Clinical Pharmacology for Akynzeo
Mechanism Of Action
Netupitant is a selective antagonist of human substance P/neurokinin 1 (NK-1) receptors.
Palonosetron is a 5-HT3 receptor antagonist with a strong binding affinity for this receptor and little or no affinity for other receptors. Cancer chemotherapy may be associated with a high incidence of nausea and vomiting, particularly when certain agents, such as cisplatin, are used. 5HT3 receptors are located on the nerve terminals of the vagus in the periphery and centrally in the chemoreceptor trigger zone of the area postrema. Chemotherapeutic agents produce nausea and vomiting by stimulating the release of serotonin from the enterochromaffin cells of the small intestine. Serotonin then activates 5-HT3 receptors located on vagal afferents to initiate the vomiting reflex. The development of acute emesis is known to depend on serotonin and its 5-HT3 receptors have been demonstrated to selectively stimulate the emetic response.
Delayed emesis has been largely associated with the activation of tachykinin family neurokinin 1 (NK-1) receptors (broadly distributed in the central and peripheral nervous systems) by substance P. As shown in in vitro and in vivo studies, netupitant inhibits substance P mediated responses.
Pharmacodynamics
NK-1 Receptor Occupancy
The receptor occupancy of netupitant was measured in a human Positron Emission Tomography (PET) study. Netupitant was shown to cross the blood brain barrier with a NK-1 receptor occupancy of 92.5%, 86.5%, 85.0%, 78.0%, and 76.0% in striatum at 6, 24, 48, 72, and 96 hours, respectively, after oral administration of 300 mg netupitant.
Cardiac Electrophysiology
An AKYNZEO oral dose of 600 mg netupitant (2 times the recommended dose) and 1.5 mg palonosetron (3 times the recommended dose) did not prolong the QT interval to any clinically relevant extent.
The recommended dose of AKYNZEO for injection (235 mg fosnetupitant and 0.25 mg palonosetron) did not prolong the QT interval to any clinically relevant extent.
Pharmacokinetics
Netupitant And Palonosetron
Absorption
Upon single oral administration of AKYNZEO capsules to healthy subjects and patients, netupitant and palonosetron were measurable within 1 hour after administration and reached the maximum concentration (Cmax) in approximately 4 to 5 hours (Table 7).
Table 7: Systemic Exposure (AUCinf and Cmax) of Netupitant and Palonosetron After a Single Oral Dose of AKYNZEO in Healthy Subjects and Cancer Patients
| Parameter |
Population |
Mean ( CV%2) |
| Netupitant |
Palonosetron |
| AUCinf (ng•h/mL) |
Healthy Subjects |
14,402 (51) |
56.7 (33) |
| Patients |
17,365 (39) |
58.3 (50) |
| Cmax (ng/mL) |
Healthy Subjects |
434 (56) |
1.53 (25) |
| Patients |
496 (49) |
0.95 (35) |
| tmax (h)1 |
Healthy Subjects |
5 (2 to 12) |
5 (1 to 12) |
| Patients |
4 (2 to 8) |
5 (1 to 12) |
| 1 median (min-max); 2CV: coefficient of variation; AUCinf: area under the plasma concentration-time curve from time 0 to infinity; tmax: time to maximum concentration. |
Following oral administration, the absolute bioavailability of palonosetron was approximately 97%.
When AKYNZEO capsules were administered under fed conditions, the systemic exposure to netupitant and palonosetron was similar to the exposure under fasting conditions.
In cancer patients who received a single dose of AKYNZEO capsules 1 hour prior to chemotherapy (docetaxel, etoposide, or cyclophosphamide), the Cmax and the area under the concentration-time curve from time zero to infinity (AUCinf ) of netupitant and its metabolites were similar to those in healthy subjects. The mean Cmax and AUCinf of palonosetron in cancer patients were similar to those in healthy subjects.
No changes in pharmacokinetics of netupitant and palonosetron were observed when 450 mg oral netupitant and 0.75 mg oral palonosetron were given alone or co-administered (1.5 times the recommended dose of AKYNZEO capsules).
Dose Proportionality
Netupitant
There was a greater than dose-proportional increase in the systemic exposure (108-fold AUCinf increase for a 30-fold dose increase) when the oral netupitant dose was increased from 10 mg (approximately 3% the recommended dose in AKYNZEO capsules) to 300 mg of netupitant and a dose-proportional increase in the systemic exposure when the netupitant dose was increased from 300 mg to 450 mg of netupitant (1.5 times the recommended dose in AKYNZEO capsules).
Palonosetron
After single oral doses of palonosetron ranging from 0.25 to 6.8 mg (0.5 to 13.6 times the recommended dose in AKYNZEO capsules) using a buffered solution, the mean Cmax and AUCinf were dose proportional in healthy subjects.
Following single intravenous doses of AKYNZEO for injection in patients or fosnetupitant in healthy subjects, Cmax of netupitant and palonosetron were achieved at the end of the 30-minute infusion (Table 8).
Table 8: Systemic Exposure (AUC0-120 and Cmax) of Netupitant and Palonosetron After a Single Intravenous Dose of AKYNZEO for Injection in Cancer Patients or a Single Intravenous Dose of Fosnetupitant in Healthy Subjects
| Parameter |
Population |
Mean (CV%2) |
| Netupitant |
Palonosetron |
| AUC0-120 (ng•h/mL) |
Healthy Subjects |
12,012 (19) |
-- |
| Patients |
8,922 (22) |
28 (28) |
| Cmax (ng/mL) |
Healthy Subjects |
841 (21) |
-- |
| Patients |
590 (28) |
0.8 (35) |
| tmax (h)1 |
Healthy Subjects |
0.5 (0.5 to 0.4) |
-- |
| Patients |
0.6 (0.5 to 4) |
0.6 (0.5 to 6) |
| 1 median (min-max); 2CV: coefficient of variation; AUC0-120: AUC from time 0 to 120 hours from start of infusion |
Distribution
After single oral administration of AKYNZEO capsules, netupitant and palonosetron were widely distributed throughout the body (Table 9).
Table 9: Volume of Distribution (Vz/F) in Healthy Subjects and Cancer Patients After a Single Oral Dose of AKYNZEO and In Vitro Protein Binding
| Parameter |
Population |
Mean (CV%c) |
| Netupitant |
Palonosetron |
| Vz/F (L) |
Healthy Subjects |
3314 (53) |
586 (33) |
| Patients |
1982 (46) |
663 (24) |
| Plasma Protein Binding |
In vitro studies |
Netupitant: > 99.5%a Major Metabolites: > 97%b |
62% |
| a Concentration range: 10 to 1300 ng/mL; b Concentration range: 100 to 200 ng/mL; cCV: coefficient of variation |
After administration of single dose of AKYNZEO for injection in patients, the mean ± SD of volume of distribution (Vz) of netupitant and palonosetron were 2627 ± 990 L and 594 ± 239 L, respectively, consistent with previous estimates after single oral administration of AKYNZEO capsules in healthy subjects and cancer patients (Table 9).
Elimination – Netupitant
After a single dose of AKYNZEO capsules, netupitant is eliminated from the body in a multi-exponential fashion and the mean ± SD of apparent elimination half-life was of 96 ± 59 hours in healthy subjects and 80 ± 29 hours in cancer patients. The mean ± SD of estimated systemic clearance (CL/F) was 26.3 ± 12.5 L/h in healthy subjects and 20.3 ± 9.2 L/h in patients.
In patients, following intravenous infusion of AKYNZEO for injection, the mean ± SD total body clearance (CL) and terminal half-life (t½) of netupitant were 14.1 ± 5.3 L/h and 144 ± 73 hours, respectively.
Metabolism
Once absorbed, netupitant is extensively metabolized to form three major metabolites: desmethyl derivative, M1; N-oxide derivative, m²; and OH-methyl derivative, M3. Metabolism is mediated primarily by CYP3A4 and to a lesser extent by CYP2C9 and CYP2D6. Metabolites M1, m² and M3 were shown to bind to the substance P/neurokinin 1 (NK-1) receptor.
The mean AUCinf for metabolites M1, M2 and M3 was 29%, 14% and 33% of netupitant, respectively. The median tmax for metabolite m² was 5 hours and was about 17 to 32 hours for metabolites M1 and M3, respectively.
Excretion
After a single oral administration of [14C]-netupitant, approximately half the administered radioactivity was recovered from urine and feces within 120 hours of dosing. The total of 3.95% and 70.7% of the radioactive dose was recovered in the urine and feces collected over 336 hours, respectively, and the mean fraction of an oral dose of netupitant excreted unchanged in urine is less than 1% suggesting renal clearance is not a significant elimination route for the netupitantrelated entities. About 86.5% and 4.7% of administered radioactivity was estimated to be excreted via the feces and urine within 30 days post-dose.
Elimination -Palonosetron
Following oral administration of AKYNZEO capsules in healthy subjects and cancer patients, the mean ( ± SD) of half-life of palonosetron was 44 ± 15 hours and 50 ± 16 hours, respectively, whereas the mean ± SD of total body clearance (CL/F) was 9.6 ± 2.7 L/h and 10.0 ± 3.4 L/h, respectively.
After a single intravenous palonosetron dose of 10 mcg/kg (approximately 3 times the recommended dose in AKYNZEO for injection), the mean ± SD of total body clearance (CL) of palonosetron in healthy subjects was 12.1 ± 3.7 L/h, and renal clearance (CLR) was 5.1 ± 2.1 L/h.
In patients, following intravenous infusion of AKYNZEO for injection, the mean ± SD total body clearance (CL) and terminal half-life (t½) of palonosetron were 7.6 ± 2.6 L/h and 58 ± 27 h, respectively.
Metabolism
Palonosetron is eliminated by multiple routes with approximately 50% metabolized to form two primary metabolites: N-oxide-palonosetron and 6-S-hydroxy-palonosetron. These metabolites each have less than 1% of the 5-HT3 receptor antagonist activity of palonosetron. In vitro metabolism studies have suggested that CYP2D6 and to a lesser extent CYP3A4 and CYP1A2 are involved in the metabolism of palonosetron. However, clinical pharmacokinetic parameters such as Cmax, AUCinf, CL, CLR, Vz and t½ are not significantly different between poor and extensive metabolizers of CYP2D6 substrates.
Excretion
Following administration of a single oral 0.75 mg dose of [14C]-palonosetron (1.5 times the recommended dose in AZKYNZEO capsules) to six healthy subjects, 85% to 93% of the total radioactivity was excreted in urine, and 5% to 8% was eliminated in feces. The amount of unchanged palonosetron excreted in the urine represented approximately 40% of the administered dose.
Fosnetupitant
Absorption
Following single intravenous doses of AKYNZEO for injection in patients (235 mg fosnetupitant and 0.25 mg palonosetron infused in 30 minutes) or fosnetupitant in healthy subjects (235 mg fosnetupitant infused in 30 minutes), maximum concentrations of fosnetupitant were achieved at the end of the 30-minute infusion (Table 10).
Table 10: Systemic Exposure of Fosnetupitant After a Single Intravenous Dose of Fosnetupitant in Healthy Subjects or AKYNZEO for Injection in Cancer Patients
| Parameter |
Population |
Mean (CV%2) |
| Cmax (ng/mL) |
Healthy Subjects |
6431 (14) |
| Patients |
3478 (45) |
| tmax1 (h) |
Healthy Subjects |
0.5 (0.25 to 0.5) |
| Patients |
0.5 (0.5 to 0.6) |
| AUCinf (ng•h/mL) |
Healthy Subjects |
2938 (12) |
| Patients |
1401 (46) |
| 1 median (min-max); 2CV: coefficient of variation; AUCinf: AUC from time 0 to infinity |
In cross-study comparisons, the mean Cmax and AUCinf of fosnetupitant were lower in patients than in healthy subjects. Similarly, AUC0-120 and Cmax of netupitant in patients were 26% and 30% lower than in healthy subjects, respectively (Table 8). The differences in systemic exposures to netupitant are clinically insignificant.
In healthy subjects, there was a dose-proportional increase in the systemic exposure when the dose of fosnetupitant was increased from 17.6 mg (7.5% of recommended dose in AKYNZEO for injection) to 353 mg (150% of recommended dose in AKYNZEO for injection and AKYNZEO injection).
Distribution
The mean ± SD volume of distribution (Vz) of fosnetupitant in healthy subjects and in patients was 124 ± 76 L and 296 ±535 L, respectively. The human plasma protein binding of fosnetupitant was 92% at 1 micromolar and 95% at 10 micromolar.
Elimination
After intravenous administration of AKYNZEO for injection, fosnetupitant plasma concentrations declined in a biexponential manner. Thirty minutes after the end of the infusion, the mean plasma concentration of fosnetupitant was less than 1% of Cmax.
The mean ± SD of terminal elimination half-life and systemic plasma clearance (CL) of fosnetupitant were respectively 0.75 ± 0.40 hours and 249 ± 270 L/h in cancer patients after a single IV dose of AKYNZEO. They were 0.96 ± 0.55 hours (mean ± SD) and 90 ± 13 L/h in healthy subjects after a single intravenous dose of fosnetupitant.
Metabolism
Fosnetupitant is converted in vivo to netupitant by metabolic hydrolysis. In patients receiving AKYNZEO intravenously, netupitant exposure was 17-fold fosnetupitant exposure, as determined by their AUCinf ratio. Netupitant metabolites M1, M2 and M3 were generated from the released netupitant. In patients, metabolite M1, M2 and M3 exposures were 32%, 21% and 28% of netupitant exposure. The median tmax for M1, M2, and M3 were 12, 2 and 12 hours, respectively.
Specific Populations
Geriatric Patients
In cancer patients receiving AKYNZEO capsules, population pharmacokinetic analysis indicated that age (within the range of 29 to 75 years) did not influence the pharmacokinetics of netupitant or palonosetron. In healthy elderly subjects (greater than 65 years of age) the mean AUCinf and Cmax was 25% and 36% higher, respectively, for netupitant, and 37% and 10% higher, respectively, for palonosetron compared to those in healthy younger adults (22 to 45 years of age). The increase in the systemic exposure to netupitant in the elderly subjects is not considered to be clinically significant.
Male And Female Patients
In a pooled analysis of data following AKYNZEO capsules, the Cmax for netupitant was 35% higher in females than in males while the AUCinf was similar between males and females. In female subjects, the mean AUCinf for palonosetron was 35% higher and the mean Cmax was 26% higher than in male subjects. Sex did not affect the pharmacokinetics of fosnetupitant, netupitant, netupitant metabolites and palonosetron after a single intravenous dose of AKYNZEO in patients. In healthy subjects, no effect of sex was observed on the pharmacokinetics of fosnetupitant, netupitant and its metabolites after a single intravenous dose of fosnetupitant alone. The mean ± SD of netupitant AUCinf and Cmax in patients were 15672 ± 5496 ng•h/mL and 567 ± 174 ng/mL, respectively in males and 15518 ± 4814 ng•h/mL and 609 ± 161 ng/mL, respectively in females.
Patients With Renal Impairment
Population pharmacokinetic analysis showed that mild and moderate renal impairment (creatinine clearance 30 to 60 mL/min) did not significantly affect the pharmacokinetics of netupitant in cancer patients. Netupitant has not been studied in patients with severe renal impairment (creatinine clearance less than 30 mL/min).
Mild to moderate renal impairment does not significantly affect palonosetron pharmacokinetic parameters. In a study with intravenous palonosetron, total systemic exposure to palonosetron increased by approximately 28% in patients with severe renal impairment relative to healthy subjects.
The pharmacokinetics of palonosetron and netupitant have not been studied in subjects with end-stage renal disease (creatinine clearance < 15 mL/min not on dialysis) [see Use In Specific Populations].
Patients With Hepatic Impairment
The effects of hepatic impairment on the pharmacokinetics of netupitant and palonosetron were studied following administration of a single oral dose of AKYNZEO to patients with mild (Child-Pugh score 5 to 6), moderate (Child-Pugh score 7 to 9), or severe (Child-Pugh score >9) hepatic impairment.
In patients with mild or moderate hepatic impairment, the mean AUCinf of netupitant was 67% and 86% higher, respectively, than in healthy subjects and the mean Cmax for netupitant was about 40% and 41% higher, respectively, than in healthy subjects.
In patients with mild or moderate hepatic impairment, the mean AUCinf of palonosetron was 33% and 62% higher, respectively, than in healthy subjects and the mean Cmax for palonosetron was about 14% higher and unchanged, respectively, than in healthy subjects.
The pharmacokinetics of netupitant and palonosetron were available from only two patients with severe hepatic impairment. As such the data are too limited to draw a conclusion [see Use In Specific Populations].
Drug Interaction Studies
Effect Of Netupitant/Fosnetupitant And/Or Palonosetron On Other Drugs
CYP3A4
In vitro studies have shown that netupitant and its metabolite M1 are inhibitors of CYP3A4. An in vivo study has confirmed that netupitant is a moderate inhibitor of CYP3A4.
Dexamethasone
In healthy subjects, the oral administration of a single AKYNZEO capsule with the CYP3A4 substrate dexamethasone (12 mg on day 1 followed by once-a-day administrations of 8 mg on days 2, 3, 4, 6, 8 and 10), increased the plasma concentrations of dexamethasone for 6 days (Table 11).
Table 11: Effect of a Single Dose of Oral AKYNZEO (Day 1) on the Systemic Exposure of a Co-administered CYP3A4 Substrate (Dexamethasone) in Healthy Subjects
| % Change for Dexamethasone |
| Day 1 |
Day 4 |
Day 6 |
Day 8 |
| Cmax |
AUC0-t |
Cmax |
AUC0-t |
Cmax |
AUC0-t |
Cmax |
AUC0-t |
| 2%↓ |
58%↑ |
54%↑ |
139%↑ |
29%↑ |
49%↑ |
7%↑ |
20%↑ |
| *the interacting drug (dexamethasone 12 mg) was administered on day 1 with AKYNZEO and alone (8 mg) on days 2, 3, 4, 6, 8 and 10; AUC0-t: AUC from time zero to time t of last measurable concentration after dexamethasone administration on Days 1, 4, 6 and 8 ↑ = Increased; ↓ = Decreased |
In healthy subjects, co-administration of a single intravenous fosnetupitant dose (235 mg) with a 20 mg oral dexamethasone on day 1 followed by twice-a-day administrations of 8 mg dexamethasone on days 2, 3, and 4, increased dexamethasone exposure 2.4-fold on day 4 (Table 12).
Table 12: Effect of a Single 235 mg Dose of Intravenous Fosnetupitant (Day 1) on the Systemic Exposure of a Co-administered CYP3A4 Substrate (Dexamethasone) in Healthy Subjects
| % Change for Dexamethasone |
| Day 1 |
Day 4 |
| Cmax |
AUC0-24 |
Cmax |
AUC84-108 |
| 3%↓ |
50%↑ |
70%↑ |
142%↑ |
| *the interacting drug (dexamethasone 20 mg) was administered on day 1 with AKYNZEO and alone (8 mg bid) on Days 2,3,4; AUC0-24: AUC from time 0 to 24h after dexamethasone administration on Day 1; AUC84-108: AUC from time 84h to 108h after dexamethasone administration on Day 4 ↑ = Increased; ↓ = Decreased |
Considering the limited fosnetupitant exposure in human plasma and its conversion to netupitant within 30 minutes after completion of infusion, the effects are ascribed to netupitant [see DRUG INTERACTIONS].
Midazolam
When co-administered with netupitant 300 mg the mean Cmax and AUCinf of midazolam after single dose oral administration of 7.5 mg midazolam was 36% and 126% higher, respectively [see DRUG INTERACTIONS].
Chemotherapeutic Agents (docetaxel, etoposide, cyclophosphamide)
Systemic exposure to intravenously administered chemotherapeutic agents that are metabolized by CYP3A4 was higher when AKYNZEO capsules was co-administered in cancer patients than when palonosetron alone was co-administered (see Table 13).
Table 13: Effect of a Single Dose of Oral AKYNZEO on the Systemic Exposure of Co-administered Chemotherapy Agents Metabolized by CYP3A4 in Patients with Cancer
| Co-administered Chemotherapeutic Agenta |
Change in Systemic Exposures of Chemotherapeutic Agents when Co-administered with AKYNZEO Capsules Compared to Coadministration with Palonosetron |
| AUC0-tb |
Cmax |
| Docetaxel 75 to 100 mg/m² |
35%↑ |
49%↑ |
| Etoposide 35 to 100 mg/m² |
28%↑ |
10%↑ |
| Cyclophosphamide 500 to 1000 mg/m² |
20%↑ |
27%↑ |
| a Following a single oral dose of AKYNZEO compared to co-administered with palonosetron alone bAUC0-t: AUC from time zero to time t of last measurable concentration ↑ = Increased; ↓ = Decreased |
The mean AUCinf of palonosetron was about 65% higher when AKYNZEO capsules was co-administered with docetaxel than with etoposide or cyclophosphamide, while the mean AUCinf of netupitant was similar among groups that received docetaxel, etoposide, or cyclophosphamide [see DRUG INTERACTIONS].
Erythromycin
When 500 mg erythromycin was co-administered with netupitant 300 mg, the systemic exposure of erythromycin was highly variable and the mean Cmax and AUCinf of erythromycin were increased by 92% and 56%, respectively. The change in exposure is not clinically significant.
Oral Contraceptives
A single dose of AKYNZEO capsules, when given with a single oral dose of 60 mcg ethinyl estradiol and 300 mcg levonorgestrel, showed no effect on Cmax and increased the AUC0-t of levonorgestrel by 46%. The Cmax and AUC0-t of ethinyl estradiol increased by 5% and 16% respectively. The change in exposure is not clinically significant [see DRUG INTERACTIONS].
Other CYP P450 enzymes
Based on the in vitro studies, netupitant, and its metabolites are unlikely to have in vivo drug-drug interaction via inhibition of CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, and CYP2D6 at the clinical dose of oral AKYNZEO.
Netupitant and its metabolites, M1, m² and M3, are not inducers of CYP1A2, CYP2B6, CYP2C9, CYP2C19 and CYP3A4.
In in vitro studies, palonosetron did not inhibit CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2D6, CYP2E1 and CYP3A4/5 or induce CYP1A2, CYP2D6 or CYP3A4/5. CYP2C19 was not investigated.
Transporters – P-gp And BCRP
Based on in vitro studies, netupitant is an inhibitor of P-glycoprotein (P-gp) and breast cancer resistant protein (BCRP) transporters. In vitro studies indicated that fosnetupitant is an inhibitor of P-gp. However, an in vivo interaction between AKYNZEO for injection and P-gp substrates is considered unlikely.
In vitro, palonosetron was an inhibitor of MATE1, MATE2-K, OCT1, OCT2 and OAT3 transporters. An in vivo interaction between AKYNZEO capsules or injection and transporter substrates is considered unlikely.
Digoxin –P-gp Substrate
Co-administration of oral netupitant 450 mg (1.5 times the recommended dose in AKYNZEO capsules) did not significantly affect the systemic exposure (4% increase of AUC0-24 at steady state) and urinary excretion (2% increase) of oral digoxin, a substrate of P-gp, at steady-state. Concurrent administration of AKYNZEO capsules or AKYNZEO for injection with digoxin is not expected to affect the systemic exposure to digoxin.
Other Transporters
In vitro studies indicate that netupitant and its three major metabolites are unlikely to have in vivo drug-drug interactions with human efflux transporters BSEP, MRP2, and human uptake transporters OATP1B1, OATP1B3, OAT1, OAT3, OCT1, and OCT2 at the clinical dose of 300 mg.
In vitro studies indicated that fosnetupitant is an inhibitor of OATP1B1 and OATP1B3 transporters. However, an in vivo interaction between AKYNZEO for injection and OATP1B1, OATP1B3, and P-gp substrates is considered unlikely.
In vitro studies indicated that fosnetupitant is not an inhibitor of MATE2-K transporter.
Effects Of Other Drugs On Netupitant/Fosnetupitant And/Or Palonosetron
Based on in vitro studies, fosnetupitant is not a substrate of BCRP, BSEP, MDR1 and MATE1, MATE2-K, OAT1, OAT3, OATP2B1, OCT1 and OCT2.
Netupitant is not a substrate for P-gp. However, metabolite m² is a substrate for P-gp.
Netupitant and palonosetron are CYP3A4 substrates. Co-administration of strong CYP3A4 inhibitors, such as ketoconazole, or strong CYP3A4 inducers, such as rifampin, with a single oral administration of AKYNZEO capsules affects with clinical significance the exposure to netupitant but not to palonosetron (Table 14).
Table 14: Change in Systemic Exposure to Netupitant and Palonosetron When a Single Dose of AKYNZEO is Co-Administered with Either a CYP3A4 Inhibitor or a CYP3A4 Inducer in Healthy Subjects
| Co-administered Drug |
Netupitantb |
Palonosetronb |
| AUCinf |
Cmax |
AUCinf |
Cmax |
| Strong CYP3A4 Inhibitor |
| Ketoconazole 400 mg once daily for 12 days |
140%↑ |
25%↑ |
10%↑ |
15%↑ |
| Strong CYP3A4 Inducer |
| Rifampin 600 mg once daily for 17 days |
62% ↓ |
82% ↓ |
19% ↓ |
15% ↓ |
| a Following a single oral dose of AKYNZEO; b Geometric Mean AUCinf and Cmax; ↑ = Increased; ↓ = Decreased |
Clinical Studies
Study 1
In a multicenter, randomized, parallel, double-blind, controlled clinical trial of 694 patients, the efficacy and safety of a single dose of oral netupitant in combination with oral palonosetron was compared with a single oral dose of palonosetron in cancer patients receiving a chemotherapy regimen that included cisplatin (median dose of 75 mg/m²). The efficacy of AKYNZEO was assessed in 135 patients who received AKYNZEO capsules (300 mg netupitant and 0.5 mg palonosetron) and 136 patients who received oral palonosetron 0.5 mg.
Treatment regimens for the AKYNZEO and palonosetron arms are summarized in Table 15.
Table 15: Oral Antiemetic Treatment Regimen in Study 1
| Treatment Regimen |
Day 1 |
Days 2 to 4 |
| AKYNZEO |
AKYNZEO capsules: 300 mg netupitant/ 0.5 mg palonosetron Dexamethasone 12 mg |
Dexamethasone 8 mg once a day |
| Palonosetron |
Palonosetron 0.5 mg Dexamethasone 20 mg |
Dexamethasone 8 mg twice a day |
Of the 135 patients who received AKYNZEO, 43% were women, and all patients were White. The age ranged from 19 to 77 years, with a median age of 53 years.
During the study, 86% of the 135 treated patients in the AKYNZEO arm received a concomitant chemotherapeutic agent in addition to protocol-mandated cisplatin. The most common chemotherapeutic agents and the proportion of patients exposed were cyclophosphamide (34%), fluorouracil (24%), etoposide (21%), and doxorubicin (16%).
The key efficacy endpoints were complete response (CR) (defined as no emetic episode and no use of rescue medication) for the 25 to 120 hour interval (delayed phase), CR for the 0 to 24 hour interval (acute phase), and CR within 120 hours (overall phase) after the start of the chemotherapy administration.
A summary of the key results from this study is shown in Table 16.
Table 16: Proportion of Patients Responding by Treatment Group and Phase in Study 1
|
AKYNZEO Capsules 300 mg netupitant/ 0.5 mg palonosetron
N=135 % |
Palonosetron 0.5 mg
N=136 % |
p-value* |
| COMPLETE RESPONSE |
| Delayed Phase† |
90.4 |
80.1 |
0.032 |
| Acute Phase‡ |
98.5 |
89.7 |
0.002 |
| Overall Phase§ |
89.6 |
76.5 |
0.003 |
*Adjusted p-values for multiple comparisons using Cochran-Mantel-Haenszel test, stratified by gender.
†Delayed phase: 25 to 120 hours post-cisplatin treatment.
‡Acute phase: 0 to 24 hours post-cisplatin treatment.
§Overall: 0 to 120 hours post-cisplatin treatment. |
Study 2 (NCT01339260)
In a multicenter, randomized, parallel, double-blind, active controlled, superiority trial, the efficacy and safety of a single oral dose of AKYNZEO was compared with a single oral dose of palonosetron 0.5 mg in cancer patients scheduled to receive the first cycle of an anthracycline and cyclophosphamide (AC) regimen for the treatment of a solid malignant tumor (Study 2). All patients received a single oral dose of dexamethasone. Treatment regimens for the AKYNZEO and palonosetron arms are summarized in Table 17.
Table 17: Oral Antiemetic Treatment Regimen in Study 2
| Treatment Regimen |
Day 1 |
Days 2 to 3 |
| AKYNZEO |
AKYNZEO capsules: 300 mg netupitant/ 0.5 mg palonosetron Dexamethasone 12 mg |
No antiemetic treatment |
| Palonosetron |
Palonosetron 0.5 mg Dexamethasone 20 mg |
No antiemetic treatment |
After completion of cycle 1, patients had the option to participate in a multiple-cycle extension, receiving the same treatment as assigned in cycle 1. There was no pre-specified limit of the number of repeat consecutive cycles for any patient.
A total of 1455 patients were randomized to the AKYNZEO arm or palonosetron arm. A total of 1450 patients (AKYNZEO n=725; palonosetron n=725) received study medication: of these, 1438 patients (99%) completed cycle 1 and 1286 patients (88%) continued treatment in the multiple-cycle extension. A total of 907 patients (62%) completed the multiple-cycle extension up to a maximum of eight treatment cycles.
Of the 725 patients who received AKYNZEO, 711 (98%) were women; 79% were White, 14% Asian, 6% Hispanic, and <1% were Black or Other. Age ranged from 22 to 79 years, with a median age of 54 years. A total of 724 patients (99.9%) were treated with cyclophosphamide. All patients were additionally treated with either doxorubicin (68%) or epirubicin (32%).
During the first cycle, 32% of the 725 patients treated with AKYNZEO received a concomitant chemotherapeutic agent in addition to protocol-mandated regimens, with the most common chemotherapeutic being fluorouracil (28%) and docetaxel (3%).
The primary efficacy endpoint was the CR rate in the delayed phase, 25 to120 hours after the start of chemotherapy administration.
Major secondary efficacy endpoints included CR for the acute and overall phases. A summary of key results from Study 2 is shown in Table 18.
Table 18: Proportion of Patients Responding by Treatment Group and Phase – Cycle 1 in Study 2
|
AKYNZEO Capsules 300 mg netupitant/ 0.5 mg palonosetron
N=724 % |
Palonosetron 0.5 mg
N=725 % |
p-value* |
| PRIMARY ENDPOINT |
| COMPLETE RESPONSE |
| Delayed Phase† |
76.9 |
69.5 |
0.001 |
| MAJOR SECONDARY ENDPOINTS |
| COMPLETE RESPONSE |
| Acute Phase‡ |
88.4 |
85.0 |
0.047 |
| Overall Phase§ |
74.3 |
66.6 |
0.001 |
*p-value from Cochran-Mantel-Haenszel test, stratified by age class and region.
‡Acute phase: 0 to 24 hours after anthracycline and cyclophosphamide regimen.
†Delayed phase: 25 to 120 hours after anthracycline and cyclophosphamide regimen.
§Overall: 0 to 120 hours after anthracycline and cyclophosphamide regimen. |
Multiple Cycles
Patients continued into the Multiple-Cycle extension for up to 7 additional cycles of chemotherapy. The proportion of patients with complete response in the delayed phase by treatment group at each cycle (cycles 2 to 6) is displayed in Figure 1. A limited number of patients received treatment beyond cycle 6. During all cycles the CR rate in the delayed phase was higher for AKYNZEO than for palonosetron. Antiemetic activity of AKYNZEO was maintained throughout repeat cycles for those patients continuing in each of the multiple cycles.
Figure 1: Proportion of Patients with Complete Response in the Delayed Phase by Treatment Group and Cycle in Study 2
Additional clinical trials (Study 3 and Study 4) were conducted to support the efficacy of AKYNZEO.
Study 3 (NCT01376297)
In a separate study, 309 patients undergoing initial and repeat cycles of chemotherapy (including carboplatin, cisplatin, oxaliplatin, and doxorubicin regimens) received AKYNZEO; efficacy was maintained throughout all cycles.
Study 4 (NCT01363479)
In a multicenter, multinational, randomized, active-controlled, double-blind, double-dummy, parallel group, clinical non-inferiority study, the efficacy and safety of a single dose of oral palonosetron 0.5 mg was compared to intravenous palonosetron 0.25 mg in cancer patients scheduled to receive highly emetogenic cisplatin (>70 mg/m²) based chemotherapy. The purpose of this study was to demonstrate that oral palonosetron 0.5 mg contributes to the efficacy of AKYNZEO during the acute phase (first 24 hours after cancer chemotherapy) in the setting of cisplatin based chemotherapy. A total of 739 patients (oral palonosetron n=370; intravenous palonosetron n=369) received study medication.
The primary efficacy endpoint was complete response (CR) (defined as no emetic episode and no use of rescue medication) within 24 hours (acute phase) after the start of cisplatin-based chemotherapy administration. In the oral palonosetron arm, 89.4% of patients achieved a CR in the acute phase compared to 86.2% of patients in the intravenous palonosetron arm, with a difference of 3.2% (99% CI: -2.7% to 9.2%). Non-inferiority of oral palonosetron versus intravenous palonosetron was demonstrated since the lower limit of the two-sided 99% CI for the difference in proportions of patients with CR was greater (i.e., closer to zero) than the pre-defined non-inferiority margin set at -15%.
Study 5 (NCT02557035)
In a multicenter, multinational, randomized, active controlled, double blind, double dummy, parallel group, clinical non-inferiority study, the efficacy and safety of a single dose of intravenous palonosetron 0.25 mg administered over 30 minutes (infusion) was compared to intravenous palonosetron 0.25 mg administered over 30 seconds (bolus) in cancer patients scheduled to receive a HEC chemotherapy regimen that included cisplatin administered as a single IV dose of 70 mg/m², cyclophosphamide 1500 mg/m², carmustine (BCNU) >250mg/m², dacarbazine (DTIC) and mechlorethamine (nitrogen mustard). The purpose of this study was to demonstrate that intravenous palonosetron 0.25 mg administered over 30 minutes was non-inferior to administration of intravenous palonosetron 0.25 mg administered over 30 seconds for prevention of nausea and vomiting during the acute phase (first 24 hours after cancer chemotherapy) in the HEC setting. A total of 425 patients (intravenous palonosetron infusion n=214; intravenous palonosetron bolus n=211) received study medication and HEC and completed the 0-24 h study period with no major protocol violations and were included in the Per Protocol Population.
The primary efficacy endpoint was complete response (CR defined as no emetic episode and no use of rescue medication) in the 24 hours (acute phase) after the start of the scheduled chemotherapy. In the intravenous palonosetron infusion group, 82.7% of patients achieved CR in the acute phase compared to 86.3% of patients in the intravenous palonosetron bolus group, with a difference of -3.4% (99% CI: -12.0% to 5.2%). Non-inferiority of administration of intravenous palonosetron over 30 minutes compared to administration of intravenous palonosetron over 30 seconds was demonstrated since the lower limit of the two-sided 99% CI for the difference in proportions of patients with CR was greater (i.e., closer to zero) than the pre-defined non inferiority margin set at -15%.