Ribociclib (Kisqali) as part of first-line hormone therapy for advanced breast cancer in women after menopause

In 2020, the Institute for Quality and Efficiency in Health Care (IQWiG, Germany) looked into the advantages and disadvantages of ribociclib (Kisqali) as part of first-line hormone therapy compared with the standard treatments for advanced hormone-receptor-positive and HER2-negative breast cancer in women after menopause. Ribociclib was assessed in combination with an aromatase inhibitor and in combination with the anti-estrogen drug fulvestrant.

Ribociclib in combination with an aromatase inhibitor

The manufacturer provided one study comparing the combination of ribociclib and the aromatase inhibitor letrozole with the standard treatment with letrozole alone.

This study, which started in 2013, has 668 women in it. Half of them are having treatment with ribociclib and letrozole, while the other half are using letrozole and a placebo (fake treatment). So far, the study has shown the following:

What are the advantages of ribociclib?

Life expectancy: The study suggests that the combination of ribociclib and letrozole has an advantage here when compared to letrozole alone. Patients who had treatment with ribociclib and letrozole lived longer than patients who were given only letrozole. About 41 out of 100 women in the study who had treatment with ribociclib and letrozole have passed away so far, compared to 50 out of 100 women who used letrozole alone.

Health-related quality of life (perspective on the future): The women in the study were asked whether they were worried about their future health. Early analyses suggest that the patients who had treatment with ribociclib and letrozole were more positive about their future than patients who used letrozole on its own.

What are the disadvantages of ribociclib?

Shortness of breath: The study suggests that, in patients over the age of 65, shortness of breath was more common in those who had treatment with ribociclib and letrozole than it was in those who received letrozole on its own. About 10 out of 100 people who were given ribociclib and letrozole had shortness of breath, compared to about 2 out of 100 people in the comparison group.

Severe side effects: The study suggests that ribociclib has a disadvantage here. When given ribociclib in addition to the standard treatment, serious side effects occurred after about 1 month on average (median value). In those women who only received letrozole, this happened after about 28 months on average (median value). When the patients were also given ribociclib, about 88 out of 100 people developed severe side effects, compared to about 42 out of 100 people in the group that only had treatment with letrozole.

The severe side effects also include:

  • Severe disorders of the blood and lymphatic system: The most common of these side effects was severe neutropenia. In neutropenia the person has a lack of immune system cells. About 56 out of 100 women who were also given ribociclib developed a severe disorder of the blood or lymphatic system, compared to about 3 out of 100 women who had treatment with letrozole alone.
  • Serious infections: About 9 out of 100 women who were also given ribociclib had this severe side effect, compared to about 4 out of 100 women who only had treatment with letrozole.

The study also suggests that ribociclib has disadvantages regarding other side effects, some of which are severe. These include:  

  • Eye problems
  • Skin problems
  • Severe gastrointestinal (stomach and bowel) problems

Treatment stopped due to side effects: Here too, the study suggests that it has a disadvantage: About 20 out of 100 women who had treatment with ribociclib stopped their treatment, compared to about 5 out of 100 women who had treatment with letrozole alone. Usually the reason was severe side effects, such as severe gastrointestinal problems.

No difference

There were no differences between women who had the standard treatment and those who received ribociclib in terms of other aspects of health-related quality of life, aside from their perspective on the future. There was also no difference regarding further symptoms of the cancer, such as exhaustion or pain.

What remains unanswered?

The manufacturer didn’t provide any suitable data regarding the patients' health.

Ribociclib combined with fulvestrant

Here the manufacturer provided data from one study in which 374 women were given ribociclib in combination with fulvestrant and 198 women received a standard treatment of fulvestrant in combination with a placebo (fake medication). The following results were found in these women:

What are the advantages of ribociclib?

Lífe expectancy: The study suggests that ribociclib has an advantage over the standard treatment here. About 33 out of 100 women who had treatment with a combination of ribociclib and fulvestrant have died so far in the study, compared to about 45 out of 100 women who had treatment with fulvestrant alone.

What are the disadvantages of ribociclib?

Serious side effects: Overall, the study suggests that ribociclib has a disadvantage here. In the group that had additional treatment with ribociclib, about 82 out of 100 women experienced serious side effects. This was the case in about 36 out of 100 women who received only fulvestrant.

These serious side effects included blood disorders and lymphatic system disorders: The most common of these side effects was severe neutropenia. In neutropenia, the person has a lack of immune system cells. About 48 out of 100 women who were also given ribociclib developed a severe disorder of the blood or lymphatic system, compared to about 3 out of 100 women who had treatment with fulvestrant alone.

Treatment stopped due to side effects: The study suggests that ribociclib has a disadvantage here: About 16 out of 100 women who had additional treatment with ribociclib stopped their treatment due to the side effects, compared to about 7 out of 100 women in the other group.

Diseases affecting the eyes and the skin: The study suggests that ribociclib has a disadvantage here: Compared to the women who only had treatment with fulvestrant, about twice as many of those who also received ribociclib developed eye or skin diseases.

No difference

Symptoms of the disease: There was also no difference between the groups in terms of symptoms such as exhaustion or sleep problems.

Health-related quality of life: There was no difference here either.

What remains unanswered?

The study didn’t include any suitable data about the effect of ribociclib on general health or pain.

More information

This information summarizes the main results of a review produced by the Institute for Quality and Efficiency in Health Care (IQWiG, Germany). The review was commissioned by the German Federal Joint Committee (G-BA) as part of the “early benefit assessment of medications.” On the basis of the review and the hearings received, the G-BA passed a resolution on the added benefit of ribociclib (Kisqali).

Labels: C50, Kisqali, Ribociclib