Background: Seven weeks of high-dose vitamin D treatment decreases intestinal IL17A and IFN-γ mRNA expression in active Crohn’s disease (CD). In this follow-up study, we investigated whether seven-week vitamin D treatment affected the infliximab response in the following 45 weeks compared to placebo. Methods: CD patients (n = 40) were initially randomised into four groups: infliximab + vitamin-D; infliximab + placebo-vitamin-D; placebo-infliximab + vitamin-D; and placebo-infliximab + placebo-vitamin-D. Infliximab (5 mg/kg) or placebo-infliximab was administered at weeks 0, 2 and 6. Vitamin D (5 mg bolus followed by 0.5 mg/day for 7 weeks) or placebo-vitamin D was handed out. After the 7-week vitamin D period, all patients received infliximab during follow-up. Results are reported for Group D+ (infliximab + vitamin-D and placebo-infliximab + vitamin-D) and Group D- (infliximab + placebo-vitamin-D and placebo-infliximab + placebo-vitamin-D). Results: Group D- patients had greater needs for infliximab dose escalation during follow-up compared to group D+ (p = 0.05). Group D+ had lower median calprotectin levels week 15 (p = 0.02) and week 23 (p = 0.04) compared to group D-. Throughout follow-up, group D+ had 2.2 times (95% CI: 1.1–4.3) (p = 0.02) lower median CRP levels compared with group D-. Conclusions: Seven weeks high-dose vitamin D treatment reduces the need for later infliximab dose-escalation and reduces inflammatory markers. EudraCT no. 2013-000971-34.

Background: Vitamin D treatment may reduce Crohn’s disease (CD) activity by modulating the mucosal immune function. We investigated if high-dose vitamin D +/− infliximab modulated the mucosal cytokine expression in active CD. Methods: Forty CD patients were randomized into: infliximab + vitamin D; infliximab + placebo-vitamin D; placebo-infliximab + vitamin D or placebo-infliximab + placebo-vitamin D. Infliximab (5 mg/kg) and placebo-infliximab were administered at weeks 0, 2 and 6. Oral vitamin D was administered as bolus 200,000 international units (IU) per week 0 followed by 20,000 IU/day for 7 weeks or placebo. Endoscopy with biopsies was performed at weeks 0 and 7 where endoscopic activity was measured and mucosal mRNA cytokine expression was examined. C-reactive protein (CRP), fecal calprotectin and Harvey-Bradshaw Index (HBI) were measured at weeks 0, 2 and 6. Results: High-dose vitamin D treatment alone and combined with infliximab decreased the IL17A, IFNγ and IL10 expression. High-dose vitamin D alone did not significantly decrease the disease activity, CRP or calprotectin. Combined infliximab and vitamin D treatment was not clinically significantly superior to monotherapy with infliximab. Conclusions: High-dose vitamin D as monotherapy and combined with infliximab decreases IL17A, IFNγ and IL-10 expression in mucosa within treatment groups. This did not induce a statistically significant decreased disease activity. EudraCT no.2013-000971-34.

Introduction Immune checkpoint inhibitors (ICI) have revolutionized the treatment of metastatic malignant melanoma (MM) and improved long-term survival. Despite the impressive results, some patients still have progressive disease, and the search for biomarkers predicting response to ICI treatment is ongoing. In this search, galectin-3 (Gal-3) has been suggested as a molecule of interest, both as a marker of treatment response and as a treatment target to potentiate ICI therapy. We have previously demonstrated the binding between programmed cell death 1 (PD-1) and Gal-3, and here, we investigated the interaction between PD-1, pembrolizumab, and Gal-3 in metastatic MM patients. Methods The binding between PD-1, pembrolizumab and Gal-3 was investigated by surface plasmon resonance (SPR) and cryogenic electron microscopy (cryo-EM). The function was studied in in vitro cultures and soluble levels of both PD-1 and Gal-3 were measured in metastatic MM patients, treated with pembrolizumab. Results By SPR, we demonstrated that Gal-3 can block the binding between PD-1 and pembrolizumab, and further visualized a steric inhibition using cryo-EM. T cells cultured with Gal-3 had reduced pro-inflammatory cytokine production, which could not be rescued by pembrolizumab. In patients with metastatic MM, high levels of Gal-3 in plasma were found in patients with a longer progression-free survival in the study period, whereas high Gal-3 expression in the tumor was seen in patients with disease progression. Soluble PD-1 levels in plasma increased after treatment with pembrolizumab and correlated with disease progression. Conclusion We demonstrate that the interaction between PD-1 and Gal-3 interferes with the binding of pembrolizumab, supporting that an immune suppression induced by Gal-3 in the tumor microenvironment cannot be rescued by pembrolizumab.