Prescribing information

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Hero Banner. KESIMPTA®▼ (ofatumumab) logo.

KESIMPTA®▼ (ofatumumab) safety profile and side effects

KESIMPTA is indicated for the treatment of adult patients with relapsing forms of multiple sclerosis (RMS) with active disease defined by clinical or imaging features.1

Please refer to the Summary of Product Characteristics (SmPC) for full safety information.


KESIMPTA demonstrated a generally well tolerated safety profile similar to teriflunomide, maintained up to 7 years1–3


ASCLEPIOS I and II study design:1,2

 

  • Two double-blind, double-dummy, Phase III trials
  • Participants had RMS
  • Participants were randomised to receive subcutaneous (SC) KESIMPTA (20 mg every 4 weeks after 20 mg loading doses at Days 1, 7, and 14) (n=946) or oral teriflunomide (14 mg daily) for up to 30 months (n=936)*

 

In ASCLEPIOS I and II:

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KESIMPTA resulted in infection rates similar to teriflunomide in Phase III studies1

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Icon of an injection pen representing injection-related reactions.

Injection-related reactions were mostly (99.8%) mild to moderate in severity1

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Warning triangle icon.

No unexpected safety risks were identified in cumulative safety data up to 7 years3

Overall safety profiles up to 7 years
 

 Core, ASCLEPIOSCore + extension:
Overall KESIMPTA,
(N=1969)
Core + extension:
RDTN KESIMPTA,
(n=546)
KESIMPTA, n
(%)
KESIMPTA,
EAIR (95% CI)
TER, n
(%)
TER, EAIR
(95% CI)
n
(%)
EAIR
(95% CI)
n
(%)
EAIR
(95% CI)
Participants with at least one AE791
(83.61)
188.55
(175.86–202.16)
788
(84.2)
188.92
(176.18–202.58)
1826
(92.7)
112.95
(107.88–118.25)
509
(93.2)
124.96
(114.56–136.30)
Participants with at least one SAE83
(8.77)
5.56
(4.48–6.89)
73
(7.8)
4.94
(3.93–6.21)
342
(17.4)
4.06
(3.65–4.51)
87
(15.9)
3.70
(3.00–4.57)
AEs leading to KESIMPTA discontinuation54
(5.70)
49
(5.2)

151
(7.7)
52
(9.5)
Infections and infestations488
(51.58)
51.14
(46.80–55.88)
493
(52.7)
52.59
(48.14–57.44)
1423
(72.3)
37.12
(35.24–39.10)
411
(75.3)
42.31
(38.41–46.60)
Serious infections24
(2.54)
1.55
(1.04–2.31)
17
(1.8)
1.12
(0.69–1.80)
123
(6.2)
1.37
(1.15–1.63)
Serious infections (excluding COVID-19)24
(2.54)
1.55
(1.04–2.31)
17
(1.8)
1.12
(0.69–1.80)
78
(4.0)
0.86
(0.69–1.07)
16
(2.9)
0.63
(0.39–1.03)
Serious COVID-19 infections000051
(2.6)
0.55
(0.42–0.73)
18
(3.3)
0.70
(0.44–1.12)
Blood Ig level        
IgG decrease8
(0.5)
0.09
(0.04–0.17)
2
(0.4)
0.08
(0.02–0.31)
IgM decrease284
(14.4)
3.30
(2.94–3.71)
79
(14.4)
3.28
(2.63–4.09)
Injection-related systemic reactions195
(20.61)
15.49
(13.46–17.83)
143
(15.3)
10.90
(9.25–12.84)
516
(26.1)
7.38
(6.77–8.04)
142
(26.0)
7.16
(6.08–8.44)
Injection-site reactions103
(10.88)
7.21
(5.94–8.74)
52
(5.55)
3.54
(2.70–4.65)
261
(13.3)
3.16
(2.80–3.57)
87
(15.9)
3.86
(3.13–4.76)
Malignancies5
(0.53)
0.32
(0.13–0.77)
4
(0.4)
0.26
(0.10–0.69)
29
(1.5)
0.31
(0.22–0.45)
10
(1.8)
0.38
(0.21–0.72)
Deaths01§127||
(1.3)
 

Adapted from Weindl H, et al. 2024,4 Hauser SL, et al. 20255 and Bittner S, et al. 2025.6

Treatment-emergent AEs recorded in ASCLEPIOS2

 

 

KESIMPTA (n=946)

Teriflunomide (n=936)

Any AEs

791 (83.6)

788 (84.2)

Any serious AEs

86 (9.1)

74 (7.9)

Most common AEs

Injection-related reactions (systemic)**

195 (20.6)

143 (15.3)

Nasopharyngitis

170 (18.0)

156 (16.7)

Headache

126 (13.3)

116 (12.4)

Injection-site reaction (local)

103 (10.9)

52 (5.6)

Upper respiratory tract infection

97 (10.3)

120 (12.8)

Urinary tract infection

97 (10.3)

78 (8.3)

Back pain

72 (7.6)

58 (6.2)

Fatigue

71 (7.5)

72 (7.7)

Influenza

62 (6.6)

59 (6.3)

Nausea

61 (6.4)

64 (6.8)

Blood IgM decreased

56 (5.9)

21 (2.2)

Alopecia

54 (5.7)

138 (14.7)

Arthralgia

49 (5.2)

44 (4.7)

Diarrhoea

49 (5.2)

111 (11.9)

Pain in extremity

46 (4.9)

66 (7.1)

Depression

45 (4.8)

48 (5.1)

Hypertension

35 (3.7)

55 (5.9)

Paraesthesia

27 (2.9)

52 (5.6)

Data are n (%)

Adapted from Hauser SL, et al. 2020.2

 

Treatment discontinuations2

Discontinuation:

KESIMPTA (n=946)

Teriflunomide (n=936)

Due to an AE

54 (5.7%)

49 (5.2%)

Due to an injection reaction (systemic)

1 (0.1%)

N/A

Adapted from Hauser SL, et al. 2020.2

 

EAIRs per 100 PYs of AEs and SAEs with up to 7 years of ofatumumab treatment remained generally consistent with that in the ASCLEPIOS I/II trials, with no unexpected safety concerns identified5

EAIRs of serious AEs, including infections and malignancies, remained consistent up to 7 years5

EAIR per 100 PYs is defined as the expected number of patients with the given event over 100 years of exposure to a treatment, assuming the event rate is constant over time. This is estimated by Poisson regression where participants’ time is taken until first event occurrence, or the last day the patient was at risk, for those who did not have the event.5


Adverse reactions in the SmPC

The most important and frequently reported adverse reactions are upper respiratory tract infections (39.4%), systemic injection-related reactions (20.6%), injection-site reactions (10.9%) and urinary tract infections (11.9%).1

Infections and infestations
Very commonUpper respiratory tract infections††
Urinary tract infections‡‡
CommonOral herpes
Immune system disorders
Not knownHypersensitivity reactions§§
General disorders and administration site conditions
Very commonInjection-site reactions (local)
Injury, poisoning and procedural complications
Very commonInjection-related reactions (systemic)
Gastrointestinal disorders
CommonNausea, vomiting¶¶
Investigations
CommonBlood IgM decreased

Adapted from KESIMPTA (ofatumumab) Summary of Product Characteristics.1

Please refer to the SmPC for full safety information.1

Frequency is categorised as: Very common (≥1/10); common (≥1/100 to <1/10); uncommon (≥1/1000 to <1/100); rare (≥1/10,000 to <1/1000); very rare (<1/10,000).1

Learn more about B-cell depletion data

How does KESIMPTA impact IgG and IgM serum levels vs teriflunomide in the ALITHIOS trial?

 

ALITHIOS study design:4

  • Open-label, single-arm, multi-centre extension of ASCLEPIOS I/II, APLIOS and APOLITOS trials

  • Objective: to assess the longer-term safety and efficacy of KESIMPTA in people with relapsing multiple sclerosis (pwRMS)

  • Efficacy population for ALITHIOS included 1882 who entered from ASCLEPIOS I/II (including continuous and switch KESIMPTA groups). Safety population for ALITHIOS includes patients from APLIOS and APOLITOS. A total of 1969 patients were included in the safety analysis

  • At data cut-off, September 2024, patients had experienced up to 7 years of KESIMPTA treatment5

For further information on the clinical trials, please click here.

 

IgG levels 

Use the arrows below to navigate to the RTDN subgroup data.

 

 

In the Phase III studies, KESIMPTA was associated with a transient decrease of 4.3% in mean IgG levels after 48 weeks of treatment but an increase of 2.2% after 96 weeks.1 The 7-year data reported interruptions/discontinuations in 3 (0.2%)/4 (0.2%) patients due to low IgG.5

In ASCLEPIOS I/II, the investigators were required to interrupt study treatment if IgM levels fell 10% <LLN or IgG levels fell 20% <LLN; due to a protocol amendment at the beginning of ALITHIOS (3 June 2021), the requirement to interrupt treatment based on a specific threshold due to low IgG/IgM was removed, and the decision was left to the discretion of the investigator.4

 

IgM levels 

Use the arrows below to navigate to the RTDN subgroup data.

 

In the Phase III clinical studies, a decrease in mean value of IgM (30.9% decrease after 48 weeks and 38.8% decrease after 96 weeks) was observed.1

In the 7-year data, treatment interruptions/discontinuations due to low IgM was reported in 9.7%/4.2% RDTN patients.6

In ASCLEPIOS I/II, the investigators were required to interrupt study treatment if IgM levels fell 10% <LLN or IgG levels fell 20% <LLN; due to a protocol amendment at the beginning of ALITHIOS (3 June 2021), the requirement to interrupt treatment based on a specific threshold due to low IgG/IgM was removed, and the decision was left to the discretion of the investigator.4

How does KESIMPTA (ofatumumab) impact lymphocyte and neutrophil levels vs teriflunomide?

 

Lymphocyte levels up to 6 years4

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Line graph showing mean lymphocyte levels compared to teriflunomide throughout 6 years of treatment with KESIMPTA.

Adapted from Wiendl H, et al. 2024.4

Up to Year 7: A transient decline in the mean lymphocyte levels was observed up to Week 4 (% change: continuous, −11.9%; switch, −8.2%), followed by an increase back close to baseline levels in continuous KESIMPTA and switch groups which was sustained through Week 360.5

Mean lymphocyte levels were observed to remain generally stable for up to 7 years of treatment with KESIMPTA in a post-hoc analysis5

 

Neutrophil levels up to 6 years4

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Line graph showing mean neutrophil levels compared to teriflunomide. throughout 6 years of treatment with KESIMPTA.

Adapted from Wiendl H, et al. 2024.4

Up to Year 7: In the continuous KESIMPTA group, the mean neutrophil level remained stable and above baseline for all visits up to Week 360; whereas in the switch group, the mean neutrophil level decreased up to Week 4 (−14.5%) and remained low during the pre-switch period followed by a reversal and stabilisation (reaching baseline levels) post-switch.5

Mean neutrophil levels were observed to remain generally stable for up to 7 years of treatment with KESIMPTA in a post-hoc analysis5

Safety considerations and precautions1


Please refer to the SmPC for full safety information.1

 

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Icon of a hand representing Gd+ T1 lesions AND new or enlarging T2 lesions.

Contraindications1

 
  • Hypersensitivity to the active substance or to any of the excipients in KESIMPTA

  • Patients in a severely immunocompromised state

  • Severe active infection until resolution

  • Known active malignancy

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Label icon representing KESIMPTA traceability.

Traceability1

  
  • In order to improve the traceability of biological medicinal products, the name and the batch number of the administered product should be clearly recorded.

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Exclamation mark icon.

Treatment of severely immunocompromised patients1

  
  • Patients in a severely immunocompromised state must not be treated until the condition resolves

  • It is not recommended to use other immunosuppressants concomitantly with KESIMPTA except corticosteroids for symptomatic treatment of relapses

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Syringe icon.

Vaccinations1

 
  • Vaccination with live or live-attenuated vaccines is not recommended during treatment with KESIMPTA and after discontinuation until B-cell repletion; all immunisations should be administered according to immunisation guidelines at least 4 weeks prior to initiation of KESIMPTA for live or live-attenuated vaccines and, whenever possible, at least 2 weeks prior to initiation of KESIMPTA for inactivated vaccines 

  • KESIMPTA may interfere with the effectiveness of inactivated vaccines. Inactivated vaccines, whenever possible, should be administered at least 2 weeks prior to initiation of KESIMPTA according to immunisation guidelines 

  • The safety of immunisation with live or live-attenuated vaccines following KESIMPTA therapy has not been studied

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Icon of a home with a heart inside depicting paediatric population.

Pregnancy and family planning1

 
  • Women of childbearing potential should use effective contraception (methods that result in less than 1% pregnancy rates) while receiving KESIMPTA and for 6 months after the last administration of KESIMPTA, as there is a limited amount of data from the use of KESIMPTA in pregnant women

  • Treatment with KESIMPTA should be avoided during pregnancy unless the potential benefit to the mother outweighs the potential risk to the foetus

  • KESIMPTA may cross the placenta and cause foetal B-cell depletion based on findings from animal studies

  • The use of KESIMPTA in women during lactation has not been studied. It is unknown whether KESIMPTA is excreted in human milk. In humans, excretion of IgG antibodies in milk occurs during the first few days after birth, and decreases to low concentrations soon afterwards. Consequently, a risk to the breastfed child cannot be excluded during this short period. Afterwards, KESIMPTA could be used during breastfeeding if clinically needed. However, if the patient was treated with KESIMPTA up to the last few months of pregnancy, breastfeeding can be started immediately after birth

  • There are no data on the effect of KESIMPTA on human fertility

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Syringe icon.

Vaccination of infants born to mothers treated with KESIMPTA during pregnancy1

 
  • In infants of mothers treated with KESIMPTA during pregnancy, live or live-attenuated vaccines should not be administered before the recovery of B-cell counts has been confirmed. Depletion of B-cells in these infants may increase the risks from live or live-attenuated vaccines

  • Inactivated vaccines may be administered as indicated prior to recovery from B-cell depletion; however, assessment of vaccine immune responses, including consultation with a qualified specialist, should be considered to determine whether a protective immune response was mounted

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Icon representing infections.

Infections1

 
  • It is recommended to evaluate the patient’s immune status prior to initiating therapy

  • Based on its mode of action and available clinical experience, KESIMPTA has the potential for an increased risk of infections. Administration should be delayed in patients with an active infection until the infection is resolved

  • KESIMPTA must not be given to patients in a severely immunocompromised state (e.g. significant neutropenia or lymphopenia)

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Icon representing infections.

Progressive multifocal leukoencephalopathy (PML)1

 
  • Physicians should be vigilant for medical history of PML and for any clinical symptoms or magnetic resonance imaging findings that may be suggestive of PML. If PML is suspected, treatment with KESIMPTA should be suspended until PML has been excluded

 

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Circle with the letters HBV.

Hepatitis B virus (HBV) reactivation1

 
  • HBV reactivation has occurred in patients treated with anti-CD20 antibodies, which in some cases resulted in fulminant hepatitis, hepatic failure and death

  • Patients with active HBV disease should not be treated with KESIMPTA. HBV screening should be performed in all patients before initiation of treatment. As a minimum, screening should include HBV surface antigen (HBsAg) and HBV core antibody (HBcAb) testing. These can be complemented with other appropriate markers as per local guidelines. Patients with positive HBV serology (either HBsAg or HBcAb) should consult a liver disease expert before the start of treatment and should be monitored and managed following local medical standards to prevent HBV reactivation

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Sensoready pen icon.

Injection-related reactions1

 
  • Patients should be informed that systemic injection‑related reactions could occur, generally within 24 hours and predominantly following the first injection

  • Symptoms most frequently observed in relapsing forms of multiple sclerosis (RMS) clinical studies include fever, headache, myalgia, chills, fatigue, nausea and vomiting, and were predominantly (99.8%) mild to moderate in severity. There were no life-threatening systemic injection‑related reactions reported in RMS clinical studies

  • Additional systemic injection‑related reactions reported in the post-marketing setting include rash, urticaria, dyspnoea and angioedema (e.g. tongue, pharyngeal or laryngeal swelling), and rare cases which were reported as anaphylaxis. While there were some cases which were serious and resulted in discontinuation of KESIMPTA treatment, there were also serious cases where patients were able to continue KESIMPTA treatment without further incidents

  • Some systemic injection‑related reaction symptoms may be clinically indistinguishable from Type 1 acute hypersensitivity reactions (immunoglobulin E (IgE)-mediated). A hypersensitivity reaction may present during any injection, although typically would not present with the first injection. For subsequent injections, more severe symptoms than previously experienced, or new severe symptoms, should prompt consideration of a potential hypersensitivity reaction. Patients with known IgE-mediated hypersensitivity to KESIMPTA must not be treated with KESIMPTA

  • Only limited benefit of premedication with steroids was seen in RMS clinical studies. Injection-related reactions can be managed with symptomatic treatment, should they occur. Therefore, use of premedication is not required

  • Injection site reaction (local) symptoms observed in clinical studies included erythema, swelling, itching and pain

  • The first injection should be performed under the guidance of an appropriately trained healthcare professional

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Icon of an immune cell.

Other immunosuppressive or immune-modulating therapies1

 
  • The risk of additive immune system effects should be considered when co-administering immunosuppressive therapies with KESIMPTA

  • When initiating KESIMPTA after other immunosuppressive therapies with prolonged immune effects or initiating other immunosuppressive therapies with prolonged immune effects after KESIMPTA, the duration and mode of action of these medicinal products should be taken into account because of potential additive immunosuppressive effects


*Patients in the teriflunomide arm received a matching placebo injection to ensure blinding (double-dummy design).
IgG and IgM levels remained above the LLN (5.65 g/L) in 96.8% and 64.5% of patients at all visits, respectively; the proportion of participants who interrupted ofatumumab treatment due to low IgG or IgM was 0.4% and 14%, respectively.
One case of basal cell carcinoma was not listed as an SAE.4 
§Death was due to aortic dissection.4
Including the following: Sudden death (n=1), oesophageal adenocarcinoma (n=1), completed suicide (n=1), COVID-19/COVID-19 pneumonia (n=1), COVID-19 (n=2), gastric ulcer perforation (n=1), COVID-19 pneumonia (n=1), intestinal metastasis (n=1), COVID-19 pneumonia/pneumothorax (n=1), pneumonia/septic shock (n=1) and injury (n=1).5
Including the following: Sudden death (n=1), oesophageal adenocarcinoma (n=1), completed suicide (n=1), aortic dissection (n=1), COVID-19/COVID-19 pneumonia (n=1) and COVID-19 (n=2).6
**Only reactions or symptoms that occurred within 24 hours after injection are included (i.e., time to onset of reaction ≤24 hours).2
††Grouping of preferred terms (PTs) was considered for adverse drug reaction (ADR) frequency determination and includes the following: nasopharyngitis, upper respiratory tract infection, influenza, sinusitis, pharyngitis, rhinitis, viral upper respiratory infection, tonsillitis, acute sinusitis, pharyngotonsillitis, laryngitis, pharyngitis streptococcal, viral rhinitis, sinusitis bacterial, tonsillitis bacterial, viral pharyngitis, viral tonsillitis, chronic sinusitis, nasal herpes and tracheitis.1
‡‡Grouping of PTs was considered for ADR frequency determination and includes the following: urinary tract infection, cystitis, Escherichia urinary tract infection, asymptomatic bacteriuria and bacteriuria.1
§§Reported during post-marketing experience.1
¶¶Nausea and vomiting have been reported in association with systemic injection-related reactions.
‖‖Switching period refers to the participants started on teriflunomide and is not applicable to the participants on KESIMPTA in the core period. For the teriflunomide/KESIMPTA group, data from the first dose of teriflunomide until the last dose of KESIMPTA plus 100 days or analysis cut-off date has been used. R1: The first participant with first treatment-emergent assessment in KESIMPTA period after switching to KESIMPTA (72 weeks); R2: The last participant with last treatment-emergent assessment in teriflunomide period before switching to KESIMPTA (120 weeks). For all pooled analyses, a fixed value of LLN (using ALITHIOS study reference) was used: IgG: 5.65 g/L, IgM: 0.4 g/L, lymphocyte: 0.91x109/L and neutrophil: 1.96x109/L.4

ADR, adverse drug reaction; AE, adverse event; CI, confidence interval; COVID-19, coronavirus disease 2019; EAIR, exposure-adjusted incidence rate; HBcAb, hepatitis B core antibody; HBsAg, hepatitis B surface antigen; HBV, hepatitis B virus; Ig, immunoglobulin; IgE, immunoglobulin E; IgG, immunoglobulin G; IgM, immunoglobulin M; LLN, lower limit of normal; NA, not applicable; PML, progressive multifocal leukoencephalopathy; PT, preferred term; pwRMS, people with relapsing multiple sclerosis; PY, patient-year; RDTN, recently diagnosed treatment-naïve; RMS, relapsing forms of multiple sclerosis; SAE, serious adverse event; SC, subcutaneous; SE, standard error; SmPC, summary of product characteristics; TER, teriflunomide.

References

  1. KESIMPTA (ofatumumab) Summary of Product Characteristics.

  2. Hauser SL, et al. N Engl J Med 2020;383(6):546–557 and supplementary material.

  3. Pardo G, et al. P7.016. American Academy of Neurology Annual Meeting. 5–9 April 2025, San Diego, CA, US.

  4. Wiendl H, et al. P9.010. American Academy of Neurology Annual Meeting. 13–18 April 2024, Denver, CO, US.

  5. Hauser SL, et al. P804. European Committee for Treatment and Research in Multiple Sclerosis Annual Congress. 24–26 September 2025. Barcelona, Spain.

  6. Bittner S, et al. P805. European Committee for Treatment and Research in Multiple Sclerosis Annual Congress. 24–26 September 2025, Barcelona, Spain.

UK | October 2025 | 443397-1 

Adverse events should be reported. Reporting forms and information can be found at www.mhra.gov.uk/yellowcard. Adverse events should also be reported to Novartis online through the pharmacovigilance intake (PVI) tool at www.novartis.com/report, or alternatively email [email protected] or call 01276 698370.