AllRock Bio has reached a critical milestone in its effort to treat severe cardiopulmonary diseases, announcing on April 9, 2026, that it has dosed the first patients in its Phase 2a ROCSTAR trial. The study is testing ROC-101, a potential first-in-class oral pan-rho-associated protein kinase (ROCK) inhibitor designed to address the complex remodeling of blood vessels in the lungs.
The trial focuses on two devastating conditions: pulmonary arterial hypertension (PAH) and pulmonary hypertension associated with interstitial lung disease (ILD-PH). Both diseases cause high blood pressure in the pulmonary arteries, forcing the right side of the heart to work harder to pump blood, which can eventually lead to heart failure and significantly reduced quality of life.
By targeting both ROCK1 and ROCK2 proteins, ROC-101 aims to stop the inflammatory and fibrotic changes that narrow pulmonary vessels. Because it is designed as a once-daily oral medication, the drug offers a potentially simpler administration route than some existing advanced therapies, while targeting disease mechanisms that current vasodilators may not fully address.
The ROCSTAR trial is particularly notable for its design, which evaluates ROC-101 not as a standalone treatment, but as a complementary therapy. This includes a specific arm for patients already receiving sotatercept, a recently approved therapy that targets abnormal cell growth in the pulmonary arteries, suggesting a strategy of “layering” treatments to achieve better patient outcomes.
Targeting the Mechanisms of Pulmonary Hypertension
Pulmonary arterial hypertension is a progressive disease where the small vessels of the lungs narrow, increasing the resistance the heart must push against. While there are 16 approved drugs for PAH, including four major vasodilator classes, many patients still experience disease progression. The “unmet need” in this field is for treatments that are disease-modifying—meaning they don’t just open the vessels, but actually stop or reverse the underlying structural damage.
ROC-101 takes a “pan-ROCK” approach, meaning it inhibits both isoforms of the rho-associated protein kinase. These kinases are central to the proliferative and fibrotic remodeling seen in the lungs. By blocking these pathways, AllRock Bio hopes to reduce pulmonary vascular resistance and improve the functional capacity of patients who are struggling to breathe and move.
The challenge is even more acute for those with ILD-PH. Interstitial lung diseases, such as idiopathic pulmonary fibrosis, scar the lung tissue itself. When pulmonary hypertension develops on top of this scarring, the mortality rate increases and treatment options become severely limited. The ROCSTAR trial represents one of the few focused efforts to provide a targeted pharmacological intervention for this specific patient population.
The ROCSTAR Trial: Design and Objectives
The Phase 2a study is an open-label, multicenter, exploratory trial. This means all participants receive the active drug, and the focus is on gathering a clear signal of efficacy and safety before moving into larger, randomized Phase 3 trials.
The study is recruiting up to 30 patients with PAH and 10 patients with ILD-PH, all of whom must be in World Health Organization (WHO) functional class II or III. These classifications indicate patients who are symptomatic during physical activity but are not yet completely bedridden.
To determine if the drug is working, researchers are using a gold-standard measurement: right heart catheterization. This invasive procedure allows doctors to directly measure the pressure in the pulmonary artery and calculate the pulmonary vascular resistance (PVR).
| Metric | Detail |
|---|---|
| Primary Endpoint | Change in pulmonary vascular resistance (PVR) at week 24 |
| Secondary Endpoints | 6-minute walk distance, NT-proBNP levels, WHO functional class |
| Patient Cohort | Up to 40 total (30 PAH, 10 ILD-PH) |
| Dosing Schedule | Once-daily oral administration |
Beyond the hemodynamics of the heart, the trial will track the “6-minute walk distance,” a practical measure of how much a patient’s exercise tolerance improves. They will also monitor NT-proBNP, a biomarker in the blood that indicates how much stress the heart is under.
Clinical Context and Safety Profile
The transition to Phase 2a follows a Phase 1 study in healthy volunteers, where ROC-101 was reported to be safe and well tolerated. Crucially, the Phase 1 data showed no evidence of hypotension—a common side effect of many pulmonary hypertension drugs that can cause dangerous drops in systemic blood pressure.
Dr. Kate Steiner, MBBS, VP and Head of Clinical Development at AllRock, emphasized the potential for the drug to work alongside existing standards of care. “We believe ROC-101, with its oral, once-daily dosing, has differentiated potential to address underlying disease mechanisms, further reduce pulmonary vascular resistance and improve functional outcomes for patients on top of existing therapies,” Steiner said.
The inclusion of patients on sotatercept is a strategic move. Since sotatercept works through a different pathway—targeting the activin signaling pathway—combining it with a ROCK inhibitor could potentially attack the disease from two different biological angles simultaneously, potentially offering a more comprehensive “disease-modifying” effect.
What This Means for Patients
For patients living with PAH and ILD-PH, the hope is that ROC-101 will move the needle from “managing symptoms” to “altering the course of the disease.” The ability to take a pill once a day, rather than relying solely on complex infusions or multiple high-dose vasodilators, could significantly reduce the treatment burden.
However, as an exploratory Phase 2a trial, the current focus is on safety and “proof of concept.” The results will determine if the drug’s mechanism of action translates from the lab and healthy volunteers into actual clinical benefit for those with severely compromised lung function.
Disclaimer: This article is for informational purposes only and does not constitute medical advice. Patients should consult with their healthcare provider regarding treatment options and clinical trial eligibility.
The next major checkpoint for the ROCSTAR trial will be the 24-week post-treatment assessment, where the primary endpoint of pulmonary vascular resistance will be measured via right heart catheterization. Official updates on the trial’s progress can be monitored via ClinicalTrials.gov under identifier NCT07175038.
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