Vanda's PhII data offer hope for gastroparesis patients who have seen no new treatments in decades
As one of the handful of drugs-in-development for gastroparesis, Vanda Pharmaceuticals’ $VNDA tradipitant has set itself apart for the condition that affects about 6 million in the United States and has not seen an approval in nearly four decades. On Monday, the drugmaker released mid-stage data that impressed, showing the drug conferred a statistically significant improvement in nausea symptoms and nausea-free days.
Gastroparesis is a chronic condition with few treatment options that affects the normal spontaneous movement of the muscles in the stomach, which usually propel food through the digestive tract. In patients afflicted with the condition, these muscles work poorly or not at all, delaying or preventing the stomach from emptying, causing nausea, vomiting and issues with blood sugar levels and nutrition. The etiology of gastroparesis is unclear, but the condition sometimes presents as a complication of diabetes or surgery. The one FDA-approved drug specifically sanctioned for use in gastroparesis is metoclopramide, which carries a black box warning that cautions against prescribing for longer than 12 weeks.
Vanda’s drug, a neurokinin-1 receptor (NK-1R) antagonist that was licensed from Lilly $LLY in 2012, was tested against a placebo in idiopathic and diabetic gastroparesis patients in the month long Phase II study. The drug met the main goal, as well as a number of key secondary endpoints, and was well tolerated with a safety profile similar to that of the placebo.
“Tradipitant could offer a much more tolerable, chronic treatment, and given the paucity of programs in development for this indication (we count ~4 others), we believe this asset could garner interest form potential partners. We think this point will become a debate among investors on whether VNDA should partner this program based on the Phase 2 data or proceed into Phase 3, with the latter being the strategy currently being pursued by the company,” Stifel analysts wrote in a note.
The trial hit the primary endpoint of nausea improvement as measured by patient diaries that rated their symptoms on a 0-5 scale. Patients on tradipitant reported a drop of 1.2 versus a fall of 0.7 on placebo (p=0.0099). For nausea-free days, another critical endpoint, tradipitant brought about a roughly 29% increase, compared to about 15% for patients receiving placebo. Improvements were also seen in most of the core gastroparesis symptoms including vomiting, bloating, and fullness after meals — most effects were apparent by the second week of treatment although improvements continued through the fourth and last week of treatment in the tradipitant group, the company reported.
“Based on our previous KOL checks, a ≥1 improvement on nausea and ≥20% improvement on nausea free days was viewed as clinically meaningful, and we believe tradipitant has met this hurdle in the more severe patients, which made up the majority of the study population. Importantly, there were improvements/no worsening on the other core symptoms of gastroparesis, which is important from an FDA perspective based on the agency’s 2015 draft guidance,” Stifel analysts added.
Tradipitant is expected to rake in peak sales of 898 million, estimated Jefferies analysts. Meanwhile, analysts at Stifel said they had raised their peak sales expectations from $535 million to $800 million, noting that their updated forecast could still be conservative, “given the size of the market and the fact over ~3-4 million scripts are written each year for metoclopramide”.
The drug is currently also being tested in a late-stage study in atopic dermatitis associated chronic pruritus, after a mid-stage study yielded mixed data in the condition.