Summary of the safety profile
The most common adverse reactions in patients who received Itovebi were hyperglycaemia (59.9%), stomatitis (51.2%), diarrhoea (48.1%), thrombocytopenia (48.1%), fatigue (37.7%), anaemia (37%), nausea (27.8%), decreased appetite (23.5%), rash (22.8%), headache (21%), weight decreased (17.3%), vomiting (14.8%), and urinary tract infection (13%).
The most common serious adverse reactions reported in patients who received Itovebi were anaemia (1.9%), diarrhoea (1.2%), and urinary tract infection (1.2%).
Permanent discontinuation of Itovebi due to an adverse reaction occurred in 3.1% of patients. The adverse reactions leading to permanent discontinuation of Itovebi were hyperglycaemia (1.2%), stomatitis (0.6%), alanine transaminase (ALT) increased (0.6%), and weight decreased (0.6%).
Tabulated list of adverse drug reactions
Adverse drug reactions, based on data from 162 patients with locally advanced or metastatic breast cancer who received Itovebi in combination with palbociclib and fulvestrant in the INAVO120 Phase 3, randomised study, and from post-marketing surveillance are listed by MedDRA system organ class in Table 6. The median duration of Itovebi treatment at the time of the analysis was 9.2 months (range: 0 to 38.8 months).
Within each system organ class, the adverse reactions are ranked by frequency, with the most frequent reactions first. The corresponding frequency category for each adverse drug reaction is based on the following convention: very common (≥ 1/10), common (≥ 1/100 to < 1/10), uncommon (≥ 1/1 000 to < 1/100), rare (≥ 1/10 000 to < 1/1 000), very rare (< 1/10 000), not known (cannot be estimated from available data). Within each frequency grouping, adverse reactions are presented in order of decreasing seriousness.
Table 6: Adverse drug reactions observed in patients treated with Itovebi
| System organ class Adverse reaction | Itovebi + palbociclib + fulvestrant N=162 |
| Frequency category (all grades) | All grades (%) | Grade 3-4 (%) |
| Infections and infestations |
| Urinary tract infection | Very common | 13 | 1.2* |
| Blood and lymphatic system disorders |
| Thrombocytopenia | Very common | 48.1 | 14.2 |
| Anaemia | Very common | 37 | 6.2* |
| Metabolism and nutrition disorders |
| Hyperglycaemiaa | Very common | 59.9 | 5.6* |
| Decreased appetite | Very common | 23.5 | 0 |
| Hypokalaemia | Very common | 16 | 2.5 |
| Hypocalcaemia | Common | 8.6 | 1.2* |
| Ketoacidosis | Uncommonb | - | - |
| Nervous system disorders |
| Headache | Very common | 21 | 0 |
| Eye disorders |
| Dry eye | Common | 8.6 | 0 |
| Gastrointestinal disorders |
| Stomatitisc | Very common | 51.2 | 5.6* |
| Diarrhoea | Very common | 48.1 | 3.7* |
| Nausea | Very common | 27.8 | 0.6* |
| Abdominal pain | Very Common | 15.4 | 0.6* |
| Vomiting | Very common | 14.8 | 0.6* |
| Dysgeusia | Common | 8.6 | 0 |
| Dyspepsia | Common | 8 | 0 |
| Skin and subcutaneous tissue disorders |
| Rashd | Very common | 22.8 | 0 |
| Alopecia | Very common | 18.5 | 0 |
| Dry skine | Very common | 13 | 0 |
| Dermatitisf | Common | 2.5 | 0 |
| Folliculitis | Common | 1.2 | 0 |
| General disorders and administration site conditions |
| Fatigue | Very common | 37.7 | 1.9* |
| Investigations |
| Alanine aminotransferase increased | Very common | 17.3 | 3.7* |
| Weight decreased | Very common | 17.3 | 3.7* |
| Blood insulin increased | Common | 6.2 | 0 |
| Grading according to CTCAE version 5.0. * No Grade 4 events were observed. a Includes hyperglycaemia, blood glucose increased, hyperglycaemic crisis, glycated serum protein increased, glucose tolerance impaired, diabetes mellitus, Type 2 diabetes mellitus, and glycosylated haemoglobin increased. b Adverse reaction reported during post-marketing experience. The frequency category was estimated as the upper limit of the 95% confidence interval calculated on the basis of the total number of patients exposed to Itovebi in clinical trials. c Includes aphthous ulcer, glossitis, glossodynia, lip ulceration, mouth ulceration, mucosal inflammation, and stomatitis. d Includes rash, rash erythematous, rash maculo-papular, rash papular, rash pruritic, and rash pustular. e Includes dry skin, skin fissures, xerosis, and xeroderma. f Includes dermatitis, dermatitis acneiform, and dermatitis bullous. |
Description of selected adverse drug reactions
Hyperglycaemia
In the INAVO120 study, hyperglycaemia of any grade was reported in 59.9% of patients treated with Itovebi in combination with palbociclib and fulvestrant; Grade 2 and Grade 3 events were reported in 38.3% and 5.6% of patients, respectively (based on CTCAE version 5.0). Among the patients who experienced hyperglycaemia, the rate of new onset of hyperglycaemia events was highest during the first two months of treatment with a median time to first onset of 7 days (range: 2 to 955 days).
In the 97 patients who received Itovebi in combination with palbociclib and fulvestrant and experienced hyperglycaemia, 74.2% (72/97) received anti‑hyperglycaemic medicines including SGLT2 inhibitors, thiazolidinediones, and DPP‑4 inhibitors for prophylaxis or treatment of hyperglycaemia. All patients who received anti-hyperglycaemic medicines received metformin as a single agent or in combination with other anti‑hyperglycaemic medicines (i.e., insulin, DPP‑4 inhibitors, and sulfonylureas); and 11.3% (11/97) received insulin (see section 4.4).
In patients with fasting glucose levels > 160 mg/dL (> 8.9 mmol/L) with at least one level (see Table 2) improvement in fasting blood glucose levels (n=52), the median time to improvement was 8 days (range: 2 to 43 days).
Hyperglycaemia led to interruption of Itovebi in 27.8%, to dose reduction of Itovebi in 2.5%, and to discontinuation of Itovebi in 1.2% of patients.
Stomatitis
Stomatitis was reported in 51.2% of patients treated with Itovebi in combination with palbociclib and fulvestrant; Grade 1 events were reported in 32.1% of patients, Grade 2 events in 13.6% of patients, and Grade 3 events in 5.6% of patients. Among patients who experienced stomatitis, the median time to first onset was 13 days (range: 1 to 610 days).
Stomatitis led to interruption of Itovebi in 9.9%, to dose reduction of Itovebi in 3.7%, and to discontinuation of Itovebi in 0.6% of patients.
In patients who received Itovebi in combination with palbociclib and fulvestrant, 24.1% used a mouthwash containing dexamethasone for management of stomatitis (see section 4.4).
Diarrhoea
Diarrhoea was reported in 48.1% of patients treated with Itovebi in combination with palbociclib and fulvestrant; Grade 1 events were reported in 27.8% of patients, Grade 2 events in 16.7% of patients, and Grade 3 events in 3.7% of patients. Among patients who experienced diarrhoea, the median time to first onset was 15 days (range: 2 to 602 days).
Diarrhoea led to interruption of Itovebi in 6.8%, to dose reduction of Itovebi in 1.2%, and did not lead to discontinuation of Itovebi in any patients.
Anti-diarrhoeal medicines (e.g., loperamide) were used in 28.4% of patients who received Itovebi in combination with palbociclib and fulvestrant to manage symptoms.
Elderly
Analysis of the safety of Itovebi comparing patients ≥ 65 years of age (14.8%) to younger patients (85.2%) suggests a higher incidence of Itovebi dose modification/interruptions (79.2% versus 68.1%).
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme Website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.