Earlier this year, when Novo Nordisk’s long-acting insulin Tresiba was rejected by the FDA, it would have been hard to see any silver lining for the Danish drug maker. Novo’s stumble in the US was a gain for Sanofi’s market-leading basal insulin, Lantus. But the Tresiba setback did turn out to be a boon for Novo, just in a different franchise.

Driven by promotion originally set aside for Tresiba, Victoza sales rose by 32% year-to-date, Novo earnings show, and the company is hiking its profit forecast on those improved sales. Novo estimated that Victoza now holds 65% of the market share in GLP-1s, compared to 58% last year.

Victoza’s gain has been a loss for Bristol-Myers Squibb and AstraZeneca, which co-market rival GLP-1 drugs Byetta and Bydureon. Demand for the injectible drugs started to slip this year. with total prescriptions for the exenatide duo declining by 5% in the second quarter. AZ blamed Novo.

The Bernstein analyst Tim Anderson, in an earlier investor note, wrote, “The earlier delay of Novo Nordisk’s Tresiba caused Novo to shift promotion to Victoza which AZN suggests was one of the reasons there has been a slowdown in its GLP-1 products.”

Novo has pole position in the GLP-1 drug class, which is set to grow to $7.3 billion by 2020, according to Barclays, tempering an earlier forecast of $8.5 billion by 2020 due to a trend toward slower launches for these drugs. While Victoza continues to take share away from Bydureon, supported by promotion intended for Tresiba, Barclays analysts noted, they expect subsequent launches to compete for share rather than grow the market.

The note goes on to usher in Eli Lilly as the presumed winner of this smaller market and AZ and BMS the “relative losers.” Lilly’s dulaglutide 2020 revenue estimate is hiked from $780 million to $1.6 billion, representing a 21% value share of the GLP-1 class. As for Bydureon, Barclays lowered its 2020 forecast from $2.9 to $1.5 billion, The analysts also cut their revenue outlook for GSK’s Eperzan in half to $322 million.

Tresiba has received approval in the European Union, and is currently sold in Denmark, the UK, Switzerland, Mexico and Japan. Tresiba faces what looks like a two-year delay for entry in the US as FDA is requiring a new study to evaluate possible heart risks. Novo expects to begin this trial by the end of the year.