Transplant Trial Watch

A Comparison of Two Types of Rabbit Antithymocyte Globulin Induction Therapy in Immunological High-Risk Kidney Recipients: A Prospective Randomized Control Study.

Burkhalter F, Schaub S, et al.

PLoS ONE 2016 [Electronic Resource] 11(11): e0165233.


Aims
To compare the safety and efficacy of two rabbit polyclonal antithymocyte globulins (ATGs) in immunological high-risk kidney transplant recipients.

Interventions
Participants were randomised to receive either induction therapy consisting of ATG-F (9 mg/kg body weight prior to reperfusion of the allograft, followed by 3 mg/kg body weight/d on day 1±4), versus induction therapy consisting of Thymoglobulin (1.5mg/kg body weight prior to reperfusion of the allograft followed by 1.5mg/kg body weight on day 1±3). Maintenance immunosuppressive therapy consisted of tacrolimus, mycophenolate mofetil and steroids.

Participants
35 kidney transplant recipients aged ≥ 18 years with a high immunological risk defined by the presence of at least one HLA donor-specific antibody (class I and/or II).

Outcomes
The primary outcomes measured were safety parameters, including the incidence of early study drug related side effects, early severe hematological side effects, adverse events and toxicity, post-transplant lymphoproliferative diseases (PTLD) and malignancy. Secondary measured outcomes included the incidence and type of rejection episodes, delayed graft function, graft function, graft and patient survival, infectious complication and effect of antithymocyte induction on peripheral T- (CD3+) and B- (CD19+) cell count.

Follow-up
2 years

CET Conclusions
This two-centre study randomised high-risk renal transplant recipients (defined as those with HLA donor-specific antibody present at the time of transplant but negative CDC crossmatch) to induction with ATG-F or Thymoglobulin. Maintenance immunosuppression comprised Tac, MMF and steroids. The authors found no difference in efficacy or safety between the two induction agents to 2 years. The main issue, as identified by the authors, is a lack of statistical power due to the small sample size (35 patients recruited over 5 years). No a priori sample size calculation was performed, and it is very likely that the resulting study is underpowered to exclude differences in either safety or efficacy. The difference in clinical rejection (35% vs 19%), whilst not statistically significant, would be of clinical significance if demonstrated in a larger sample. Therefore, the study does not answer the question that was originally posed.

Jadad score
3

Data analysis
Per protocol analysis

Allocation concealment
Yes

Trial registration
ClinicalTrials.gov - NCT00861536

Funding source
Industry funded