Patients treated with KYGEVVI were compared to an external control group of untreated patients.1,2

The survival analysis included 78 patients treated with KYGEVVI with a median age of TK2d symptom onset at 1.5 years (range: 0.01-12 years).1

  • The efficacy of KYGEVVI for the treatment of patients with TK2d, with an age of symptom onset ≤12 years of age, was established based on data from:1
    • One Phase 2, prospective, open-label, single-arm study (Trial 1)1
    • Two retrospective chart review studies (Study 1, Study 2)1
    • Expanded access program1
  • The survival in treated patients was compared with survival in an untreated external control group comprised of untreated patients from published literature and Study 21
  • The untreated patients were matched to the treated patients using age of TK2d symptom onset (≤2 years or >2 years to ≤12 years)1
  • A total of 78 matched pairs were identified1

Baseline characteristics of treated patients with TK2d onset at ≤12 years old1

Study Population

KYGEVVI (n=78)

Male, % (n)

54% (42)

Median treatment duration, years

4 (range: 1 day to 12 years)

Median dose, mg/kg/day

762 (range: 260 to 800 mg/kg/day)

EARLY-ONSET TK2d IS A LIFE-THREATENING DISEASE.3

Overall survival time with KYGEVVI was studied.1

View the data  

References

  1. KYGEVVI (doxecitine and doxribtimine) U.S. Prescribing Information. Smyrna, GA: UCB, Inc.
  2. Hirano M, Garone C, Haas R, et al. Survival analyses in patients with thymidine kinase 2 deficiency aged ≤12 years at symptom onset who received pyrimidine nucleos(t)ide therapy. Poster presented at: MDA Clinical and Scientific Conference; March 16-19, 2025; Dallas, TX, virtual.
  3. Garone C, Taylor RW, Nascimento A, et al. Retrospective natural history of thymidine kinase 2 deficiency. J Med Genet. 2018;55(8):515-521. doi:10.1136/jmedgenet-2017-105012

INDICATION

KYGEVVI is indicated for the treatment of thymidine kinase 2 deficiency (TK2d) in adults and pediatric patients with an age of symptom onset on or before 12 years.

IMPORTANT SAFETY INFORMATION

Increase in Liver Transaminases

Elevated liver transaminase [alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST)] levels were reported in patients treated with KYGEVVI. Obtain baseline liver transaminase (ALT, AST) and total bilirubin levels in patients prior to treatment initiation with KYGEVVI.

INDICATION

KYGEVVI is indicated for the treatment of thymidine kinase 2 deficiency (TK2d) in adults and pediatric patients with an age of symptom onset on or before 12 years.

IMPORTANT SAFETY INFORMATION

Increase in Liver Transaminases

Elevated liver transaminase [alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST)] levels were reported in patients treated with KYGEVVI. Obtain baseline liver transaminase (ALT, AST) and total bilirubin levels in patients prior to treatment initiation with KYGEVVI. If signs or symptoms consistent with liver injury are observed, interrupt treatment with KYGEVVI until liver transaminase (ALT, AST) and total bilirubin levels have either returned to baseline or stabilized at a new baseline value. Consider permanently discontinuing KYGEVVI if signs or symptoms consistent with liver injury persist or worsen. Monitor liver transaminases and total bilirubin levels yearly and as clinically indicated.

Gastrointestinal Adverse Reactions 

Diarrhea and vomiting leading to hospitalization, dose reduction, and permanent discontinuation were reported in patients treated with KYGEVVI. Based on the severity of the diarrhea and/or vomiting, reduce the dosage of KYGEVVI or interrupt treatment until diarrhea and/or vomiting improves or returns to baseline. Consider restarting KYGEVVI at the last tolerated dose, and increase the dose as tolerated. For persistent or recurring diarrhea and/or vomiting, consider discontinuing KYGEVVI permanently and provide supportive care with electrolyte repletion as clinically indicated.

Adverse Reactions

The most common adverse reactions (incidence ≥5%) are diarrhea, abdominal pain (including abdominal pain upper), vomiting, alanine aminotransferase increased (ALT), and aspartate aminotransferase increased (AST).

Please see the full Prescribing Information.