La Jolla posts mixed bag of phase 3 data, raising hopes of FDA approval but calling commercial potential into question

La Jolla Pharmaceutical has posted a full look at data from a phase 3 trial of its vasodilatory shock candidate LJPC-501. Key findings are in line with the earlier, positive top-line data drop but the picture becomes muddier beyond the primary endpoint, with the lack of improvement to mortality and total organ function raising doubts about whether LJPC-501 can win over physicians.

The study set out to link LJPC-501, synthetic angiotensin II, to increases in blood pressure in the three hours after treatment. As La Jolla revealed in February, 70% of the 163 patients in the treatment arm had a blood pressure response, as compared to 23% in the similarly-sized placebo cohort. That meant the study met its primary endpoint, a positive result that should stand La Jolla in good stead when it submits the data to the FDA.

What is more questionable is whether the current data are strong enough to make a commercial success of LJPC-501. The presentation of the full data in the New England Journal of Medicine has done little to quell these doubts.

“With positive primary outcome, we continue to view FDA approvability as high. However, given [the] lack of [statistically significant] mortality benefits and total organ function improvement—except for catecholamine use reduction—its commercial potential could be debatable,” Jefferies Eun Yang, Ph.D., wrote in a note to investors.

The questions about the commercial prospects of LJPC-501 stem from its performance against the secondary endpoints flagged up by Yang. By seven days into the study, 29% of people who received LJPC-501 had died. That compared to 35% in the placebo arm. After 28 days, the figures for the treatment and placebo arms were 46% and 54%, respectively. The difference fell short of statistical significance.

La Jolla posted similarly lackluster data on the effect of LJPC-501 on organ function, as measured on the sequential organ failure assessment (SOFA) score. LJPC-501 outperformed placebo against the cardiovascular SOFA score as a result of lower use of the vasopressors catecholamines. But LJPC-501 failed to move the needle when the function of all organs was considered.

The performance of LJPC-501 against the secondary mortality and SOFA endpoints leaves La Jolla facing the task of convincing physicians to use the drug without being able to point to its effect on how long their patients will live or how well their organs will function.

In its favor, LJPC-501 increases blood pressure via a different mechanism than existing vasopressors catecholamines and vasopressin. This gives it a route into the tool kits of physicians who treat distributive shock patients for whom first-line treatment with catecholamines is ineffective.