Biogen CFO Paul Clancy told investors that a recently launched DTC campaign for multiple-sclerosis drug Tecfidera is showing “positive leading indicators,” including increased hits to the drug’s website and higher call volume to its patient services organization.

The full impact of the campaign has not yet been assessed, Biogen CEO George Scangos cautioned during the company’s full-year earnings call Wednesday, noting that a full analysis would come after the first quarter of 2016 but did concede that the early data is positive.

“While we’re hopeful our recently launched marketing campaign can reaccelerate growth [for Tecfidera],” Scangos said, “we remain cautious, as we believe we will not ascertain the impact until the second quarter of this year.”

See also: Biogen, PatientsLikeMe use Fitbit to better understand MS

The campaign, which debuted in October, asked viewers to take “another look” at relapsing multiple sclerosis, showing a woman living her life with fewer relapses—including shots of her hiking, swimming and attending a carnival. Biogen spent nearly $24 million on the TV spot from October 5 through the end of January, according to estimates from iSpot.tv. It is expected to run well into 2016. At the time of the campaign’s announcement, the drugmaker also announced it would cut its workforce by 11%—a reduction that will affect more than 800 employees.

These remarks come as the drug enjoyed its most lucrative quarter ever. For the last three months of 2015, Tecfidera reined in $993 million in global sales, compared to $916 million in the same period a year ago. Overall, Tecfidera brought in $3.6 billion last year—$2.9 billion of which was from the US. The drug’s total sales were $2.8 billion in 2014. Tecfidera is the most commonly prescribed oral MS drug.

Those lofty sales may have also been spurred by a recent price increase. When Tecfidera first launched in April 2013 it was priced at $54,9000 per year. The drug now costs $70,614 over the same time period—a 28% increase over the past two years. The drugmaker’s executives told investors that it increased the price during the third quarter of 2015.