There is much buzz surrounding Lorcaserin in advance of 10th May, the day that the members of a key advisory panel to the Food and Drug Administration (FDA) in the USA voice their opinions on the new weight loss drug. The trade name of Lorcaserin will be Lorqess. The FDA often goes with the decision of its advisory committee but is not obliged to do so, so tomorrow will be an important day for Arena Pharmaceuticals, the pharmaceutical company behind Lorcaserin; especially as this will be the second time they will have stood before the committee attempting to get approval for this drug.
The main focus will be on the pharmaceutical company addressing the safety issues outlined by the committee the last time that Lorcaserin was considered. The concerns included fears over tumours found in rats and the potential for heart valve damage.
We are not too worried about speculation surrounding tumours that were found in rats considering the benign tumours were found in rats during clinical trials and not in humans. The benign tumours are known as fibroadenomas and among rats, are in fact very common anyway whether or not Lorcaserin is administered. Fears over the growth of tumours in humans are unnecessary and are not backed up by clinical trial evidence. We think it highly unlikely that Lorcaserin will stubble over this issue.
The risk of valvulopathy (heart valve damage) was another cause for concern. Years ago, the association between this condition and the weight loss drug fenfluramine, was the reason that the drug was taken off the market in 1997. The FDA is naturally wary, as Lorcaserin comes from the same family of molecules as Fenfluramine. The pharmaceutical company was required to carry out periodic heart scans on the patients during clinical trials to demonstrate that valvulopathy was not a concern.
The company did not observe any increase in the incidence of valvulopathy during clinical trials although the observed levels in the study population was 1.7% against a population incidence of around 2.5%. This may have an impact on the ability to meet the benchmark set by the FDA but the key observation must be the zero increase in incidences.
Possibly of greater concern will be the overall efficacy of Lorcaserin. Although it does meet the FDA’s own benchmark for weight loss drugs, the weight loss is not spectacular overall. However, some patients are high responders and the low responders can be identified at 30 days so treatment can be ceased if the response is lower than would be considered acceptable on a risk benefit analysis.
We have a feeling that Lorcaserin might just make the cut this time although we do not think that it is a sure fire winner because of the low overall response rate.