier: NCT02205164.

Delayed chemotherapy-induced nausea and vomiting in autologous hematopoietic cell transplant patients: an exploratory analysis

PURPOSE

Delayed chemotherapy-induced nausea and vomiting (CINV) continues to be a problem in patients undergoing a hematopoietic cell transplant (HCT) despite progress in antiemetic prophylaxis. This study investigated the clinical course of nausea and vomiting (NV) and retching over the 5 days following an autologous HCT in a transplant setting.

METHODS

This longitudinal observational study was an exploratory analysis of data from a trial that assessed the efficacy of aroma in preventing NV related to dimethyl sulfoxide in 69 autologous HCT patients undergoing highly emetogenic chemotherapy (HEC; n = 56) or moderately emetogenic chemotherapy (MEC; n = 13).

RESULTS

Nausea started to increase on the second day after reinfusion, with a peak between 72 and 96 hours, and decreased on the fifth day. The pattern for vomiting was similar, while retching episodes remained unchanged after the third day following transplant. Nausea and emesis were observed in 73% (n = 41) and 64% (n = 36) of HEC patients, respectively, and in 85% (n = 11) and 62% (n = 8) of MEC patients, respectively.

CONCLUSIONS

Uncontrolled delayed CINV is still a challenge for autologous HCT patients. Nausea, vomiting and retching are 3 different symptoms that should be assessed and managed separately in routine clinical practice.

Evaluation of an every-other-day palonosetron schedule to control emesis in multiple-day high-dose chemotherapy

AIM

Efficacy of intermittent palonosetron dosing in patients undergoing multiple-day, high-dose chemotherapy (HDC) was investigated.

PATIENTS & METHODS

Fifty-eight patients received palonosetron (0.25 mg intravenous [iv.]) every other day plus daily dexamethasone (8 mg iv. twice daily) dosing. The primary end point was complete control (CC; no emesis, no rescue anti-emetics, and no more than mild nausea) in the overall acute-period (until 24 h after chemotherapy completion).

RESULTS

Acute-period CC occurred in 81% and 50% of patients receiving palonosetron and ondansetron (historical control cohort), respectively. Palonosetron (odds ratio [OR]: 4.37; p = 0.001) and a longer duration of HDC regimen (OR: 3.47; p = 0.011) independently predicted a better anti-emetic outcome.

CONCLUSION

Palonosetron every other day plus daily dexamethasone is an effective anti-emetic coverage in patients undergoing HDC.

Prolonged inhibition of 5-HT₃ receptors by palonosetron results from surface receptor inhibition rather than inducing receptor internalization

BACKGROUND AND PURPOSE

The 5-HT₃ receptor antagonist palonosetron is an important treatment for emesis and nausea during cancer therapy. Its clinical efficacy may result from its unique binding and clearance characteristics and receptor down-regulation mechanisms. We investigated the mechanisms by which palonosetron exerts its long-term inhibition of 5-HT₃ receptors for a better understanding of its clinical efficacy.

EXPERIMENTAL APPROACH

Cell surface receptors (recombinantly expressed 5HT₃A or 5HT₃AB in COS-7 cells) were monitored using [³H]granisetron binding and ELISA after exposure to palonosetron. Receptor endocytosis was investigated using immunofluorescence microscopy.

KEY RESULTS

Chronic exposure to palonosetron reduced the number of available cell surface [³H]granisetron binding sites. This down-regulation was not sensitive to either low temperature or pharmacological inhibitors of endocytosis (dynasore or nystatin) suggesting that internalization did not play a role. This was corroborated by our observation that there was no change in cell surface 5-HT₃ receptor levels or increase in endocytic rate. Palonosetron exhibited slow dissociation from the receptor over many hours, with a significant proportion of binding sites being occupied for at least 4 days. Furthermore, our observations suggest that chronic receptor down-regulation involved interactions with an allosteric binding site.

CONCLUSIONS AND IMPLICATIONS

Palonosetron acts as a pseudo-irreversible antagonist causing prolonged inhibition of 5-HT₃ receptors due to its very slow dissociation. In addition, an irreversible binding mode persists for at least 4 days. Allosteric receptor interactions appear to play a role in this phenomenon.