MannKind’s inhaled insulin drug Afrezza contributed €1 million ($1.1 million) to French drugmaker Sanofi’s first-quarter sales. Sanofi said that sales of its flagship diabetes drug Lantus fell 5% to €1.58 billion during the quarter. Last year, Sanofi signed a deal with MannKind to sell its inhaled insulin product Afrezza. The drug officially went for sale in the U.S. in early February.

MannKind Afrezza

MannKind likely to miss Afrezza sales estimates

Afrezza sales figures revealed by Sanofi presumably include inventory stocking. Analysts on average were expecting MannKind to generate $3 million to $4 million in Afrezza sales in the first quarter. Sales figures released by Sanofi are disappointing. However, the sales miss did not come as a huge surprise because data compiled by IMS Health had already pointed to weak prescription numbers.

At this point, Afrezza sales are not financially material to Sanofi’s Q1 results. But its long-term success would give the French company some breathing room as its best-selling diabetes drug Lantus is set to go off-patent this year. Citing data from IMS Health, RBC Capital Markets warned earlier this month that Afrezza could miss sales estimates.

Based on the prescriptions tracked by IMS Health, Afrezza sales were about $250,000 in the first quarter. That figure excludes any free samples provided to patients, and inventory stocking. Investors will get a clear pictur when MannKind reports its quarterly results in May. Investors will be laser focused on MannKind’s Afrezza sales because its success could pay off handsomely.

MannKind, Sanofi building awareness about the product

A Sanofi spokeswoman said that the initial rollout of Afrezza was “targeted and focused” on building awareness about the product and appropriate usage. It will take time for the drug to demonstrate its potential. MannKind and Sanofi plan to launch a direct-to-consumer campaign this year. The U.S. company is also tripling production capacity at its Danbury plant. MannKind will launch the 12-unit cartridge in the second half of this year to complement the 4-unit and 8-unit cartridges.

MannKind shares fell 2.84% to $4.45 at 10:15 AM EDT on Thursday.