Applied Molecular Transport's UC drug hits roadblock after proving less effective than Humira

Applied Molecular Transport’s stock crashed down to earth this morning as the biotech’s inflammatory bowel disease drug failed to beat AbbVie's Humira in a phase 2 trial in ulcerative colitis.

A combination of a 3 mg daily dose of the drug, AMT-101, with an injection of Humira proved less effective than Humira and placebo at causing clinical remission after eight weeks of treatment in 49 patients with moderate-to-severe UC. In fact, overall remission rates for patients taking the drug combo were 31.8%, compared to 33.3% in the placebo cohort.

Although the company pointed to a subgroup analysis to show the drug combo is most effective in patients in the earlier stages of the disease, the news still caused AMT’s shares to plunge 22% to $2.45 by 11 a.m. ET on Wednesday morning.

A dive into different patient group data revealed a significant divide between the effectiveness of the treatment depending on how long patients had suffered from UC. For the cohort who had experienced the disease for five or more years, none of those who received the AMT-101-Humira combo saw remission, compared to half of those who took Humira and placebo.

Yet this ratio was reversed among patients who had the condition for less than five years, with 43.8% of those receiving the drug combo seeing a remission, compared to just 15.4% of those in the Humira-placebo cohort.

Adverse events were mostly mild to moderate, with the only serious adverse event—worsening of UC—deemed to be unrelated to the treatment.

“While the clinical remission rates for combination therapy surpassed previous anti-TNFα monotherapy and UC clinical remission benchmarks, we did not anticipate the high rate of remission in the adalimumab-alone arm,” AMT Chief Medical Officer Bittoo Kanwar, M.D., said in a statement.

“The observation of an unequal duration of UC between the trial arms led us to perform a post hoc sub-group analysis which supports additive efficacy with the combination in patients earlier in their course of UC,” Kanwar said.

These data will inform the biotech’s future development plans for AMT-101 as a combination therapy and the company plans to discuss the next steps with the FDA, he added.

AMT has a number of irons in the fire when it comes to its inflammatory bowel disease treatment AMT-101, including a meeting scheduled with the FDA to discuss a phase 3 trial in chronic pouchitis.