Arena Pharmaceuticals (NASDAQ:ARNA) held a press conference in conjunction with its second-quarter earnings to let investors know what's happening with its obesity drug Belviq and the rest of its pipeline. Below, you'll find five quotes from the call that highlight the most pressing issues at the biotech.

Jack Lief. Source: Arena Pharmaceuticals.

1. "Since the initiation of direct-to-consumer television advertisements in mid-April, new Belviq prescribers have increased from approximately 800 per week to approximately 1,200 per week." -- Jack Lief, Arena's co-founder, chairman, CEO and president

Arena's marketing partner Eisai can reach a lot more doctors by having patients ask their doctors to prescribe a drug they heard about on television. While the commercials appear to be working -- a 50% increase in new prescribers is nothing to sneeze at -- it's important that those new prescribers make a second and third and one hundredth prescription as well. If they're only going to prescribe Belviq for patients who ask about the drug, it's going to be very costly to acquire new patients.

2. "In the second quarter, more than 110,000 prescriptions were filled an increased 43% over the previous quarter, and we have recently seen estimated total prescriptions surpass 10,000 per week milestone." -- Lief

Sounds good, right? Unfortunately Eisai is working off such a small base that a 43% increase doesn't account for much, especially since management noted that a "good percentage" of the increase was for free trials; Eisai only booked $9.9 million in net product sales of which Arena Pharmaceuticals was due a measly $3.1 million.

Craig Audet. Source: Arena Pharmaceuticals.

3. "In June, our 12-week phase 2 proof-of-concept trial to evaluate lorcaserin as an aid to smoking cessation, met its enrollment target of at least 600 patients, and we expect to have results for this study around the end of the year." -- Craig Michael Audet, senior vice president of operations and head of global regulatory affairs at Arena.

Lorcaserin is the active ingredient in Belviq, which works by stimulating a receptor called 5-HT2 receptor family, which makes people feel sedated, among other things. The same sedated feeling that causes overweight patient to not be interested in eating should also make smokers uninterested in cigarettes.

Patients might also lose weight while taking lorcaserin to stop smoking, but that wouldn't necessarily be a bad thing, since people often gain weight when they're trying to quit by substituting the happy feeling they get from smoking with the happy feeling they get from eating.

Investors should keep an eye on this trial as Eisai will have a much easier time marketing lorcaserin as a smoking cessation drug than as an obesity treatment. Eisai and VIVUS (NASDAQ:VVUS), which also has an obesity drug, have had to convince doctors that obesity is a disease that really needs to be treated with drugs. No one needs to be convinced that smoking is bad for you.

4. "The 12-week pilot study of the co-administration of lorcaserin and phentermine also met its enrollment target of at least 225 patients earlier this year. And we expect to have these results around the end of the year as well." -- Audet

Belviq works in a similar way to fenfluramine, the ingredient fen-phen that caused the heart valve problems, but Belviq appears to not cause the side effects that fenfluramine caused. It only makes sense to combine Belviq with phentermine, the phen in fen-phen.

While lor-phen doesn't have doesn't have the same ring, it should produce more weight loss than Belviq alone without the fen-phen side effect. Since the study is small and only 12 weeks long, investors should be looking for an efficacy signal; a statistically significant improvement over Belviq alone isn't necessarily needed to justify moving on. Arena will have to run a phase 3 trial to test efficacy over a year and to confirm there aren't any heart problems with the combination.

5. "Before opening the call to questions, I'd like to discuss my recent sale of Arena stock, which occurred under what is commonly referred to as a 10b5-1 trading plan. Such plans are used to automatically sell stock at a future date. The timing of the stock sale was set when I established the trading plan about a year ago, shortly after the launch of BELVIQ, and the sale was intended to provide some diversification." -- Lief

You certainly can't fault Lief for wanting a little diversification, but the sale seems like a sign that he doesn't think shares are going to go up anytime soon.

Brian Orelli 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.