The European Medicines Agency (EMA) has recommended approval for a conditional marketing authorisation in the European Union (EU) of a new advanced therapy medicinal product (ATMP), Zalmoxis, to support stem cell transplantation in patients with high-risk blood cancer.

Orphan medicine Zalmoxis can be used as an adjunctive treatment for adult patients who receive a haploidentical haematopoietic stem cell transplant (HSCT) for several types of blood cancer.

When used on a patient, Zalmoxis will help with immune reconstitution and reduce the risk of graft-versus-host disease.

Haploidentical HSCT involves a patient who receives haematopoietic stem cells, which are non-specialised haematopoietic cells that can develop into different specialised types of blood cell, from a partially matched donor in order to assist the bone marrow in producing healthy blood cells.

The transplant can help treat serious blood diseases, such as haematological malignancies, including leukaemia and lymphoma.

Though transplants from partially-matched donors are more easily available than transplants from perfectly-matched donors, they carry a greater risk of graft-versus-host disease, in which the transplanted cells attack the patient’s organs, thereby causing damage.

Zalmoxis comprises T-cells from the stem cell donor, which, having been separated from the rest of the cells in the transplant, are genetically modified to feature a ‘suicide gene’ called HSV-TK.

Although T-cells can cause graft-versus-host diseases, they are given to transplant patients in order to make the body capable of fighting off infection, enhance the success of the transplant, as well as support long-lasting anti-cancer effects.

"The transplant can help treat serious blood diseases, such as haematological malignancies, including leukaemia and lymphoma."

The suicide gene in Zalmoxis helps the T-cells to be susceptible to a medicine called ganciclovir, which is administered if the patient develops graft-versus-host disease, thereby killing the T-cells that have the suicide gene and preventing further development of the disease.

Zalmoxis was assessed by the Committee on Advanced Therapies (CAT), which is EMA’s specialised scientific committee for ATMPs, including gene or cell therapies.

After completing the assessment, CAT has recommended a conditional marketing authorisation for Zalmoxis, which has been considered by and agreed upon by CHMP.

The CHMP opinion will be further sent to the European Commission (EC) in order to decide on marketing authorisation of Zalmoxis across the EU.

Image: Enlarged image of blood cancer. Photo: courtesy of Christaras A.