Xoma up on broadly positive data, but questions remain

Analysts want to know of the drug's long-term potential and said the data were still too early

Xoma says it has made good on its proof-of-concept test for its experimental drug XOMA-358 in postbariatric surgery hyperinsulinism (PBS) and congenital hyperinsulinism (CHI) as its shares jumped 7.7% after hours.

In all, the company presented updated data from 13 patients (up 2 from former data posts) treated with PBS and 14 with CHI (up from 7 previously reported) in phase 2a trials, and the biotech said that in the latter group, in acute studies, “have met their objectives of establishing initial safety and 358 proof-of-concept aged 12 and up across several dosing levels.”

It said it is also “nearing” a multi-dose study in children with CHI aged 2 and up, which is slated to be done in the U.K.

Meanwhile, the PBS study has completed dosing in the single-dose cohorts, and has also met its objectives, the biotech said, adding that a a multi-dose study has also been started.

The drug is a fully human negative allosteric modulating insulin receptor antibody derived from the XMet platform.

Analysts at Jefferies took a measured view, saying: “Given the limited data we believe it is still too early to build XOMA-358 into Xoma’s valuation. Two critical features that need to be determined are the durability of the treatment (and long-term treatment potential) and whether XOMA-358 raises the glucose levels in younger patients (patients between 2-12). The latter is important as some CHI patients tend to 'outgrow' their CHI around the ages of 10-15yrs.”

A lot is riding on this med as back in 2015, the company was hit by a catastrophic failure of a key development program that knocked Xoma into penny stock territory. The company reported that its Servier-partnered drug for Behcet's disease flunked a late-stage study.

The biotech, which reportedly laid off staff in a reorganization, was left with a share price that had shrunk 80%, but later signed a life-extending deal with Novartis that involved out-licensing a cancer med to its long-term partner. 

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