Ribociclib Plus Letrozole in Italian Male Patients with Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Advanced Breast Cancer: Case Studies of Phase 3b CompLEEment-1 Trial

Abstract

Abstract: Male breast cancer (BC) is rare, globally constituting only 0.5-1% of all patients with BC. In Italy, more than 2000 new male BC cases were registered between 2000 and 2014. The survival rate was lower in males than in females. Delayed diagnosis may be the reason for poorer outcome observed in male BC patients compared with female patients. Due to lack of substantial evidence and low availability of published data on male BC, the current treatment recommendations are based on evidence derived from trials on female patients. In Italy, most of the male BC patients are estrogen and progesterone receptor-positive. Targeted therapy in combination with endocrine therapy provides a clinically meaningful outcome in patients with hormone receptor-positive (HR-positive), human epidermal growth factor receptor 2-negative (HER2-negative) advanced BC. CompLEEment-1 is a single-arm, open-label, multicenter, phase 3b trial investigating the safety and efficacy of a CDK4/6 inhibitor, ribociclib, in combination with letrozole in men and women. Herein, we report the results from a retrospective analysis of five Italian male patients who completed the core phase. In this case series, the combination of ribociclib and letrozole was well tolerated and appeared to be effective in the male cohort with HR-positive, HER2-negative advanced BC in Italy. CompLEEment-1 trial representative of a real-world setting would add value by supporting the existing efficacy and safety profile of ribociclib in combination with letrozole in male patients with HR-positive, HER2-negative advanced BC.

Clinicaltrialsgov registration number: NCT02941926.

Keywords: CDK4/6 inhibitor; case report; male breast cancer; progression-free survival; targeted therapy.

Conflict of interest statement

Grasso D is an employee of Novartis Farma and holds stocks/stock options from Novartis; has received grants, payments, support for attending meetings/travel from Novartis; occupies leadership/fiduciary role in other board, society, committee or advocacy group, paid or unpaid, and participation on a data safety monitoring board/advisory board in Novartis; and has received equipment, materials, drugs, medical writing, gifts, or other services from Novartis. Fenderico N is an employee of Novartis Farma, has received grants, payments, support for attending meetings/travel from Novartis, and has participated on a data safety monitoring board/advisory board in Novartis. Caputo R reports Grant, financial fees, speaker bureau that would give the appearance of potentially influencing. The authors report no other conflicts of interest in this work.

© 2022 Caputo et al.

Figures

Figure 1

(A) Red arrows show lung metastases at baseline and (B) after 12 weeks of therapy with ribociclib.

Figure 2

(A) Red arrows show liver metastases at baseline and (B) after 12 weeks of therapy with ribociclib.

Figure 3

(A) Red arrows show lung metastases at baseline and (B) after 10 cycles of therapy with ribociclib.

Figure 4

(A) Red arrows show liver metastases at baseline and (B) after 10 cycles of therapy with ribociclib.

Figure 5

(A) Red arrows show brain metastases at baseline and (B) after 10 cycles of therapy with ribociclib.

Figure 6

(A) Hepatic complete response and (B) stable brain disease after 31 months of therapy with ribociclib.

Figure 7

(A) and (B) Red arrows show liver metastases after 49 months of therapy with ribociclib.

Figure 8

First CT scan evaluation. (A) Red arrows in the figures show sternum lytic metastasis, (B) lung metastasis of 30 mm diameter, (C) mediastinal lymph node of 30 mm diameter and right breast tumor, and (D) axillary lymph node.

Figure 9

CT scan evaluation after treatment. (A) Red arrows in the figures show sternum lytic metastasis, (B) mediastinal lymph node, (C) axillary lymph node, and (D) lung metastasis.

Figure 10

PET FDG evaluation.

Figure 11

CT scan with bone windows. (A) Humerus shows a lytic lesion into the posterior humeral head, the cortical part of the humerus head is conserved, (B) area of osteosclerosis into the previous lytic lesion, as response to treatment, (C) further osteosclerosis area in relation to the partial recalcification of the lesion.

Figure 12

(A–D and G–J) CT scan of bone, lymph node, lung; (E and F) follow-up CT scan lung and lymph node.