Cladribine

Table 3 Drug Interactions with MAVENCLAD

7.1 Immunomodulatory, Immunosuppressive, or Myelosuppressive Drugs Clinical Impact Concomitant use of MAVENCLAD with immunomodulatory, immunosuppressive, or myelosuppressive drugs may increase the risk of adverse reactions because of the additive effects on the immune system [see Warnings and Precautions (5.4) ] . Prevention or Management Concomitant use with myelosuppressive or other immunosuppressive drugs is not recommended. Acute short- term therapy with corticosteroids can be administered.

In patients who have previously been treated with immunomodulatory or immunosuppressive drugs, consider potential additive effect, the mode of action, and duration of effect of the other drugs prior to initiation of MAVENCLAD.

7.2 Interferon-Beta Clinical Impact Concomitant use of MAVENCLAD with interferon-beta did not change the exposure of cladribine to a clinically significant effect; however, lymphopenia risk may be increased [see Warnings and Precautions (5.3) ]. Prevention or Management Concomitant use is not recommended.

7.3 Hematotoxic Drugs Clinical Impact Concomitant use of MAVENCLAD with hematotoxic drugs may increase the risk of adverse reactions because of the additive hematological effects [see Warnings and Precautions (5.5) ]. Prevention or Management Monitor hematological parameters.

7.4 Antiviral and Antiretroviral Drugs Clinical Impact Compounds that require intracellular phosphorylation to become active (e.g., lamivudine, zalcitabine, ribavirin, stavudine, and zidovudine) could interfere with the intracellular phosphorylation and activity of cladribine. Prevention or Management Avoid concomitant use .

7.5 Potent ENT, CNT and BCRP Transporter Inhibitors Clinical Impact Cladribine is a substrate of breast cancer resistance protein (BCRP), equilibrative nucleoside (ENT1), and concentrative nucleoside (CNT3) transport proteins. The bioavailability, intracellular distribution, and renal elimination of cladribine may be altered by potent ENT1, CNT3, and BCRP transporter inhibitors. Prevention or Management Avoid co-administration of potent ENT1, CNT3, or BCRP transporter inhibitors (e.g., ritonavir, eltrombopag, curcumin, cyclosporine, dilazep, nifedipine, nimodipine, cilostazol, sulindac, dipyridamole, or reserpine) during the 4 to 5 day MAVENCLAD treatment cycles.

If this is not possible, consider selection of alternative concomitant drugs with no or minimal ENT1, CNT3, or BCRP transporter inhibiting properties. If this is not possible, dose reduction to the minimum mandatory dose of drugs containing these compounds, separation in the timing of administration, and careful patient monitoring is recommended.

7.6 Potent BCRP and P-gp Transporter Inducers Clinical Impact Possible decrease in cladribine exposure if potent BCRP or P-gp transporter inducers are co-administered. Prevention or Management Consider a possible decrease in cladribine efficacy if potent BCRP (e.g., corticosteroids) or P-gp (e.g., rifampicin, St. John's Wort) transporter inducers are co-administered. Immunosuppressive drugs: Consider overlapping effects on immune system, when used sequentially. Concomitant use not recommended. ( 7.1 ) Hematotoxic drugs: Monitor patients for additive effects on the hematological profile. ( 7.3 ) Antiviral and antiretroviral drugs: Avoid concomitant use.

( 7.4 ) BCRP or ENT/CNT inhibitors: May alter bioavailability of cladribine. Avoid concomitant use. ( 7.5 )

8.1 Pregnancy Risk Summary MAVENCLAD is contraindicated in pregnant women and in females and males of reproductive potential who do not plan to use effective contraception. There are no adequate data on the developmental risk associated with use of MAVENCLAD in pregnant women. Cladribine was embryolethal when administered to pregnant mice and produced malformations in mice and rabbits [see Data ] . The observed developmental effects are consistent with the effects of cladribine on DNA [see Contraindications (4) and Warnings and Precautions (5.2) ]. In the U.S.

general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. The background risk of major birth defects and miscarriage for the indicated population is unknown. There is a pregnancy safety study that monitors the pregnancy and infant outcomes following exposure to cladribine.

Physicians and patients are encouraged to report pregnancies of female patients with multiple sclerosis exposed to oral cladribine during pregnancy or within 6 months before conception as well as pregnancies fathered by male patients with multiple sclerosis who had taken oral cladribine within 14 weeks before conception by calling EMD Serono's Adverse Event reporting line at 1-800-283-8088 ext. 5563 or by faxing 1-781-681-2961.

Data Animal Data When cladribine was administered intravenously (0, 0.5, 1.5, or 3 mg/kg/day) to pregnant mice during the period of organogenesis, fetal growth retardation and malformations (including exencephaly and cleft palate) and embryofetal death were observed at the highest dose tested. An increase in skeletal variations was observed at all but the lowest dose tested. There was no evidence of maternal toxicity.

When cladribine was administered intravenously (0, 0.3, 1, and 3 mg/kg/day) to pregnant rabbits during the period of organogenesis, fetal growth retardation and a high incidence of craniofacial and limb malformations were observed at the highest dose tested, in the absence of maternal toxicity. When cladribine was administered intravenously (0, 0.5, 1.5, or 3.0 mg/kg/day) to mice throughout pregnancy and lactation, skeletal anomalies and embryolethality were observed at all but the lowest dose tested.