Gary Owens, MD, president of Gary Owens Associates, describes mechanisms, trials of treatments in the works for pulmonary arterial hypertension (PAH).
We have a lot of future potential treatments for this disease, said Gary Owens, MD, president of Gary Owens Associates.
Can you decribe recent advancements in therapies for pulmonary arterial hypertension (PAH)?
One that comes to mind right off the top of the head is Ralinepag. It's a selective, non-prostanoid prostacyclin receptor agonist. That's quite a mouthful by the way, and it's in phase 3 studies now. It's part of the ADVANCE clinical program, and it's really going to assess this agent, the impact on morbidity and mortality. And just as an aside, most of the agents we use to treat PAH right now improve outcomes, improve patient quality of life, improve symptoms, but very few of them have shown any impact on mortality. So, you know, this trial hopes to show some impact on mortality.
Another agent out there in the pipeline is sotatercept. It's a selective ligand trap for members of the [transforming growth factor β (TGF-β)] superfamily. It rebalances signaling, and hopefully will restore vascular homeostasis. So, you know, maybe even this drug has a potential to reverse vascular remodeling. Now, the difference here is it is a [subcutaneous] injection, [it] needs to be given fairly frequently, at least in the clinical trials, once every 3 weeks. It's in phase 2 trials in the STELLAR program. And they're really looking at adding this agent on to background therapy and here, it looks like those trials should read out towards the end of 2022. The primary endpoint of the trial is going to be change in baseline of the 6 minute walk test, as well as improvement in the WHO functional categories. [It's] also looking at time to death or clinical worsening for this drug.
And then there's some other agents that are in development that are not quite as far along. One is an actual drug we know well in the treatment of [chronic myeloid leukemia], a tyrosine kinase inhibitor, imatinib and they're looking at an inhaled version for that because it targets platelet-derived growth factor, or PDGF. And that's being investigated.
One with another bit of a tongue tying name is pemziviptadil. It's a subcutaneous vasoactive intestinal polypeptide. Bardoxolone is the nuclear factor erythroid 2–related factor 2 (Nrf2) drug and then there's even an albumin bound mTOR inhibitor investigation.
So we have a lot of potential future treatments for this disease, many of which will be add-on therapies or in some cases, replacement therapies for existing drugs. And I mean, the ultimate hope is to improve not only clinical outcomes, but to show impact on mortality. So certainly a ripe area for investigation and an area I think payers have to be very cognizant of because it's going to be continuously changing.