Deucravacitinib is important to Bristol Myers for several reasons.

The drug is seen as a potential top-seller, leading a new class of oral drugs that could challenge the injectable biologics used by millions of patients with different autoimmune diseases.

Deucravacitinib could also soften the blow of losing Otezla, an anti-inflammatory medicine Bristol Myers was forced to sell as part of its acquisition of Celgene in 2019. Additionally, the drug is a key component of Bristol Myers’ plan to replace the revenue that will disappear when Eliquis, the company’s blockbuster blood thinner, loses patent protection in a few years. Bristol Myers expects deucravacitinib to generate more than $4 billion in annual sales — a little less than half of Eliquis’ 2020 total — by the end of the decade.

The drug already passed its first big test, succeeding in Phase 3 trials in psoriasis and beating Otezla head-to-head. That result should get deucravacitinib to market, paving the way for TYK2 inhibitors from Pfizer, Nimbus Therapeutics, Galapagos and others. Bristol Myers plans to launch the drug in 2022, pending approval.

Deucravacitinib “has the potential to be the oral agent of choice,” said CEO Giovanni Caforio, on a conference call in April. (The pharma also has an exclusive option to license Nimbus’ drug.)

But the broader promise of deucravacitinib, as well as others in the closely watched TYK2 class, is unclear. Though Bristol Myers has pitched the drug as a more convenient alternative to injectable drugs, its efficacy results in psoriasis weren’t as strong as some other medicines. And while the drug’s safety profile has encouraged, TYK2 blockers work by inhibiting a protein that’s a close cousin of a family of proteins called JAKs. Several approved medicines that target JAKs are now under regulatory scrutiny due to their association with blood clots and other safety problems.

Much will depend on how deucravacitinib performs against several diseases, not just one. That makes its failure in ulcerative colitis — the first disease beyond psoriasis in which the drug has results — a notable setback. Bristol Myers didn’t provide specifics in its press release beyond disclosing that the drug didn’t hit any of its study goals and that no new safety signals were identified.

But Bristol Myers does have a chance to bounce back, with a second study called IM011-127 underway and evaluating a higher dose. Data could come in 2022, according to clinicaltrials.gov.

Mid-stage trials in Crohn’s disease and lupus are also ongoing, as is a Phase 3 study in psoriatic arthritis. All of them should produce results next year or in 2023. Bristol Myers is planning more as well, executives indicated on the April conference call.