The pharmaceutical company Lilly has announced that its cancer drug abemaciclib is available in Spain for adjuvant treatment, that is, in addition to the one received first, in a subtype of breast cancer with a high risk of relapse.

This oral drug, which has been on the market since 2019 for metastatic disease, can now be administered with curative intent. Thus, it becomes the first and only cyclin inhibitor authorized in adjuvant use, after the main treatment or surgery, with the aim of preventing relapse.

It is the first time in more than 20 years that it has been possible to reduce the number of recurrences in high-risk patients.. The previous advance in the adjuvant therapy of hormone-dependent tumors occurred with the advent of aromatase inhibitors.

For the Spanish subsidiary of this Indianapolis-based multinational, abemaciclib is a source of pride, since this inhibitor was discovered at Lilly's R&D facilities in Alcobendas (Madrid) and Spain has played a leading role in its clinical development. .

Objective: reduce relapses

According to estimates by the Spanish Society of Medical Oncology (SEOM), in 2023 it is expected that more than 35,000 new cases of breast cancer will be diagnosed. Of these, seven out of ten will be HR+ and HER2- breast tumors.. Although 95% of breast tumors are detected in their early stages, one in five patients will suffer a recurrence throughout their lives.. And 50% of those relapses occur in the first two years after surgery or chemotherapy.

Within patients with luminal breast cancer, a group has been identified, representing between 15% and 18% of the total, who are considered to be at very high risk and present a 40% risk of recurrence at 10 years.. These patients have four or more positive nodes, or between one and three positive nodes and at least one additional poor prognostic factor, such as a histological grade 3 or a tumor greater than or equal to 5 cm.

To determine the effect of abemaciclib on relapse prevention in this subgroup of high-risk patients, the clinical trial included 5,000 patients (750 of whom were Spanish) with a mean age of 51 years.. The results of this study have been the basis for Health to give the green light to financing the drug in this new indication.

All women received standard treatment (chemotherapy, surgery, radiation therapy, and hormonal therapy), but were randomized to one group receiving abemaciclib twice daily for two years.

Miguel Martín, president of the Spanish Breast Cancer Research Group (Geicam) and head of the Medical Oncology Service at the Gregorio Marañón Hospital in Madrid, explained that the results of the four-year follow-up show a relative reduction in the risk of relapse (reappearance of cancer in the breast or in distant organs) of 40%.

In absolute terms, 86% of women in the abemaciclib arm were relapse-free compared with 80% in the control group.. “After four years we prevented 6% of patients from relapsing. That may seem little, but it is a lot.. It's one of the most impressive figures in terms of avoiding relapses.”

The clinical benefits of the drug were demonstrated in all subgroups of patients represented in the study: premenopausal, perimenopausal, and postmenopausal women, and in men with this oncological pathology.

Martín has insisted on the impact of the clinical benefit of the drug “in exchange for a toxicity that is basically gastrointestinal, can be treated with medication and disappears after two or three months.”

The drug is associated with diarrhea, which, according to Martín, is well managed with medication. It can also cause fatigue and neutropenia, “which has no clinical relevance”. “But the important thing,” he emphasized, “is that all these side effects disappear after two years, when treatment is stopped.”