Low counts, fever risk and hair loss on sacituzumab govitecan

Sacituzumab govitecan carries a chemotherapy drug to breast cancer cells, but some of that drug also reaches healthy, fast-dividing cells, especially in the bone marrow and hair roots. In the bone marrow it slows the making of neutrophils, the white cells that fight bacterial infection. A low white cell count is the most common serious side effect of this medicine, and the official label carries a boxed warning about it. In the main studies, around half of people had a severe drop at some point, while a much smaller number developed a fever with a low count, which is a medical emergency. Counts usually fall in the week or two after doses and then recover. For this reason a full blood count is checked before every infusion, on day one and day eight of each three-week cycle. If the count is too low, the dose is held until it recovers, and growth factor injections may be used to help later cycles. The medicine can also lower haemoglobin and, less often, platelets. Hair loss is common too, usually starting a few weeks into treatment, and hair generally grows back after it ends. Knowing the warning signs of infection, and acting on a fever at once, keeps this side effect as safe as possible.

A fever is an emergency

A raised temperature or shivering during treatment needs medical advice straight away, day or night.

Counts are checked before each dose

Your team will not give a dose when your white cell count is too low.

Hair loss is usually temporary

Most people's hair starts to grow back within a few months of finishing.

Low counts are expected, and your team plans for them. What cannot be known in advance is how deeply your own counts will fall.

Delays are common

Many people have at least one dose held or lowered because of their counts, and that is a normal safety step.

Growth factors help but have side effects

They often cause bone or back aches for a day or two.

Hair loss cannot always be prevented

Scalp cooling has not been well studied with this medicine, and results vary.

What this page cannot tell you

It cannot tell you whether a particular temperature or symptom is safe to watch. Always ask your team.

Losing your hair can feel harder than many other side effects, because it is visible to everyone. Preparing for it often helps.

Before it starts

Some people cut their hair short beforehand so the change feels less sudden. Choosing a wig, scarf or cap early lets you match your usual look.

While it is falling

Use a mild shampoo, a soft brush and a satin pillowcase. Protect your scalp from sun and cold.

Regrowth

Hair usually starts to return a few months after treatment ends. It may be softer, curlier or a different colour at first.