Vaccitech reemerges as Barinthus with hep B data showing declines in infection levels

Barinthus Biotherapeutics, recently renamed from Vaccitech, is ready to showcase its new direction. The biotech revealed some early data from a pair of trials of its hepatitis B virus therapy, showing declines in levels of infection.

In the first study, which paired Barinthus’ VTP-300 with low-dose Opdivo, the combo led to a reduction in hepatitis B surface antigen (HBsAg) in all treatment groups. HBsAg is an indication of infection with hep B. Barinthus found that patients with HBsAg levels under 200 IU/mL when they entered the trial were more likely to see stronger reductions.

The trial featured 120 total virally suppressed chronic hep B patients on stable nucleos(t)ide analogue (NUC) therapy, the standard of care. So far, 74 patients have been enrolled, with 57 reaching Day 113 and available for the data cutoff.

Seven patients met the criteria to stop NUC therapy, with three stopping and two restarting.

As for safety, early data suggest VTP-300 with Opdivo was well tolerated, and no treatment-emergent severe side effects were reported, but Barinthus did not report details. There were seven cases of thyroid dysfunction attributed to Opdivo. The condition returned to normal for four of those patients.

Barinthus will now amend the trial protocol to only include patients with screening under the HBsAg 200 IU/mL cutoff going forward, because the data suggest these patients will have the highest benefit. The biotech said this change is being made to improve the overall risk/benefit ratio. Patients with thyroid autoantibodies, family history of autoimmune thyroiditis or abnormal thyroid levels will now be excluded as well to minimize the risk of thyroiditis.

The second study tested VTP-300 in combination with Arbutus Biopharma’s imdusiran in 40 non-cirrhotic, virally suppressed chronic hep B patients on stable NUC therapy. The patients received imdusiran at first every eight weeks for 24 weeks, then received either VTP-300 or placebo at week 26 or 30. If they received a decline in HBsAg between weeks 26 and 34, they received another dose at Week 38. The patients remained on NUC therapy throughout.

Data from the patients who received the two-dose regimen from 12 out of the 40 patients were available plus follow-up data at Week 48. Barinthus said there were “robust” reductions of HBsAg when patients were receiving imdusiran. Adding VTP-300 helped maintain low HBsAg levels in the early treatment period, while the placebo group saw an increase about 12 weeks after receiving their final dose of imdusiran.

For safety, imdusiran and VTP-300 were both generally well tolerated with no serious adverse events, grade 3 or 4 adverse events or treatment discontinuations. Detailed safety data were not provided.

Arbutus signed a clinical trial collaboration with Barinthus, then known as Vaccitech, in July 2021.

The new data represent Barinthus’ new direction. The company officially renamed itself from Vaccitech earlier this week, marking the switch from a vaccine-focused biotech to one focused on T-cell immunotherapeutic aimed at chronic infectious diseases, autoimmunity and cancer. Trading began under the ticker "BRNS" Nov. 7.

“The company has evolved and expanded since being spun out of the University of Oxford. Whereas we began as a vaccine company having been involved in flu vaccines and then the co-invention and early development of Vaxzevria, the AstraZeneca/Oxford COVID-19 vaccine and the development of other prophylactic vaccines,” said CEO Bill Enright. “Today the company is focused on the development of novel T cell immunotherapeutic candidates, which evolved out of that initial vaccine research.”

Vaccitech launched in 2016 with a universal flu vaccine candidate from the University of Oxford. The biotech partnered with AstraZeneca in the early days of the COVID-19 pandemic to come up with a vaccine, which was ultimately put into use but faded after concerns of blood clots were raised.

The company managed to pull off a $110 million initial public offering at the height of the vaccine work.