Research The Bayer Scientific Magazin, Edition 28

The shape of the disease: the red blood cells are shaped like sickles, which means that they cannot transport as much oxygen.

NEW THERAPEUTIC APPROACHES FOR HEMOGLOBIN DISORDERS

Treatments for sick blood cells

If our red blood cells cannot transport enough oxygen, the whole body suffers as a result. Organs become undersupplied or may 

even fail. A genetic mutation in the oxygen transporter hemoglobin is often the root cause of diseases which are categorized 

under the medical term hemoglobinopathies. Current treatment options are limited, however, and often associated with side 

effects. Scientists at Bayer HealthCare are therefore working on new therapies to help patients with hemoglobinopathies.

Our blood transports oxygen and nutrients to each individu-

al cell. Roughly half of the blood volume is made up of cells, 

primarily red blood cells (erythrocytes). These cells use the red 

blood pigment hemoglobin, an iron-containing protein, to trans-

port oxygen: like a molecular vessel, it collects this essential gas 

in the lungs and delivers it to the cells and organs throughout 

the body. Some people have an inherited mutation in their he-

moglobin gene that may prevent the efficient transport of ox-

ygen. “These individuals produce a ‘faulty’ version of the blood 

pigment called sickle hemoglobin or hemoglobin S, which is not 

able to transport the same amount of oxygen as the normal 

form. This condition is called sickle-cell anemia, because the 

red cells are shaped like a sickle,” says Dr. Katalin Kauser, Head 

of Hematology Research at Bayer HealthCare in San Francisco’s 

U.S. Innovation Center. Sickle cells are stiff and sticky and tend to 

block the blood flow in the blood vessels of organs, which then 

receive an insufficient supply of oxygen, causing patients to be-

come more quickly fatigued. In more severe cases, however, the 

small blood vessels can occlude, causing pain and organ damage. 

“This can lead to organ failure. The life expectancy of patients 

with sickle cell disease is only 40 to 50 years. Devastating pain 

crises are part of their lives,” explains Kauser.

Sickle-cell anemia is the most common and severe hemoglo-

binopathy. Seven percent of the world’s population carries the 

gene mutation responsible for this condition. It is particularly 

common in the regions at the equator – in some areas, more 

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tion, the erythrocytes look normal from the outside but in fact 

they carry a mutated blood pigment. Patients suffering from 

thalassemia also produce abnormal hemoglobin, causing rapid 

breakdown of blood cells. The current therapy for these patients 

consists of repeated blood transfusions to manage the resulting 

anemia. However, with every transfusion, the iron bound in the 

red blood cells is also transferred, which the body of thalassemia 

patients cannot actively eliminate. “This leads to an excess of 

iron, which is taken up by different organs including the liver, 

heart or kidneys. Excess iron in the organs can lead to damage 

and ultimately organ failure,” explains Kauser. Her group, togeth-

er with the experts from the UCSF Benioff Oakland, is therefore 

also focusing its work on regulating the uptake of iron into the 

blood. 

The Bayer scientists are contributing their experience in de-

velopment of active substances to the collaboration, while  

UCSF Benioff Oakland is sharing its comprehensive research 

knowledge and clinical experience with patients. “We recent-

ly extended the agreement with UCSF Benioff Oakland by two 

more years,” says Dr. Lisa Mendoza, Associate Director of the U.S. 

Science Hub of Bayer HealthCare and Alliance Manager of the 

collaboration. If the research path that the experts of Bayer and 

UCSF Benioff Oakland have taken is successful, hemoglobinopathy 

sufferers could soon be able to get back some quality of life. After 

all, being able to relieve the symptoms of these diseases and in the 

future possibly even cure them is a promising prospect.

Photos: Omikr

on Science/Gettyimages (1), Josh Edelson (1)

than 19 in every 1,000 newborn children are affected. At present 

there is only one drug therapy approved for the condition. It 

was originally developed to treat cancer and is able to reduce 

the number and severity of the pain crises. “And there is also a 

cure for this disease:  a bone marrow transplant,” explains Kaus-

er. “However, it is difficult to find a matching donor and there 

are risks associated with it.” Since 2012, Bayer scientists have 

been working closely with the UCSF Benioff Children’s Hospital 

Oakland, California. This hospital is one of the leading centers of 

academic research on hemoglobinopathies in the United States 

and the largest clinical center for sickle-cell disease on the West 

Coast. 

The scientists and physicians at UCSF Benioff Oakland are 

working together with the Bayer teams to develop a therapy for 

sickle-cell anemia. “Due to their sickle shape, red blood cells of 

affected individuals are fragile and shorter-lived,” says Kauser. 

In contrast to healthy, disk-shaped blood cells, they easily perish 

in circulation and release their hemoglobin. The broken cells and 

the excess amounts of the iron-containing red pigment have to 

be removed from the blood as they would otherwise damage 

organs such as the heart. “We want to help the body to carry out 

this ‘detoxifying’ process. Our team is working on novel ideas to 

decrease the concentration of hemoglobin degradation products 

in the blood,” explains the Bayer scientist. This should help the 

liver and spleen to manage the overload and protect the different 

organs against damage. “At present we are comparing the mea-

surements from tests with cell cultures and animal models with 

the values from real-life patient samples from UCSF Benioff Oak-

land,” says Kauser, summarizing the current status. “If it all goes 

according to plan, we might soon be able to take a first active 

substance into early-stage clinical testing.” This treatment could 

relieve the symptoms of sickle-cell anemia, which for sufferers 

would already be a huge relief. “But our long-term objective for 

drug development is in fact to cure this disease,” says Kauser. She 

and her team are therefore also exploring novel forms of therapy 

that work directly at the gene level.

The scientists at Bayer are also investigating another type of 

hemoglobinopathy, a disease called thalassemia. In this condi-

www.research.bayer.com/

hemoglobinopathies

More information on this topic

Distribution of  

sickle-cell anemia 

Many people living near the equator suffer from sickle cell anemia. 

Africa is particularly heavily affected.

Fighting pain together: Dr. Katalin Kauser and her team are work-

ing to alleviate the pain suffered by hemoglobinopathy patients.

Researchers combine specialist knowledge in drug 

development with patient experiences 

Source: Sickle Cell Information Center

0.18 0.15 0.12 0.09 0.06 0.03 0.00

HbS allele frequency (%)

Hemoglobinopathies

  MEDICINE

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