PREVYMIS Concentrate for solution for infusion Ref.[115124] Active ingredients: Letermovir

Source: European Medicines Agency (EU)  Revision Year: 2025  Publisher: Merck Sharp & Dohme B.V., Waarderweg 39, 2031 BN Haarlem, The Netherlands

4.3. Contraindications

Hypersensitivity to the active substance or to any of the excipients listed in section 6.1.

Concomitant administration with pimozide (see sections 4.4 and 4.5).

Concomitant administration with ergot alkaloids (see sections 4.4 and 4.5).

Concomitant administration with St. John’s wort (Hypericum perforatum) (see section 4.5).

When letermovir is combined with cyclosporine: Concomitant use of dabigatran, atorvastatin, simvastatin, rosuvastatin or pitavastatin is contraindicated (see section 4.5).

4.4. Special warnings and precautions for use

Monitoring of CMV DNA in HSCT recipients

In a Phase 3 trial (P001), the safety and efficacy of letermovir has been established in HSCT patients with a negative CMV DNA test result prior to initiation of prophylaxis. CMV DNA was monitored on a weekly basis until post-transplant Week 14, and subsequently every two weeks until Week 24. In cases of clinically significant CMV DNAemia or disease, letermovir prophylaxis was stopped and standard-of-care pre-emptive therapy (PET) or treatment was initiated. In patients in whom letermovir prophylaxis was initiated and the baseline CMV DNA test was subsequently found to be positive, prophylaxis could be continued if PET criteria had not been met (see section 5.1).

Risk of adverse reactions or reduced therapeutic effect due to medicinal product interactions

The concomitant use of PREVYMIS and certain medicinal products may result in known or potentially significant medicinal product interactions, some of which may lead to:

  • possible clinically significant adverse reactions from greater exposure of concomitant medicinal products or letermovir.
  • significant decrease of concomitant medicinal product plasma concentrations which may lead to reduced therapeutic effect of the concomi tant medicinal product.

See Table 1 for steps to prevent or manage these known or potentially significant medicinal product interactions, including dosing recommendations (see sections 4.3 and 4.5).

Drug interactions

PREVYMIS should be used with caution with medicinal products that are CYP3A substrates with narrow therapeutic ranges (e.g., alfentanil, fentanyl, and quinidine) as co-administration may result in increases in the plasma concentrations of CYP3A substrates. Close m onitoring and/or dose adjustment of co-administered CYP3A substrates is recommended (see section 4.5).

Increased monitoring of cyclosporine, tacrolimus, sirolimus is generally recommended the first 2 weeks after initiating and ending letermovir (see section 4.5) as well as after changing route of administration of letermovir.

Letermovir is a moderate inducer of enzymes and transporters. Induction may give rise to reduced plasma concentrations of some metabolised and transported medicinal products (see section 4.5).

Therapeutic drug monitoring (TDM) is therefore recommended for voriconazole. Concomitant use of dabigatran should be avoided due to risk of reduced dabigatran efficacy.

Letermovir may increase the plasma concentrations of medicinal products transported by OATP1B1/3 such as many of the statins (see section 4.5 and Tab le 1).

Administration through a sterile 0.2 or 0.22 micron PES in-line filter

PREVYMIS concentrate for solution for infusion may contain a few product-related small translucent or white particles. Administration of PREVYMIS diluted solution always requires the use of a sterile 0.2 micron or 0.22 micron PES in-line filter, regardless of whether these product-related particles are visible in the vial or diluted solution (see sections 4.2 and 6.6).

Excipients

Sodium

This medicinal product contains 23 mg (or 1 mmol) sodium per 240 mg vial, equivalent to 1.15% of the WHO recommended maximum daily intake of 2 g sodium for an adult. This should be taken into consideration by patients on a controlled sodium diet.

This medicinal product contains 46 mg (or 2 mmol) sodium per 480 mg vial, equivalent to 2.30% of the WHO recommended maximum daily intake of 2 g sodium for an adult. This should be taken into consideration by patients on a controlled sodium diet.

Cyclodextrin

This medicinal product contains 1800 mg hydroxypropylbetadex (cyclodextrin) per 12 mL vial (240 mg dose).

This medicinal product contains 3600 mg hydroxypropylbetadex (cyclodextrin) per 24 mL vial (480 mg dose).

4.5. Interaction with other medicinal products and other forms of interaction

General information about differences in exposure between different letermovir treatment regimens

The estimated letermovir plasma exposure is different depending on the dose regimen used (see table in section 5.2). Therefore, the clinical consequences of drug interactions for letermovir will be dependent on which letermovir regimen is used and whether or not letermovir is combined with cyclosporine.

The combination of cyclosporine and letermovir may lead to more marked or additional effects on concomitant medicinal products as compared to letermovir alone (see Table 1).

Effect of other medicinal products on letermovir

The elimination pathways of letermovir in vivo are biliary excretion and glucuronidation. The relative importance of these pathways is unknown. Both elimination pathways involve active uptake into the hepatocyte through the hepatic uptake transporters OATP1B1/3. After uptake, glucuronidation of letermovir is mediated by UGT1A1 and 3. Letermovir also appears to be subject to P-gp and BCRP mediated efflux in the liver and intestine (see section 5.2).

Inducers of drug metabolising enzymes or transporters

Co-administration of PREVYMIS (with or without cyclosporine) with strong and moderate inducers of transporters (e.g., P-gp) and/or enzymes (e.g., UGTs) is not recommended, as it may lead to subtherapeutic letermovir exposure (see Table 1).

Examples of strong inducers include rifampicin, phenytoin, carbamazepine, St. John’s wort (Hypericum perforatum), rifabutin and phenobarbital.

Examples of moderate inducers include thioridazine, modafinil, ritonavir, lopinavir, efavirenz and etravirine.

Rifampicin co-administration resulted in an initial increase in letermovir plasma concentrations (due to OATP1B1/3 and/or P-gp inhibition) that is not clinically relevant, followed by clinically relevant decreases in letermovir plasma concentrations (due to induction of P-gp/UGT) with continued rifampicin co-administration (see Table 1).

Additional effects of other products on letermovir relevant when combined with cyclosporine

Inhibitors of OATP1B1 or 3

Co-administration of PREVYMIS with medicinal products that are inhibitors of OATP1B1/3 transporters may result in increased letermovir plasma concentrations. If PREVYMIS is co-administered with cyclosporine (a potent OATP1B1/3 inhibitor), the recommended dose of PREVYMIS is 240 mg once daily (see Table 1 and sections 4.2 and 5.2). Caution is advised if other OATP1B1/3 inhibitors are added to letermovir combined with cyclosporine.

Examples of OATP1B1 inhibitors include gemfibrozil, erythromycin, clarithromycin, and several protease inhibitors (atazanavir, simeprevir).

Inhibitors of P-gp/BCRP

In vitro results indicate that letermovir is a substrate of P-gp/BCRP. Changes in letermovir plasma concentrations due to inhibition of P-gp/BCRP by itraconazole were not clinically relevant.

Effect of letermovir on other medicinal products

Medicinal products mainly eliminated through metabolism or influenced by active transport

Letermovir is a general inducer in vivo of enzymes and transporters. Unless a particular enzyme or transporter is also inhibited (see below) induction can be expected. Therefore, letermovir may potentially lead to decreased plasma exposure and possibly reduced efficacy of co-administered medicinal products that are mainly eliminated through metabolism or by active transport.

The size of the induction effect is dependent on letermovir route of administration and whether cyclosporine is concomitantly used. The full induction effect can be e xpected after 10-14 days of letermovir treatment. The time needed to reach steady state of a specific affected medicinal product will also influence the time needed to reach full effect on the plasma concentrations.

In vitro, letermovir is an inhibitor of CYP3A, CYP2C8, CYP2B6, BCRP, UGT1A1, OATP2B1, and OAT3 at in vivo relevant concentrations. In vivo studies are available investigating the net effect on CYP3A4, P-gp, OATP1B1/3 additionally on CYP2C19. The net effect in vivo on the other listed enzymes and transporters is not known. Detailed information is presented below. It is unknown whether letermovir may affect the exposure of piperacillin/tazobactam, amphotericine B and micafungin. The potential interaction between letermovir and these medicinal products have not been investigated. There is a theoretical risk of reduced exposure due to induction but the size of the effect and thus clinical relevance is presently unknown.

Medicinal products metabolised by CYP3A

Letermovir is a moderate i nhibitor of CYP3A in vivo. Co-administration of PREVYMIS with oral midazolam (a CYP3A substrate) results in 2-3-fold increased midazolam plasma concentrations. Co-administration of PREVYMIS may result in clinically relevant increases in the plasma concentrations of co-administered CYP3A substrates (see sections 4.3, 4.4, and 5.2).

Examples of such medicinal products include certain immunosuppressants (e.g., cyclosporine, tacrolimus, sirolimus), HMG-CoA reductase inhibitors, and amiodarone (see Table 1). Pimozide and ergot alkaloids are contraindicated (see section 4.3).

The size of the CYP3A inhibitory effect is dependent on letermovir route of administration and whether cyclosporine is concomitantly used.

Due to time dependent inhibition and simultaneous induction the net enzyme inhibitory effect may not be reached until after 10-14 days. The time needed to reach steady state of a specific affected medicinal product will also influence the time needed to reach full effect on the plasma concentrations. When ending treatment, it takes 10-14 days for the inhibitory effect to disappear. If monitoring is applied, this is recommended the first 2 weeks after initiating and ending letermovir (see section 4.4) as well as after changing route of letermovir administration.

Medicinal products transported by OATP1B1/3

Letermovir is an inhibitor of OATP1B1/3 transporters. Administration of PREVYMIS may result in a clinically relevant increase in plasma concentrations of co-administered medicinal products that are OATP1B1/3 substrates.

Examples of such medicinal products include HMG-CoA reductase inhibitors, fexofenadine, repaglinide and glyburide (see Table 1). Comparing letermovir regimen administered without cyclosporine, the effect is more marked after intravenous than oral letermovir.

The magnitude of the OATP1B1/3 inhibition on co-administered medicinal products is likely greater when PREVYMIS is co-administered with cyclosporine (a potent OATP1B1/3 inhibitor). This needs to be considered when the letermovir regimen is changed during treatment with an OATP1B1/3 substrate.

Medicinal products metabolised by CYP2C9 and/or CYP2C19

Co-administration of PREVYMIS with voriconazole (a CYP2C19 substrate) results in significantly decreased voriconazole plasma concentrations, indicating that letermovir is an inducer of CYP2C19. CYP2C9 is likely also induced. Letermovir has the potential to decrease the exposure of CYP2C9 and/or CYP2C19 substrates potentially resulting in subtherapeutic levels.

Examples of such medicinal products include warfarin, voriconazole, diazepam, lansoprazole, omeprazole, esomeprazole, pantoprazole, tilidine, tolbutamide (see Table 1).

The effect is expected to be less pronounced for oral letermovir without cyclosporine, than intravenous letermovir with or without cyclosporine, or oral letermovir with cyclosporine. This needs to be considered when the letermovir regimen is changed during treatment with a CYP2C9 or CYP2C19 substrate. See also general information on induction above regarding time courses of the interaction.

Medicinal products metabolised by CYP2C8

Letermovir inhibits CYP2C8 in vitro but may also induce CYP2C8 based on its induction potential. The net effect in vivo is unknown.

An example of a medicinal product which is mainly eliminated by CYP2C8 is repaglinide (see Table 1). Concomitant use of repaglinide and letermovir with or without cyclosporine is not recommended.

Medicinal products transported by P-gp in the intestine

Letermovir is an inducer of intestinal P-gp. Administration of PREVYMIS may result in a clinically relevant decrease in plasma concentrations of co-administered medicinal products that are significantly transported by P-gp in the intestine such as dabigatran and sofosbuvir.

Medicinal products metabolised by CYP2B6, UGT1A1 or transported by BCRP or OATP2B1

Letermovir is a general inducer in vivo but has also been observed to inhibit CYP2B6, UGT1A1, BCRP, and OATP2B1 in vitro. The net effect in vivo is unknown. Therefore, the plasma concentrations of medicinal products that are substrates of these enzymes or transporters may increase or decrease when co-administered with letermovir. Additional monitoring may be recommended; refer to the prescribing information for such medicinal products.

Examples of medicinal products that are metabolised by CYP2B6 include bupropion.

Examples of medicinal products metabolised by UGT1A1 are raltegravir and dolutegravir.

Examples of medicinal products transported by BCRP include rosuv astatin and sulfasalazine.

An example of a medicinal product transported by OATP2B1 is celiprolol.

Medicinal products transported by the renal transporter OAT3

In vitro data indicate that letermovir is an inhibitor of OAT3; therefore, letermovir may be an OAT3 inhibitor in vivo. Plasma concentrations of medicinal products transported by OAT3 may be increased.

Examples of medicinal products transported by OAT3 includes ciprofloxacin, tenofovir, imipenem, and cilastin.

General information

If dose adjustments of concomitant medicinal products are made due to treatment with PREVYMIS, doses should be readjusted after treatment with PREVYMIS is completed. A dose adjustment may also be needed when changing route of administration or immunosuppre ssant.

Table 1 provides a listing of established or potentially clinically significant medic inal product interactions. The medicinal product interactions described are based on studies conducted with PREVYMIS or are predicted medicinal product interactions that may occur with PREVYMIS (see sections 4.3, 4.4, 5.1, and 5.2).

Table 1. Interactions and dose recommendations with other medicinal products. Note that the table is not extensive but provides examples of clinically relevant interactions. See also the general text on DDIs above.:

Unless otherwise specified, interaction studies have been performed with oral letermovir without cyclosporine. Please note that the interaction potential and clinical consequences may be different depending on whether letermovir is administered orally or intravenous, and whether cyclosporine is concomitantly used. When changing the route of administration, or if changing immunosuppressant, the recommendation concerning co-administration should be revisited.

Concomitant
medicinal product
Effect on concentration
Mean ratio (90% confidence
interval) for AUC, Cmax
(likely mechanism of action)
Recommendations concerning
co-administration with PREVYMIS
Antibiotics
nafcillin Interaction not studied.
Expected:
↓ letermovir

(P-gp/UGT induction)
Nafcillin may decrease plasma
concentrations of letermovir.
Co-administration of PREVYMIS and
nafcillin is not recommended.
Antifungals
fluconazole
(400 mg single
dose)/letermovir
(480 mg single dose)
↔ fluconazole
AUC 1.03 (0.99, 1.08)
Cmax 0.95 (0.92, 0.99)
↔ letermovir
AUC 1.11 (1.01, 1.23)
Cmax 1.06 (0.93, 1.21)

Interaction at steady state not
studied.
Expected;
↔ fluconazole
↔ letermovir
No dose adjustment required.
itraconazole
(200 mg once daily
PO)/letermovir
(480 mg once daily
PO)
↔ itraconazole
AUC 0.76 (0.71, 0.81)
Cmax 0.84 (0.76, 0.92)

↔ letermovir
AUC 1.33 (1.17, 1.51)
Cmax 1.21 (1.05, 1.39)
No dose adjustment required.
posaconazole
(300 mg single
dose)/ letermovir
(480 mg daily)
↔ posaconazole
AUC 0.98 (0.82, 1.17)
Cmax 1.11 (0.95, 1.29)
No dose adjustment required.
voriconazole
(200 mg twice
daily)/ letermovir
(480 mg daily)
↓ voriconazole
AUC 0.56 (0.51, 0.62)
Cmax 0.61 (0.53, 0.71)

(CYP2C9/19 induction)
If concomitant administration is necessary,
TDM for voriconazole is recommended
the first 2 weeks after initiating or ending
letermovir, as well as after changing route
of administration of letermovir or
immunosuppressant.
Antimycobacterials
rifabutin Interaction not studied.
Expected:
↓ letermovir

(P-gp/UGT induction)
Rifabutin may decrease plasma
concentrations of letermovir.
Co-administration of PREVYMIS and
rifabutin is not recommended.
rifampicinMultiple dose rifampicin decreases plasma
concentrations of letermovir.
Co-administration of PREVYMIS and
rifampicin is not recommended.
(600 mg single dose
PO)/ letermovir
(480 mg single dose PO)
↔ letermovir
AUC 2.03 (1.84, 2.26)
Cmax 1.59 (1.46, 1.74)
C24 2.01 (1.59, 2.54)

(OATP1B1/3 and/or P-gp
inhibition)
(600 mg single dose
intravenous)/
letermovir (480 mg
single dose PO)
↔ letermovir
AUC 1.58 (1.38, 1.81)
Cmax 1.37 (1.16, 1.61)
C24 0.78 (0.65, 0.93)

(OATP1B1/3 and/or P-gp
inhibition)
(600 mg once daily
PO)/ letermovir
(480 mg once daily
PO)
↓ letermovir
AUC 0.81 (0.67, 0.98)
Cmax 1.01 (0.79, 1.28)
C24 0.14 (0.11, 0.19)

(Sum of OATP1B1/3 and/or
P-gp inhibition and P-gp/UGT
induction)
(600 mg once daily
PO (24 hours after
rifampicin))§/
letermovir (480 mg
once daily PO)
↓ letermovir
AUC 0.15 (0.13, 0.17)
Cmax 0.27 (0.22, 0.31)
C24 0.09 (0.06, 0.12)

(P-gp/UGT induction)
Antipsychotics
thioridazine Interaction not studied.
Expected:
↓ letermovir

(P-gp/UGT induction)
Thioridazine may decrease plasma
concentrations of letermovir.
Co-administration of PREVYMIS and
thioridazine is not recommended.
Endothelin antagonists
bosentan Interaction not studied.
Expected:
↓ letermovir

(P-gp/UGT induction)
Bosentan may decrease plasma
concentrations of letermovir.
Co-administration of PREVYMIS and
bosentan is not recommended.
Antivirals
acyclovir
(400 mg single
dose)/ letermovir
(480 mg daily)
↔ acyclovir
AUC 1.02 (0.87, 1.2)
Cmax 0.82 (0.71, 0.93)
No dose adjustment required.
valacyclovir Interaction not studied.
Expected:
↔ valacyclovir
No dose adjustment required.
Herbal products
St. John’s wort
(Hypericum
perforatum
)
Interaction not studied.
Expected:
↓ letermovir

(P-gp/UGT induction)
St. John’s wort may decrease plasma
concentrations of letermovir.
Co-administration of PREVYMIS and
St. John’s wort is contraindicated.
HIV medicinal products
efavirenz Interaction not studied.
Expected:
↓ letermovir
(P-gp/UGT induction)

↑ or ↓ efavirenz
(CYP2B6 inhibition or
induction)
Efavirenz may decrease plasma
concentrations of letermovir.
Co-administration of PREVYMIS and
efavirenz is not recommended.
etravirine,
nevirapine, ritonavir,
lopinavir
Interaction not studied.
Expected:
↓ letermovir

(P-gp/UGT induction)
These antivirals may decrease plasma
concentrations of letermovir.
Co-administration of PREVYMIS with
these antivirals is not recommended.
HMG-CoA reductase inhibitors
atorvastatin
(20 mg single dose)/
letermovir (480 mg
daily)
↑ atorvastatin
AUC 3.29 (2.84, 3.82)
Cmax 2.17 (1.76, 2.67)

(CYP3A, OATP1B1/3
inhibition)
Statin-associated adverse events such as
myopathy should be closely monitored.
The dose of atorvastatin should not exceed
20 mg daily when co-administered with
PREVYMIS#.

Although not studied, when PREVYMIS
is co-administered with cyclosporine, the
magnitude of the increase in atorvastatin
plasma concentrations is expected to be
greater than with PREVYMIS alone.
When PREVYMIS is co-administered
with cyclosporine, atorvastatin is
contraindicated.
simvastatin,
pitavastatin,
rosuvastatin
Interaction not studied.
Expected:
↑ HMG-CoA reductase
inhibitors

(CYP3A, OATP1B1/3
inhibition)
Letermovir may substantially increase
plasma concentrations of these statins.
Concomitant use is not recommended with
PREVYMIS alone.

When PREVYMIS is co-administered
with cyclosporine, use of these statins is
contraindicated.
fluvastatin,
pravastatin
Interaction not studied.
Expected:
↑ HMG-CoA reductase
inhibitors

(OATP1B1/3 and/or BCRP
inhibition)
Letermovir may increase statin plasma
concentrations.

When PREVYMIS is co-administered
with these statins, a statin dose reduction
may be necessary#. Statin-associated
adverse events such as myopathy should
be closely monitored.

When PREVYMIS is co-administered
with cyclosporine, pravastatin is not
recommended while for fluvastatin, a dose
reduction may be necessary#. Statin-
associated adverse events such as
myopathy should be closely monitored.
Immunosuppressants
cyclosporine
(50 mg single dose)/
letermovir (240 mg
daily)
↑ cyclosporine
AUC 1.66 (1.51, 1.82)
Cmax 1.08 (0.97, 1.19)
(CYP3A inhibition)
If PREVYMIS is co-administered with
cyclosporine, the dose of PREVYMIS
should be decreased to 2 40 mg once daily
(see sections 4.2 and 5.1).

Frequent monitoring of cyclosporine
whole blood concentrations should be
performed during treatment, when
changing PREVYMIS administration
route, and at discontinuation of
PREVYMIS and the dose of cyclosporine
adjusted accordingly#.
cyclosporine
(200 mg single
dose)/ letermovir
(240 mg daily)
↑ letermovir
AUC 2.11 (1.97, 2.26)
Cmax 1.48 (1.33, 1.65)

(OATP1B1/3 inhibition)
mycophenolate
mofetil
(1 g single dose)/
letermovir (480 mg
daily)
↔ mycophenolic acid
AUC 1.08 (0.97, 1.20)
Cmax 0.96 (0.82, 1.12)

↔ letermovir
AUC 1.18 (1.04, 1.32)
Cmax 1.11 (0.92, 1.34)
No dose adjustment required.
sirolimus
(2 mg single dose)/
letermovir (480 mg
daily)
↑ sirolimus
AUC 3.40 (3.01, 3.85)
Cmax 2.76 (2.48, 3.06)

(CYP3A inhibition)

Interaction not studied.
Expected:
↔ letermovir
Frequent monitoring of sirolimus whole
blood concentrations should be performed
during treatment, when changing
PREVYMIS administration route, and at
discontinuation of PREVYMIS and the
dose of sirolimus adjusted accordingly#.
Frequent monitoring of sirolimus
concentrations is recommended at
initiation or discontinuation of
cyclosporine co-administration with
PREVYMIS.

When PREVYMIS is co-administered
with cyclosporine, also refer to the
sirolimus prescribing information for
specific dosing recommendations for use
of sirolimus with cyclosporine.

When PREVYMIS is co-administered
with cyclosporine, the magnitude of the
increase in concentrations of sirolimus
may be greater than with PREVYMIS
alone.
tacrolimus
(5 mg single dose)/
letermovir (480 mg
daily)
↑ tacrolimus
AUC 2.42 (2.04, 2.88)
Cmax 1.57 (1.32, 1.86)
(CYP3A inhibition)
Frequent monitoring of tacrolimus whole
blood concentrations should be performed
during treatment, when changing
PREVYMIS administration route, and at
discontinuation of PREVYMIS and the
dose of tacrolimus adjusted accordingly#.
tacrolimus
(5 mg single dose)/
letermovir (80 mg
twice daily)
↔ letermovir
AUC 1.02 (0.97, 1.07)
Cmax 0.92 (0.84, 1)
Oral contraceptives
ethinylestradiol (EE)
(0.03 mg)/
levonorgestrel
(LNG)
(0.15 mg) single
dose/ letermovir
(480 mg daily)
↔ EE
AUC 1.42 (1.32, 1.52)
Cmax 0.89 (0.83, 0.96)

↔ LNG
AUC 1.36 (1.30, 1.43)
Cmax 0.95 (0.86, 1.04)
No dose adjustment required.
Other systemically
acting oral
contraceptive
steroids
Risk of ↓ contraceptive
steroids
Letermovir may reduce plasma
concentrations of other oral contraceptive
steroids thereby affecting their efficacy.
For adequate contraceptive effect to be
ensured with an oral contraceptive,
products containing EE and LNG should be
chosen.
Antidiabetic medicinal products
repaglinide Interaction not studied.
Expected:
↑ or ↓ repaglinide

(CYP2C8 induction, CYP2C8
and OATP1B inhibition)
Letermovir may increase or decrease the
plasma concentrations of repaglinide. (The
net effect is not known).

Concomitant use is not recommended.

When PREVYMIS is co-administered
with cyclosporine, the plasma
concentrations of repaglinide is expected
to increase due to the additional OATP1B
inhibition by cyclosporine. Concomitant
use is not recommended#.
glyburide Interaction not studied.
Expected:
↑ glyburide

(OATP1B1/3 inhibition
CYP3A inhibition, CYP2C9
induction)
Letermovir may increase the plasma
concentrations of glyburide.

Frequent monitoring of glucose
concentrations is recommended the first
2 weeks after initiating or ending
letermovir, as well as after changing route
of administration of letermovir.

When PREVYMIS is co-administered
with cyclosporine, refer also to the
glyburide prescribing information for
specific dosing recommendations.
Antiepileptic medicinal products (see also general text)
carbamazepine,
phenobarbital
Interaction not studied.
Expected:
↓ letermovir

(P-gp/UGT induction)
Carbamazepine or phenobarbital may
decrease plasma concentrations of
letermovir.
Co-administration of PREVYMIS and
carbamazepine or phenobarbital is not
recommended.
phenytoin Interaction not studied.
Expected:
↓ letermovir

(P-gp/UGT induction)

↓ phenytoin

(CYP2C9/19 induction)
Phenytoin may decrease plasma
concentrations of letermovir.

Letermovir may decrease the plasma
concentrations of phenytoin.

Co-administration of PREVYMIS and
phenytoin is not recommended.
Oral anticoagulants
warfarin Interaction not studied.
Expected:
↓ warfarin

(CYP2C9 induction)
Letermovir may decrease the plasma
concentrations of warfarin.

Frequent monitoring of International
Normalised Ratio (INR) should be
performed when warfarin is
co-administered with PREVYMIS treatment#.
Monitoring is recommended the first
2 weeks after initiating or ending
letermovir, as well as after changing route
of administration of letermovir or
immunosuppress ant.
dabigatran Interaction not studied.
Expected:
↓ dabigatran

(intestinal P-gp induction)
Letermovir may decrease the plasma
concentrations of dabigatran and may
decrease efficacy of dabigatran.
Concomitant use of dabigatran should be
avoided due to the risk of reduced
dabigatran efficacy.

When PREVYMIS is co-administered
with cyclosporine, dabigatran is
contraindicated.
Sedatives
midazolam
(1 mg single dose
intravenous)/
letermovir (240 mg
once daily PO)

midazolam (2 mg
single dose PO) /
letermovir (240 mg
once daily PO)
↑ midazolam
intravenous:
AUC 1.47 (1.37, 1.58)
Cmax 1.05 (0.94, 1.17)

PO:
AUC 2.25 (2.04, 2. 48)
Cmax 1.72 (1.55, 1.92)

(CYP3A inhibition)
Close clinical monitoring for respiratory
depression and/or prolonged sedation
should be exercised during
co-administration of PREVYMIS with
midazolam. Dose adjustment of
midazolam should be considered#. The
increase in midazolam plasma
concentration may be greater when oral
midazolam is administered with letermovir
at the clinical dose than with the dose
studied.
Opioid agonists
Examples: alfentanil,
fentanyl
Interaction not studied.
Expected:
↑ CYP3A metabolised opioids

(CYP3A inhibition)
Frequent monitoring for adverse reactions
related to these medicinal products is
recommended during co-administration.
Dose adjustment of CYP3A metabolised
opioids may be needed# (see section 4.4).
Monitoring is also recommended if
changing route of administration. When
PREVYMIS is co-administered with
cyclosporine , the magnitude of the
increase in plasma concentrations of
CYP3A metabolised opioids may be
greater. Close clinical monitoring for
respiratory depression and/or prolonged
sedation should be exercised during
co-administration of PREVYMIS in
combination with cyclosporine and
alfentanil or fentanyl. Refer to the
respective prescribing information (see
section 4.4).
Anti-arrhythmic medicinal products
amiodarone Interaction not studied.
Expected:
↑ amiodarone

(primarily CYP3A inhibition
and CYP2C8 inhibition or
induction)
Letermovir may increase the plasma
concentrations of amiodarone.

Frequent monitoring for adverse reactions
related to amiodarone is recommended
during co-administration. Monitoring of
amiodarone concentrations should be
performed regularly when amiodarone is
co-administered with PREVYMIS#.
quinidine Interaction not studied.
Expected:
↑ quinidine

(CYP3A inhibition)
Letermovir may increase the plasma
concentrations of quinidine.

Close clinical monitoring should be
exercised during administration of
PREVYMIS with quinidine. Refer to the
respective prescribing information#.
Cardiovascular medicinal products
digoxin
(0.5 mg single dose)/
letermovir (240 mg
twice daily)
↔ digoxin
AUC 0.88 (0.80, 0.96)
Cmax 0.75 (0.63, 0.89)

(P-gp induction)
No dose adjustment required.
Proton pump inhibitors
omeprazole Interaction not studied.
Expected:
↓ omeprazole

(induction of CYP2C19)

Interaction not studied.
Expected:
↔ letermovir
Letermovir may decrease the plasma
concentrations of CYP2C19 substrates.

Clinical monitoring and dose adjustment
may be needed.
pantoprazole Interaction not studied.
Expected:
↓ pantoprazole

(likely due to induction of
CYP2C19)

Interaction not studied.
Expected:
↔ letermovir
Letermovir may decrease the plasma
concentrations of CYP2C19 substrates.

Clinical monitoring and dose adjustment
may be needed.
Wakefulness-promoting agents
modafinil Interaction not studied.
Expected:
↓ letermovir

(P-gp/UGT induction)
Modafinil may decrease plasma
concentrations of letermovir.
Co-administration of PREVYMIS and
modafinil is not recommended.

* This table is not all inclusive.
↓ = decrease, ↑ = increase
↔ = no clinically relevant change
One-way interaction study assessing the effect of letermovir on the concomitant medicinal product.
§ These data are the effect of rifampicin on letermovir 24 hours after final rifampicin dose.
# Refer to the respective prescribing information.

Paediatric population

Interaction studies have only been performed in adults.

4.6. Fertility, pregnancy and lactation

Pregnancy

There are no data from the use of letermovir in pregnant women. Studies in animals have shown reproductive toxicity (see section 5.3).

PREVYMIS is not recommended during pregnancy and in women of childbearing potential not using contraception.

Breast-feeding

It is unknown whether letermovir is excreted in human milk. Available pharmacodynamic/toxicological data in animals have shown excretion of letermovir in milk (see section 5.3).

A risk to the newborns/infants cannot be excluded.

A decision must be made whether to discontinue breast-feeding or to discontinue/abstain from PREVYMIS therapy taking into account the benefit of breast-feeding for the child and the benefit of therapy for the woman.

Fertility

There were no effects on female fertility in rats. Irreversible testicular toxicity and impairment of fertility was observed in male rats, but not in male mice or male monkeys.

4.7. Effects on ability to drive and use machines

PREVYMIS may have minor influence on the ability to drive or use machines. Fatigue and vertigo have been reported in some patients during treatm ent with PREVYMIS, which may influence a patient’s ability to drive and use machines (see section 4.8).

4.8. Undesirable effects

Summary of the safety profile

The safety assessment of PREVYMIS was based on three Phase 3 clinical trials.

HSCT

In P001, 565 HSCT recipients received PREVYMIS or placebo through Week 14 post-transplant and were followed for safety through Week 24 post-transplant (see section 5.1). The most commonly reported adverse reactions occurring in at least 1% of subjects in the PREVYMIS group and at a frequency greater than placebo were: nausea (7.2%), diarrhoea (2.4%), and vomiting (1.9%). The most frequently reported adverse reactions that led to discontinuation of PREVYMIS were: nausea (1.6%), vomiting (0.8%), and abdominal pain (0.5%).

In P040, 218 HSCT recipients received PREVYMIS or placebo from Week 14 (~100 days) through Week 28 (~200 days) post-HSCT and were followed for safety through Week 48 post-HSCT (see section 5.1). The adverse reactions reported were consistent with the safety profile of PREVYMIS as characterised in study P001.

Kidney transplant

In P002, 292 kidney transplant recipients received PREVYMIS through Week 28 (~200 days) post-transplant (see section 5.1).

Tabulated summary of adverse reactions

The following adverse reactions were identified in patients taking PREVYMIS in clinical trials. The adverse reactions are listed below by body system organ class and frequency. Frequencies are defined as follows: very common (≥1/10), common (≥1/100 to <1/10), uncommon (≥1/1,000 to <1/100), rare (≥1/10,000 to <1/1,000) or very rare (<1/10,000).

Table 2. Adverse reactions identified with PREVYMIS:

Frequency Adverse reactions
Immune system disorders
Uncommon hypersensitivity
Metabolism and nutrition disorders
Uncommon decreased appetite
Nervous system disorders
Uncommon dysgeusia, headache
Ear and labyrinth disorders
Uncommon vertigo
Gastrointestinal disorders
Common nausea, diarrhoea, vomiting
Uncommon abdominal pain
Hepatobiliary disorders
Uncommon alanine aminotransferase increased, aspartate
aminotransferase increased
Musculoskeletal and connective tissue disorders
Uncommon muscle spasms
Renal and urinary disorders
Uncommon blood creatinine increased
General disorders and administration site conditions
Uncommon fatigue, oedema peripheral

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the national reporting system listed in Appendix V.

6.2. Incompatibilities

Incompatible medicinal products

PREVYMIS concentrate for solution for infusion is physically incompatible with amiodarone hydrochloride, amphotericin B (liposomal), aztreonam, cefepime hydrochloride, ciprofloxacin, cyclosporine, diltiazem hydrochloride, filgrastim, gentamicin sulphate, levofloxacin, linezolid, lorazepam, midazolam HCl, mycophenolate mofetil hydrochloride, ondansetron, palonosetron.

This medicinal product must not be mixed with other medicinal products except those mentioned in section 6.6.

Incompatible intravenous bags and infusion set materials

PREVYMIS concentrate for solution for infusion is incompatible with diethylhexyl phthalate (DEHP) plasticizers and polyurethane-containing intravenous administration set tubing.

This medicinal product must not be used with other intravenous bags and infusion set materials except those mentioned in section 6.6.

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