Arena Pharmaceuticals, Inc. Earnings: Explaining the Wonky Trends

Another quarterly earnings report, another loss for Arena Pharmaceuticals . The obesity-drug maker lost $32 million in the fourth quarter, bringing up the total loss for the year to a little over $60 million.

Not that the magnitude of the loss matters much, the trajectory of the launch of Belviq is much more important.

Source: Area Pharmaceutical press releases.

Two obvious things stick out in the chart: a slowdown of quarter-over-quarter growth in the fourth quarter and relatively flat net sales despite a doubling of prescriptions from the first quarter to the fourth quarter.

Both are fairly easy to explain.

Turkey trumps pillsThe obesity-drug market is one of the few drug markets that's seasonal and typically declines in the fourth quarter. Who wants to diet over the holidays? (Yes, you have to diet while on Belviq or one of the other obesity drugs to see reasonable weight loss; these aren't wonder drugs.)

Arena Pharmaceuticals claims the obesity-drug market contracted 4% between the third quarter and the fourth quarter, so a 4% increase in prescriptions sounds like a win to me.

You can give this stuff awayPart of the slow launch of Belviq has to do with the lack of insurance coverage for the drug. And when insurers cover the drug, it's often placed on the highest tier, requiring high copays. Many people may want to lose weight, but only a small percentage of them want to shell out $100 or more a month to do it.

To capture patients with insurance that doesn't cover Belviq and encourage patients that are covered by insurance to use the drug, Arena's marketing partner, Eisai, instituted a prescription savings card that allows cash-paying patients to only pay $75 per month and patients with insurance that covers Belviq to get $75 off each prescription after they pay the first $50 copay each month.

Add in samples and a program that allows patients to get their first 15 days for free, and gross to net adjustment increased to 47% last year. In other words, the average patient is only paying about half the list price of the drug. Given that's the average for the year and the flat sales throughout, the fourth quarter was presumably higher.

Unfortunately for Arena, its 31.5% manufacturing and royalty rate is based on the net sales, so those discounts hurt the revenue line. In the fourth quarter, Arena earned just $3.8 million off sales by Eisai.

Accelerating salesOffering discounts now can work out in the long run if those cash-paying patients eventually have a higher price tag because their insurance starts covering Belviq.

Perhaps more importantly, the discounted sales now could turn into more prescriptions later if doctors see that patients lose some weight and don't experience any side effects. The other half of the slow start has to do with convincing doctors to use drugs to treat obesity after multiple drugs have been pulled off the market because of side effects not recognized during the clinical trials.

The launch of Orexigen's Contrave by its marketing partner Takeda and Novo Nordisk's Saxendashould help in that vein. Sure, some patients that would go on Belviq will end up on those drugs, but the sales people talking to doctors about treating obesity with drugs will have a positive effect on the obesity drug market as doctors open up to the idea of treating obesity with drugs.

If things go really well, we could even see a quarter-over-quarter increase in the fourth quarter of this year.

The article Arena Pharmaceuticals, Inc. Earnings: Explaining the Wonky Trends originally appeared on Fool.com.

Brian Orelliprefersthe drumstick over the breast even though he knows it isn't good for him. He and The Motley Fool have no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.