SAN DIEGO ( TheStreet) -- Thoughts, questions and reflections on Arena Pharmaceuticals ( ARNA) following Thursday's FDA advisory panel, which voted 18-4 (with one abstention) to recommend the approval of lorcaserin for weight loss. Congratulations, Arena. Well done. The company and its outside advisors did an excellent job presenting lorcaserin data to the panel. Not every argument the company made was necessarily persuasive, but it had data to back up its side. Most importantly, Arena was able to respond well to the questions and concerns raised by the experts on the panel about lorcaserin's safety -- rat tumors and cardiovascular risk, in particular. Thinking back through the live blog of Thursday's panel, I can't recall any instance where Arena was dumbstruck or intimidated by the panelists' questions. Being well prepared is a big part of emerging from the FDA panel meat grinder with a positive outcome. Which brings me to the acknowledgment that I was wrong about Arena. Going into Thursday, I was confident that the FDA panel would not recommend lorcaserin's approval mainly because the drug's efficacy is mediocre and the safety concerns insurmountable. That position was wrong, as both the FDA's internal review of lorcaserin posted last Tuesday and Thursday's 18-4 panel vote clearly demonstrated. Arena does have an approvable weight-loss drug in lorcaserin, but when? FDA final approval could come as early as June 27, the agency's official decision date. If FDA approves lorcaserin on that date, the drug will beat Vivus' ( VVUS) Qnexa as the first new weight-loss drug to reach the market in a decade. Vivus' FDA decision date is three weeks later on July 17. Don't be surprised, however, if FDA delays the lorcaserin decision by three months to Sept. 27 to give the agency and the company more time to hash out a risk management plan and final label for lorcaserin. FDA did the same thing to Vivus, which signaled the agency was willing to approve Qnexa. Vivus's stock price has traded up since the delay was announced in early April. If FDA pushes back the lorcaserin decision by three months to complete labeling and risk management plan discussions, it should be viewed positively for Arena. Delay or not, Arena looks to have an approvable weight-loss drug, but that doesn't mean lorcaserin skates through without issues. None of the late-stage obesity drugs -- lorcaserin, Qnexa or Orexigen Therapeutics' ( OREX) Contrave -- are pristine.