EU Greenlights Rezurock for Chronic GVHD: A Much-Needed Option for Late-Line Patients

A new treatment option has entered the European market for one of the most challenging post-transplant complications.

The European Commission has granted conditional marketing authorisation to Rezurock (belumosudil) for treating chronic graft-versus-host disease (GVHD).

This decision follows a positive recommendation from the European Medicines Agency’s CHMP in January 2026.

What This Approval Means?

Rezurock is now approved in the EU for:

• Adults and children ≥12 years
• Minimum body weight: 40 kg
• Patients with limited or failed prior treatment options

This is not a full approval. It’s a conditional marketing authorisation, which means:

• Approval is based on existing clinical evidence
• A confirmatory randomised controlled trial is mandatory
• Continued approval depends on future data

Why Chronic GVHD Is So Difficult to Treat?

Graft-versus-host disease (GVHD) occurs after allogeneic stem cell transplantation.

What happens:

• Donor immune cells attack the patient’s body
• Leads to inflammation and fibrosis
• Multiple organs can be affected

The burden:

• Affects up to 50% of transplant patients
• Major cause of late mortality and morbidity
• Often becomes chronic and debilitating

For many patients: Treatment options run out quickly. Nearly 1 in 2 patients require third-line therapy, where choices have historically been limited.

The Drug: How Rezurock Works?

Rezurock (belumosudil) is a:

• Selective ROCK2 inhibitor (rho-associated coiled-coil kinase 2)

Why this matters:

ROCK2 plays a role in:

• Immune regulation
• Inflammation
• Fibrosis

By targeting this pathway, Rezurock aims to:

• Reduce immune overactivation
• Limit tissue damage
• Improve functional outcomes

The Data Behind the Decision

The approval is supported by multiple datasets, including the ROCKstar Phase II trial.

Key highlights:

• Overall Response Rate (ORR): 74%
• Statistically significant (p < 0.0001)
• Durable responses observed
• Patients had 2–5 prior lines of therapy

Safety profile:

Most common side effects:

• Fatigue (46%)
• Diarrhoea (35%)
• Nausea (35%)
• Dyspnoea (32%)
• Cough (30%)
• Upper respiratory infections (26%)

Overall: The treatment was generally well tolerated.

Global Footprint So Far

Rezurock is not new globally. It is already approved in:

• United States
• United Kingdom
• Canada
• China

Across markets:

• 20+ countries approved
• 20,000+ patients treated since 2021

This EU approval expands access significantly.

Orphan Drug Status: Why It Matters

Rezurock received orphan designation in 2019.

Following this approval:

• The EMA’s Committee for Orphan Medicinal Products confirmed continued designation

Benefits include:

• Regulatory incentives
• Market exclusivity
• Support for rare disease innovation

What Experts Are Saying?

Mohamad Mohty emphasized the unmet need:

“Chronic GVHD is serious and life-threatening… this approval offers a meaningful new option.”

From industry, Olivier Charmeil added:

“Nearly one in two patients need third-line treatment, yet options have remained limited.”

What Comes Next?

The story isn’t finished. Under conditional approval, Sanofi must:

• Conduct a confirmatory randomised controlled trial
• Validate long-term efficacy and safety

Meanwhile, ongoing studies are exploring:

• Use in younger paediatric populations (≥1 year)
• Other conditions like chronic lung allograft dysfunction

The Real Takeaway

This approval fills a critical gap—but with caveats.

What’s strong:

• High response rates in heavily pretreated patients
• Novel mechanism (ROCK2 inhibition)
• Real-world usage already established

What’s pending:

• Confirmatory Phase III data
• Long-term comparative effectiveness

Final Thoughts

For chronic GVHD patients who have exhausted options, Rezurock is not just another drug—it’s a lifeline with conditions attached. The opportunity is clear.

Now it comes down to one question: Can confirmatory data convert this conditional win into a full standard-of-care shift?