OCA seems working

Intercept Pharmaceuticals (NASDAQ:ICPT) is up 3% after hours on modest volume in response to its announcement of positive results from a Phase 2 clinical trial, AESOP, evaluating obeticholic acid (OCA) for the treatment of primary sclerosing cholangitis (PSC). The data were presented at The Liver Meeting in Washington, D.C.

Patients receiving 5 mg OCA per day (with the option of increasing the dose to 10 mg per day) experienced a statistically significant reduction on alkaline phosphatase (ALP) versus placebo at week 24, the primary endpoint. ALP is a liver enzyme biomarker for liver damage (if elevated).

A two-year open-label extension study is ongoing. There are no currently approved therapies for PSC, a rare chronic liver disease characterized by the progressive destruction of bile ducts.

Thanks for sharing. Has anyone discussed this with their heptologist?

Not sure what there is to discuss with hepatologist.

On Monday Intercept announced some minor additional details about earlier announced positive phase 2 trial results. This has been discussed here too in several threads.
This will continue as open label extension trial another couple of years, and phase 3 trial and availability for general public may or may not happen one day. I’m fairly optimistic but I have learnt how slow progress this is…even in best case probably 4-5 years away of being FDA approved drug available in pharmacy near you. Though you may be able to join phase 3 trial and possibly avoid being in placebo group and that way get access to it sooner.

See more here:

As OCA is FDA approved for the treatment of PBC, it is another off-label arrow in the quiver for the proactive PSC patient.

It would be nice to know how many ALP near-normalizers there were as this is the best predictor we have right now as to outcome. It is very interesting that the group that was not taking UDCA had a greater drop in ALP. Of note, OCA (and norUDCA) are resistant to gut bacteria metabolism into LCA, so they likely do a much better job compared to UDCA of diluting the pool of more toxic bile salts.

I forgot off-label use potential. It may be possible for a doctor to prescribe OCA for PSC (with lots of additional paperwork) though insurance would likely not cover it.

Hi jtb. Thanks for the details. As far as I know norUDCA (and OCA?) have the same mechanism as UDCA with the difference highlighted into your post. UDCA was proven to lower the ALP (and improve the clinical symptoms) but it did not alter the time of survival until the transplant, OCA might be doing the same thing… Is that the case, you think? Thanks.

One of the intentions of UDCA was to dilute the toxicity of a patient’s bile salt pool; however, in the high-dose trials we saw that higher doses of urso actually caused an increase in LCA which may have played a role in the 2.1x rise in clinical end points. I was initially skeptical of OCA and norUDCA because they are derivatives of CDCA and UDCA, respectively, and these natural bile salts can be metabolized into LCA by gut bacteria. LCA is particularly relevant for PSC patients because we have an impaired ability to convert it to a less toxic form (see https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4609469/). It appears that OCA is more resistant to being metabolized per http://jpet.aspetjournals.org/content/350/1/56.long (see fig. 4). NorUDCA claims this as well in its patent. They also have other unique characteristics to help minimize bile duct inflammation.

While ALP variations generally are a lousy predictor of outcome, getting ALP down to near normal means a patient is significantly less likely to reach a clinical end point compared to a patient outside of this range. Urso rarely (10%) drops a patient’s ALP from outside the near-normal range to within near-normal and this is why it is often considered not to affect outcome. I was disappointed that only ~20% of patients were able to achieve this through norUDCA. Hopefully we can get some data on OCA near-normal responders. My opinion is that these synthetic bile salts will likely minimize the impact of PSC inflammation and buy time for a subset of the PSC population (like UDCA, but hopefully benefiting a larger group than UDCA).

Jtb thanks very much. Your info is more than helpful. I’m grateful that you put so much effort in untangling all of those journals papers and explaining them to us in a language that is easy to understand. All the best. Daniela

Thanks for the great summary. I’m not that confident about norUDCA. I read that article and one figure was particularly troublesome to me. I’ll post that later here.
As to OCA, there are about 17(ish) number of PBC patient death associated with it, including some quite early stage patient at normal dose. They probably need to sought that out first.