Merck’s Keytruda and Bristol-Myers Squibb’s Opdivo, for all their similarities, have taken markedly different commercial strategies to selling their immuno-oncology drugs.

Merck has spent more than double what Bristol-Myers Squibb has spent on Opdivo to promote Keytruda in professional journals targeting doctors. BMS has chosen a different route, electing to make huge splashes in direct-to-consumer advertising.

In the first half of 2016, Keytruda was the thirteenth most advertised brand in professional journals, with Merck doling out more than $2 million to target doctors, according to Kantar Media. During the same time period, Opdivo didn’t even break into the top 20 of advertised pharmaceutical brands — Bristol-Myers Squibb spent $863,000 on professional ads for the drug, significantly less than what Merck spent.  

But that’s not to say BMS hasn’t promoted Opdivo. The company spent $37 million on DTC ads in the first quarter of 2016 and a total of $125 million advertising the therapy in 2015, while Merck spent only $7.3 million in DTC spending over the same time period. In fact, Bristol-Myers Squibb promoted the drug directly to consumers to such an extent that it came under fire from investors last year.

An agency executive interviewed for this story said that “what you’re seeing is two different strategies based on market position. Opdivo is getting the bulk of its business in second-line, and they lacked awareness of a hopeful treatment. I think it made sense for them to spend the money [on DTC].”

Merck did not respond to requests for comment by press time. 

See also: Pro ad report: All the data on journal spending in 1H 2016

The different tactics these companies have used thus far may dictate what their future marketing plans will look like as Merck near its FDA decision dates for treatment in first-line lung cancer, a decision that is expected to level the playing field between the two drugs. Keytruda is expected to go before the FDA on December 24.

Deutsche Bank analyst Gregg Gilbert in January questioned the use of DTC as a tactic to promote Opdivo in second-line lung cancer during a Bristol-Myers Squibb earnings call, saying that adoption of immuno-oncology drugs was likely to grow regardless of whether or not the company promoted it directly to patients.

BMS CEO Giovanni Caforio responded by defending the ad, Longer Life, saying the company wanted to dispel pessimism about oncology therapies that lack “significant value.”

Credit Suisse analyst Vamil Divan defended the company’s strategy, saying last week that “Bristol saw a need to do DTC, and they saw decent returns in terms of uptake by people coming to see their doctor. They knew they were going to be the market leader with their label and that drove them to be aggressive.”

That strategy may have lead Opdivo to significantly higher sales. Opdivo brought in $942 million in 2015, compared to Keytruda’s $566 million during the same year.

See also: Opdivo bet backfires, creates opening for Merck to pursue DTC

While BMS has seen success with DTC so far, now it may make less sense for the drugmaker going forward, Divan said. “The leader does more DTC advertising,” he added. “They want to bring patients in, but if you’re the third or fourth best product, [patients] might not get your drug if someone else has 75% market share.”

Opdivo recently suffered a development setback in the bid for a front-line indication when the drug missed its primary endpoint in a Phase-III trial in August. Merck, on the other hand, is expected to hear from the FDA by December 24 about whether Keytruda as a monotherapy will be approved as a front-line treatment.

See also: BMS CEO defends use of DTC to promote cancer drug

The same agency executive said he doesn’t expect to see Merck make huge outlays for DTC if it scores that first-line approval. “I don’t know that they need it,” he noted. “BMS needed [DTC] to make second-line patients aware and excited. Front line is different. Everyone gets there. However, I wouldn’t put it past [Merck] to do a major PR play.”

Divan believes that a Keytruda approval in the first-line may cause Bristol-Myers Squibb to change its strategy. “I don’t see how it would benefit BMS in lung,” he said. “Most of [the market] share would go to Merck. They would just be helping their competitor.”