[Clinical Pharmacology Research for Promoting Individualized Cancer Chemotherapy]

Cancer chemotherapy has progressed remarkably with conventional and molecular-targeted anticancer drugs as well as immune checkpoint inhibitors. However, adverse drug reaction (ADR) management remains a challenge in cancer chemotherapy. Therefore, improving the quality of medical care through clinical pharmacology research is warranted. Intravenous injection of bendamustine in patients with follicular or mantle cell lymphoma frequently causes venous irritation. Because the underlying mechanisms are not clear, we investigated the factors responsible for bendamustine-induced venous irritation. Based on the results of our analysis, we altered the administration regimen and observed that the incidence of venous irritation, which manifested in a concentration-dependent manner following conventional approaches, significantly decreased when following the modified regimen. Guidelines on the management of chemotherapy-induced nausea and vomiting recommend aprepitant, a selective neurokinin-1 (NK-1) receptor antagonist, 5-hydroxytryptamine 3 (5-HT₃) receptor antagonists, and dexamethasone as prophylactic antiemetics. Pretreatment with high-dose chemotherapy before hematopoietic stem cell transplantation has extremely high emetogenic potential. This can be countered by using aprepitant in combination with conventional antiemetics. However, the safety and efficacy of such combinations are unexplored. Upon evaluation, we observed improved antiemetic effects without an increase in ADRs. At this symposium, I highlight the significance of clinical pharmacology research for promoting individualized cancer chemotherapy.

Effect of aprepitant administration on CINV caused by cisplatin multi-day chemotherapy and pharmacokinetics of docetaxel

PURPOSE

To compare efficacy and safety of postponing administration of aprepitant and routine triple-antiemetic treatment for chemotherapy-induced nausea and vomiting in patients who received docetaxel and cisplatin multi-day chemotherapy treatment, and to evaluate the effect of aprepitant on docetaxel pharmacokinetics in the Chinese population.

METHODS

A total of 24 cancer patients (including 5 females and 19 males, 22-74 years old) received two cycles of high-emetic DP (docetaxel 75 mg/m² on day 1 + cisplatin 25 mg/m² on days 1-3) regimen. A randomized, two-period and cross-over study was applied for prevention of chemotherapy-induced nausea and vomiting. The patients in group A took aprepitant 125 mg on day 1 and 80 mg on days 2-3 (administered aprepitant 1 h before chemotherapy). In group B, the patients took aprepitant 125 mg on day 2, 80 mg on days 3-4, which was delayed 1 day than group A. Efficacy and safety in overall phase were evaluated within 5 days after initiation of chemotherapy. Simultaneously, the differences in the pharmacokinetic parameters of docetaxel between two different antiemetic treatments are compared.

RESULTS

The CR rate of delayed-phase nausea was compared between the routine triple-antiemetic treatment (group A) and the aprepitant delayed 1-day administration treatment (group B), and the difference was statistically significant (16.7% vs 45.8% P < 0.05), despite there were similar for two groups in the CR rate of acute-phase nausea and vomiting, and delayed-phase vomiting. In two groups, the area under the docetaxel curve (AUC_0-t values) (mean ± SD) of docetaxel was 1134.21 ± 732.55 (ng h/mL) and 1080.94 ± 585.09 (ng h/mL), and the geometric means were 944.82 and 902.10 (ng h/mL), respectively. There was no significant difference in AUC values between the two antiemetic treatments (P > 0.05), as well as C_max, CL_z, T_1/2z, MRT and T_max.

CONCLUSIONS

Delayed administration of aprepitant provided superior delayed-phase nausea protection for patients who received cisplatin-based chemotherapy in comparison with the routine triple-antiemetic treatment. In addition, in the routine triple-antiemetic treatment, aprepitant did not significantly affect the main pharmacokinetic parameters of docetaxel.

Effect of increase in duration of aprepitant consumption from 3 to 6 days on the prevention of nausea and vomiting in women receiving combination of anthracycline/cyclophosphamide chemotherapy: A randomized, crossover, clinical trial

BACKGROUND

Aprepitant is one of the effective antiemetic drugs that usually used for a period of 3 days for prevention of anthracycline/cyclophosphamide (AC) induced nausea and vomiting. However, many patients still experience nausea and vomiting on days 3-5. The aim of this study was to evaluate the effect of an increase in duration of aprepitant consumption from 3 to 6 days on the prevention of nausea and vomiting in women receiving AC chemotherapy.

MATERIALS AND METHODS

It was a randomized, crossover, controlled clinical trial. Women with breast cancer and scheduled to receive AC regimens were enrolled in this study. Enrolled patients were randomized into two groups. Group I received 3 days regimen of aprepitant in the first course of AC regimen chemotherapy and 6 days regimen of aprepitant in the second course; Group II received 6 days regimen followed by 3 days regimen. For nausea and vomiting assessment, we used Eastern Cooperative Oncology Group questionnaire.

RESULTS

Forty-nine patients were enrolled in this study. Sixty-three percent achieved a complete response with 6 days aprepitant regimen compared with 39% with 3 days regimen (P < 0.001). Ten percent had at least one vomiting episode during the 6 days regimen versus 15% with 3 days regimen (P = 0.034). Nausea was significantly more severe in 3 days regimen of aprepitant than in 6 days regimen.

CONCLUSION

Increase in the duration of aprepitant consumption through 6 days resulted in significantly better prevention of nausea and vomiting than 3 days consumption for women receiving AC chemotherapy.

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.

Current advances in treatment of gastroparesis

INTRODUCTION

Gastroparesis is a syndrome defined by delayed gastric emptying in the absence of mechanical obstruction. Gastroparesis has significant symptomatology and negative impacts on the patient's quality of life.

AREAS COVERED

This article reviews current treatment options for gastroparesis, recent advances in treatment and future directions that treatment may head. Current options are broadly divided into prokinetics and symptom modulators. Within each group, current modalities as well as recent advances are discussed according to agent mechanism of action. Lastly, findings regarding the cellular pathophysiology involved in gastroparesis will be briefly reviewed along with their implications for future treatments.

EXPERT OPINION

The numerous motor functions and neural inputs that control gastric motility are complex and not fully understood. Our lack of understanding of its pathophysiology has led to treatment options which are empirical, palliative and often ineffective. Newly intensified interest in the cellular pathophysiology behind gastroparesis provides promise for a new era of treatments. Identification of common cellular changes in gastroparesis has provided targets for treatment that may allow us to one day better treat the symptoms of gastroparesis related to its underlying pathophysiology. This is the future of gastroparesis therapy.

Phase II, open label, randomized comparative trial of ondansetron alone versus the combination of ondansetron and aprepitant for the prevention of nausea and vomiting in patients with hematologic malignancies receiving regimens containing high-dose cytarabine

Background. Aprepitant is a P/neurokinin-1 receptor antagonist approved for the prevention of CINV in moderate emetic risk chemotherapy. We explored its effectiveness in patients with leukemia receiving cytarabine-based chemotherapy. Methods. Patients were randomized to ondansetron (OND) 8 mg IV 30 minutes before cytarabine followed by 24 mg IV continuous infusion daily until 6-12 hours after the last dose of chemotherapy alone or with aprepitant (APREP) oral 125 mg 6-12 hrs before chemotherapy and 80 mg daily until 1 day after the last dose of chemotherapy. Results. Forty-nine patients were enrolled in each arm; 42 in OND and 41 in OND + APREP arm were evaluable for efficacy. The ORR with OND + APREP was 80% compared to 67% with OND alone (P = 0.11). On days 6 and 7, higher proportion of patients treated with OND + APREP were free from nausea (74%, 74% versus 68%, 67%; P = 0.27 and 0.18, resp.). Requirement of rescue medications on days 2 and 3 was fewer in OND + APREP arm 7% and 5% compared to 21% and 16% in the OND arm, respectively (P = 0.06 and P = 0.07). Conclusions. There was a trend for overall improvement in emesis with ondansetron plus aprepitant. The potential benefit of this approach with specific chemotherapy combinations remains to be determined.

Efficacy and safety of aprepitant in allogeneic hematopoietic stem cell transplantation

Study Objective

To evaluate the efficacy and safety of aprepitant added to standard antiemetic regimens used in high-dose chemotherapy for allogeneic hematopoietic stem cell transplantation (allo-HSCT).

Design

Retrospective medical record review.

Setting

Hematology ward of a university hospital in Japan.

Patients

Of 88 patients treated with high-dose chemotherapy followed by allo-HSCT, 46 received aprepitant and granisetron as antiemetic therapy (between April 1, 2010, and December 31, 2011), and 42 received granisetron alone (between April 1, 2008, and March 31, 2010).

Interventions

Patients in both groups received 3 mg of granisetron intravenously 30 minutes before the administration of anticancer drugs. In the aprepitant group, 125 mg of aprepitant was administered orally 60–90 minutes before the administration of the first moderately to highly emetogenic anticancer drug. On the following days, 80 mg of aprepitant was administered orally every morning. The mean administration duration of aprepitant was 3.3 days (range 3–6 days).

Measurements and Main Results

The primary objective was to evaluate the percentage of patients who achieved complete response (CR; no vomiting and none to mild nausea). The CR rate in the aprepitant group was significantly higher than that in the control group (48% vs 24%, p=0.02). Multivariate analysis showed that nonprophylactic use of aprepitant was associated with failure to achieve CR (odds ratio [OR] 2.92; 95% confidence interval [CI] 1.13–7.99, p=0.03). The frequency of abdominal pain was lower in the aprepitant group (9% vs 25%, p=0.03). Rates of other frequently observed adverse drug events were similar between groups. There was no significant difference in neutrophil engraftment (median 18 vs 17 days), platelet engraftment (median 32 vs 32 days), the incidence of acute graft-versus-host-disease (63% vs 55%, p=0.52), viral infection (74% vs 67%, p=0.49), or 1-year overall survival (63% vs 62%, p=0.90) between the two groups.

Conclusions

The addition of aprepitant to granisetron increases the antiemetic effect without influencing transplantation-related toxicities in allo-HSCT.