Allergan, And Linzess' Misleading Side Effects
Life Sciences MillennialSep. 20, 2017 12:33 PM ET
Allergan allowing Linzess patients to have their dose reduced in their initial trials, unlike Synergy's Trulance, has resulted in misleading side effects.
The Linzess 72mcg dosing trial did not allow dose reductions, which proved my theory that Linzess is producing even higher diarrhea than originally thought.
Original Linzess trials, including the 27% of dose reductions, showed diarrhea of 16%, while not allowing the dose reductions showed a worsening 22%.
Synergy's Trulance has captured 13.3% market share in CIC, with no DTC campaign and 5x less of a salesforce, while being on the market for less than 6 months.
Synergy's Trulance is surpassing Linzess (72mcg) in market share, while Takeda's Amitiza has lost 10% in market share since Trulance's launch.
Over the course of the last several months, I have been very vocal about the chronic idiopathic constipation (CIC) and irritable bowel syndrome with constipation (IBS-C) spaces. With this latest article, I hope to bring emphasis to a subtle difference seen in the trials for Linzess, a drug marketed by both Allergan (NYSE:
AGN) and Ironwood Pharmaceuticals (NASDAQ:
IRWD). This subtle difference I think is providing misleading side effects as it relates to Allergan's Linzess.
This subtle difference is something I had touched on earlier in another article of mine, seen
here. The specific portion that I am referencing from my past article is also below:
Patient disruptions/interruptions were not allowed in Trulance studies, but were allowed in Linzess studies. Meaning, the percentage rate of adverse events for Linzess could have been much higher if patients weren't allowed to have their treatment disrupted.
When I mention, "patient disruptions/interruptions", I am referring to the 27% of Linzess patients who had their dosing reduced because of adverse events. Adverse events meaning diarrhea. The 27% of Linzess patients who had their dosing reduced was seen in the original Linzess studies ran long ago for their 145mcg and 290mcg doses. With patients being allowed to have their doses reduced, Allergan and Ironwood claimed that patients experienced diarrhea of 16% in these trials. The Linzess drug
label can be seen here, along with a graphic displaying the 27% of patients who had their dosing reduced.
The important item to remember is that Trulance, marketed by Synergy Pharmaceuticals (NASDAQ:
SGYP), did
not allow patients to have their dosing reduced because of adverse reactions. Therefore, the 16% of patients who had diarrhea with Linzess
most likely would have experienced
higher diarrhea if they were
not allowed to have their dose reduced. The best way to test my theory would be by looking at Linzess' new 72mcg dose trial, which did not allow for interruptions. That trial can be seen below:
The results of the 72mcg dosing trial (Trial 5), proved that my theory carries some weight. As you can see in the 72mcg trial, which did not allow for interruptions, the diarrhea rate for the 145mcg dose was worse off than what was originally thought (16% to now 22%). The diarrhea rate for the 72mcg dose is 19%. All of these rates are no comparison to the less than 5% of diarrhea seen in Trulance patients. Again, no patients were ever allowed to have their dose reduced in Trulance
studies, which would make a comparison to the Linzess 72mcg trial more accurate.
NOTE: When looking at the Trulance and Linzess labels, don't get confused with "adverse reactions leading to discontinuation". This is a totally different metric and is unrelated to "adverse reactions leading to dose reductions", which is only on the Linzess label.
Also, to my likely critics, notice that the sample size in trial 5, the 72mcg dose trial, is nearly the same size as the original trials that were run. Therefore, the argument that the last Linzess trial was producing worse diarrhea because it was a smaller sample size carries little weight. The drug is producing worse diarrhea because patients were denied the ability to have their treatment interrupted.
Allergan's results from the Linzess 72mcg dose trial are a more accurate depiction of the drug's ability to produce significant diarrhea. Synergy's Trulance no longer has a 5% diarrhea vs. 16% diarrhea advantage against Linzess. It is more like 5% vs. 22%, which should further distinguish Trulance as the best in class treatment in this category.
When Synergy first released their Phase 3 data, it was stated by analysts that Synergy would have to produce less than 10% diarrhea to have an impact on or surpass Linzess eventually. With a 22% vs. 5% advantage now, Trulance is well on their way. In less than six months, Amitiza, marketed by Takeda, has
lost 10% market share already. By this time next year, Amitiza probably would be dropping another 10%, which should start putting severe pressure on Takeda, if not already. Synergy has not even started their DTC campaign yet, and the company is not even approved for IBS-C. The approval for IBS-C in January, and the launch of Synergy's DTC campaign, are the weapons that will be used to capture market share away from Linzess.
Allergan's Linzess franchise should start feeling the heat next year from Trulance. Synergy also has a 250 person salesforce compared to 1,400 with Allergan. A potential buyout of Synergy from another big pharma company will put severe pressure on Allergan's plans against Trulance, as they're essentially increasing their salesforce substantially overnight.