Gilead's $5B Galapagos black hole widens as pair tosses out phase 3 asset after flop

Gilead
(Gilead China)

Gilead has sunk billions into Galapagos over the past few years, but this is quickly turning into one of the most disastrous biotech deals in recent history.

Today, the once tightly-knit pair came further apart at the seams when an independent body checked out its phase 3 data for the experimental autotaxin inhibitor ziritaxestat in patients with idiopathic pulmonary fibrosis (IPF).

The outcome was not good. Following a regular review of unblinded data, an independent monitoring board “concluded that ziritaxestat’s benefit-risk profile no longer supported continuing these studies.”

The phase 3 program, known as ISABELA, is to be canned, and so too is a phase 2 trial in systemic sclerosis, which “will be discontinued.” We don’t know the specifics of what prompted these decisions, but Gilead said it would be presenting a post-mortem data readout at a future medical meeting.

Gilead had in-licensed ex-European rights to ziritaxestat back in July 2019 and was also sharing the phase 3 costs.

“We are very disappointed not to be able to bring a novel medication to patients suffering from such a devastating disease with high unmet need,”  said Dr. Walid Abi-Saab, CMO of Galapagos.

“We would like to thank the patients and the medical professionals who participated in the ISABELA studies and contributed to the advancement of IPF research. We intend to learn from this data in our continued commitment to develop therapies in IPF and fibrosis.”

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Testicular toxicity was to blame for the FDA’s rejection of Gilead and Galapagos’ filgotinib, the centerpiece of a $5 billion boosted deal Gilead penned with the biotech in 2019 on the hope that this European company could boost its inflammation drug hopes.  

Filgotinib got approval elsewhere, but the FDA’s rejection was a stinging rebuke, also causing the companies in the fall to pause enrollment in clinical trials of filgotinib in three indications.

Gilead has now said it would give up on a U.S. approval for filgotinib in rheumatoid arthritis, pay Galapagos €160 million to take over most ongoing clinical trials and return responsibility for the drug in Europe, where it is approved.

The failure of ziritaxestat looks like another nail in the coffin for this doomed partnership, though Gilead is already shoring up its losses in this area, penning a deal to buy cancer biotech Immunomedics last year for $21 billion, a deal that so far looks a much better bet.