Sibling Stem Cell Transplant and JAK Inhibitors: New Hope for HIV Remission in the ‘Oslo Patient’

Recent findings presented at the Conference on Retroviruses and Opportunistic Infections (CROI 2025) in San Francisco have highlighted two new cases of HIV remission, offering critical insights into the pursuit of a functional cure. Among these is the “Oslo patient,” whose case combines a rare genetic mutation with a specific drug treatment to achieve long-term viral suppression without the need for daily medication.

The Case of the Oslo Patient

The individual known as the “Oslo patient” is currently in remission 48 months after receiving a bone marrow transplant and has remained off antiretroviral therapy (ART) for 24 months [2]. This patient underwent an allogeneic hematopoietic stem cell transplant from a sibling to treat cancer [1].

The Role of the CCR5 Mutation

A key factor in this remission is the genetic profile of the stem cell donor. The sibling donor possessed the CCR5 Δ32/Δ32 mutation, a rare genetic variation that makes cells resistant to HIV infection [4]. This mutation prevents the virus from entering the host’s immune cells, effectively blocking its ability to replicate.

Ruxolitinib and the Viral Reservoir

Whereas the mutation provided a defense, the Oslo patient likewise received ruxolitinib, a first-generation JAK (janus kinase) inhibitor [3]. Originally administered to treat severe graft-versus-host disease (GVHD) following the transplant, ruxolitinib is an immunomodulatory drug that may also reduce HIV viral reservoirs [1].

The significance of JAK inhibitors is underscored by the “Geneva patient,” who also achieved remission using ruxolitinib despite receiving stem cells from a donor who did not have the CCR5 mutation [3]. This suggests that JAK inhibitors may offer a separate, potent pathway toward eradicating the HIV reservoir.

The Chicago Patient and the Path to a Functional Cure

Alongside the Oslo case, the “Chicago patient” has also shown signs of remission. After an initial viral rebound during a treatment interruption, this patient has remained in remission for 10 months after stopping antiretrovirals a second time [1]. If these two men remain in remission, they will mark the ninth and tenth documented cases of a functional cure resulting from stem cell procedures.

Why This Matters for the Future of HIV Treatment

For the vast majority of people living with HIV, stem cell transplantation is too risky to be a viable treatment option unless they are already facing advanced cancer [1]. However, these rare cases provide a blueprint for scientists.

Standard antiretroviral therapy (ART) can suppress the virus indefinitely, but it cannot eliminate the “reservoir”—the genetic blueprints HIV inserts into host cells [1]. By comparing the similarities between the Oslo, Geneva, and Chicago patients, researchers hope to develop more accessible cure approaches that do not require high-risk transplants.

Key Takeaways: HIV Remission Breakthroughs

• Oslo Patient: Remission achieved via sibling transplant (CCR5 Δ32/Δ32 mutation) and ruxolitinib treatment.
• Ruxolitinib: A JAK inhibitor that may reduce the HIV reservoir, as seen in both the Oslo and Geneva patients.
• Functional Cure: These cases represent the 9th and 10th instances of HIV remission following stem cell transplants.
• Clinical Goal: Researchers are using these cases to find commonalities that can be translated into safer, wider-reaching cure strategies.

Frequently Asked Questions

What is a “functional cure” for HIV?

A functional cure occurs when a patient can maintain undetectable levels of the virus without the need for ongoing antiretroviral therapy (ART), even though the virus may not be entirely eradicated from the body.

Can anyone acquire a stem cell transplant to cure HIV?

No. Stem cell transplants carry severe risks and are currently only administered to patients with life-threatening conditions, such as advanced cancer [1].

What is the CCR5 Δ32 mutation?

It is a genetic mutation that alters the CCR5 receptor on the surface of white blood cells, preventing HIV from entering and infecting those cells [3].