MannKind stock began to rally this morning in premarket trading after hitting its lowest level since June 9 after hitting a double top the day before. Shares climbed as much as 2% in premarket trading this morning before reversing yet again, suggesting that another difficult day is on tap today.

As of this writing, shares of MannKind were trading at $4.82 per share.

MannKind

Why MannKind shares are struggling

Perhaps one of the issues on Monday was the latest set of data regarding Afrezza prescription numbers. They were flat to down compared to the previous week, indicating that MannKind is not growing its numbers at all and may not be able to achieve bullish estimates.

Also management made some comments on June 10 that they’re “not there yet” on their efforts with Afrezza sales. Those comments have been weighing on MannKind shares since Chief Financial Officer Matthew Pfeffer made them.

MannKind’s Afrezza struggles to gain share

RBC Capital Markets analyst Adnan Butt reported for the week ending July 17, MannKind collected a total of 386 prescriptions for Afrezza, which was flat with the previous week. The four-week moving average for total prescriptions increased to 382. There were 262 new prescriptions, which was a 3.7% decline from the previous week’s 272 new scripts. The four-week moving average moves up to 259.

Afrezza held 0.11% of the insulin market, which was flat with the previous week. Meanwhile Apidra increased its share from 2.88% the previous week to 2.95%. Humalog’s share also increased from 40.29% to 40.51%, as did Novolog’s share, which rose from 46.2% to 46.23%.

How much Afrezza will MannKind sell?

Butt estimates that this year so far, MannKind has recorded about $1 million worth of Afrezza sales. That’s based on a cumulative total prescription number of 5,560 and an assumed price of between $158 and $1.95. He said if the inhaled insulin maker is going to reach his total 2015 sales estimate of $5.1 million, it must achieve a 7% week over week growth rate in prescriptions. That’s an increase from the previous 6.5% required the previous week.

The analyst notes that MannKind’s marketing partner, Sanofi, reported about $1.1 million in sales of Afrezza during the first quarter. He also pointed out that it’s not clear just how much inventory contributed or whether handing out samples had any impact. When Sanofi reports sales numbers for the second quarter, we should get a clearer picture on demand and sales for the inhaled insulin. Sanofi’s next earnings call on details about Afrezza is scheduled for July 30 at 8:30 a.m. Eastern.