The HLA-DQA1*05 genotype does not influence the clinical response to ustekinumab and vedolizumab.

Background: the success of strategies with earlier anti-TNF drugs for the treatment of inflammatory bowel disease (IBD) have been shadowed by the development of anti-drug antibodies that reduce their effectiveness. The HLA-DQA1*05 allele has been shown to increase the risk of immunogenicity to anti-TNF drugs by approximately two-fold. The negative impact of this allele has not been fully investigated for newer biotherapies.

Objective: whether the presence of the HLA-DQA1*05 allele is associated with a reduction of response to ustekinumab and vedolizumab was investigated.

Material And Methods: the impact of HLA-DQA1*05 on disease activity in 93 patients with IBD, treated with ustekinumab (n = 39) or vedolizumab (n = 54) was investigated in a retrospective cohort study. Treatment response and remission was assessed at 6 and 12 months for ustekinumab, and up to 18 and 24 months for vedolizumab, using Harvey-Bradshaw index (Crohn's disease) and Mayo score (ulcerative colitis).

Results: the HLA-DQA1*05 allele was found in 35.9 % and 38.9 % of patients treated with ustekinumab and vedolizumab, respectively. Clinical response was not affected by the presence of the HLA-DQA1*05 allele for both treatment groups.

Conclusions: in contrast to anti-TNF drugs, HLA-DQA1*05 presence does not correlate with the decreased response to ustekinumab or vedolizumab.