Health economic evaluation of the gene therapy Zynteglo for transfusion-dependent beta-thalassaemia

TLV has performed a health economic evaluation at the request of the 21 Swedish Regions for the gene therapy Zynteglo (autologous cd34+ cells encoding βA-T87Q-globin gene). The evaluation concerns Zynteglo when used to treat patients 12 years and older, with transfusion-dependent β-thalassaemia who do not have a β0/β0 genotype, and for whom haematopoietic stem cell transplantation is appropriate, but a donor is not available.

Beta-thalassaemia is a rare genetic blood disease caused by deficit in the beta-globin protein. Beta-thalassaemia causes anaemia of varying severity with symptoms as tiredness, weakness and shortness of breath. For transfusion dependent patients, the anaemia is so severe that regular blood transfusions are needed. The blood transfusions reduce the anaemia, but causes an iron overload that can be harmful, and is therefore treated with iron chelation therapy. Well managed patients are generally relatively healthy, but the treatment is life-long and requires good compliance.

The severity degree of beta-thalassaemia in patients suited for Zynteglo treatment is assessed to be moderate on a group level. The rational being that while blood transfusions and iron chelation therapy are demanding and lifelong, the impact of the disease on the health-related quality of life is moderate.

Blood transfusions and iron chelation therapy is the relevant comparator of Zynteglo.

The majority of patients (20 of 24) treated with Zynteglo in clinical trials achieved transfusion independence in clinical trials. The transfusion need was reduced in the remaining patients (4 of 24). The effect is expected to be lifelong but there is uncertainty as long-term data are limited.
The company’s price of Zynteglo is almost a 17 million SEK for a one-time treatment. This should be compared to the cost of a life-long treatment with blood transfusions and iron chelation therapy totaling almost 7.2 million SEK with a discount rate of 3 percent.

TLV presents two scenarios, with and without survival gains, where the cost per quality adjusted life year gained was estimated at approximately 1 761 000 SEK and 2 137 000 SEK respectively.

The evaluation of Zynteglo is part of a Nordic collaboration

TLV has together with the corresponding agencies in Finland and Norway within FINOSE, written a joint assessment report for Zynteglo. This report has been a basis for the TLV evaluation of Zynteglo.
FINOSE is a collaboration between the HTA agencies Fimea (Finland), Norwegian Medicines Agency (Norway) and TLV (Sweden). The co-operation consists in the three agencies writing joint assessment reports for pharmaceutical products, that contain both relative clinical and health economic assessments. This is the third joint assessment report within the FINOSE collaboration. Previously, the drug Tecentriq in combination with the substances bevacizumab, paclitaxel and carboplatin against metastatic non-squamous non-small cell lung cancer (NSCLC), and the drug Xtandi for treatment of adult men with high-risk non-metastatic castration-resistant prostate cancer, have been evaluated within FINOSE.