Whether Bridge Biotherapeutics will still work on BBT-877, a treatment candidate for idiopathic pulmonary fibrosis (IPF), after the cancellation of the licensing-out deal with Boehringer Ingelheim last year is drawing attention.

BBT-877 inhibits a novel target protein activity, "autotaxin," known to be involved in fibrotic diseases.

In July 2019, Bridge Bio inked a deal with Boehringer Ingelheim to license out BBT-877 for 1.5 trillion won ($1.36 billion). In November 2020, however, Boehringer Ingelheim decided to return the investigational drug's rights to Bridge Bio due to potential toxicity concerns.

Amid the dimmed possibility of continuing R&D for BBT-877, news reports said on Wednesday that Galapagos and Gilead Science dropped the phase-3 ISABELA trial of ziritaxestat (code name: GLPG1690), the leading treatment candidate in the same drug class. Ziritaxestat is also an autotaxin inhibitor for IPF treatment.

Bridge Bio said the latest development gave BBT-877 more chance to become the first drug in the same class.

“After the discontinuation of the clinical trial of the leading candidate, the dynamics of the autotaxin inhibitor market has changed completely,” Bridge Biotherapeutics CEO Lee Jung-kue said, expressing his optimism over BBT-877.

However, observers said Bridge Bio should not take the discontinuation of the ziritaxestat’s study as a win against the leading candidate. There is a risk that the trial discontinuation might tough on the safety issue of all autotaxin inhibitors, they noted.

The trial halt was based on the Independent Data Monitoring Committee (IDMC) recommendations, which concluded that ziritaxestat’s benefit-risk profile no longer supported continuing the study. Galapagos also discontinued all trials with ziritaxestat, including the phase-2a NOVESA trial in systemic sclerosis.

“We are fully aware that the trial halt could lead to concerns over the overall autotaxin inhibitor class,” an official at Bridge Bio said. “But as the reason for the suspension of the phase-3 study of ziritaxestat has not been identified specifically, and related data is expected to be disclosed, we plan to reflect this in BBT-877 clinical development strategy.”

Bridge Bio also has to resolve the issue of the delayed phase-2 trial of BBT-877 in the U.S. Last year, the company said it would complete a Type C meeting with the FDA in the first quarter of 2021. However, it has yet to apply for a Type C meeting without any clear explanation.

A Type C meeting is a non-regular procedure, and it usually takes about 75 days to proceed after the company’s submission of the request for a meeting.

Bridge Bio said it would apply for a March meeting and hope to hold the meeting in June. Before meeting with the FDA, Bridge Bio plans to tackle potential development concerns, including BBT-877’s toxicity issues.

Thus, the company is expected to begin a phase-2 study of BBT-877 in the U.S. in the second half at the earliest.

Bridge Bio has not decided whether to license out BBT-877 or develop it on its own.

The company said it would focus on entering a phase-2 trial in the U.S. first and could not comment on a new technology transfer attempt.