8.1 Adverse Reaction Overview
The most frequently reported Treatment emergent Serious Adverse Events (TESAEs) in the tafamidis 80 mg, 20 mg and placebo groups respectively were condition aggravated (22.7%, 23.9% and 32.8%); cardiac failure (19.3%, 18.2%, and 22.6%), cardiac failure congestive (11.9%, 15.9% and 17.5%), cardiac failure acute (13.1%, 4.5% and 9.6%), fall (5.1%, 5.7% and 2.8%) and syncope (3.4%, 0%, 5.6%).
Treatment emergent Adverse Events (TEAEs) with a higher incidence in the tafamidis 80 mg and 20 mg treatment group than placebo (≥2x placebo and reported by ≥4 patients) respectively, included cystitis (3.4%, 2.3% and 0%), sinusitis (5.7%, 5.7% and 0.6%), asthenia (10.2%, 12.5% and 6.2%), balance disorder (8.5%, 2.3% and 1.1%) and cataract (5.1%, 3.4% and 1.1%).
8.2 Clinical Trial Adverse Reactions
Clinical trials are conducted under very specific conditions. The adverse reaction rates observed in the clinical trials; therefore, may not reflect the rates observed in practice and should not be compared to the rates in the clinical trials of another drug. Adverse reaction information from clinical trials may be useful in identifying and approximating rates of adverse drug reactions in real-world use.
The data across clinical trials reflect exposure of 377 ATTR‑CM patients to either 20 mg or 80 mg (administered as four 20 mg capsules) of VYNDAQEL daily for an average of 24.5 months (ranging from 1 day to 111 months). The population included adult patients diagnosed with ATTR‑CM with baseline NYHA (New York Heart Association) Class I, Class II or Class III respectively at 9.1%, 61.4%, and 29.5% in the pooled tafamidis arm and at 7.3%, 57.1% and 35.6%, respectively on placebo. The mean age was approximately 75 years (ranging from 46 years to 91 years of age); >90% were male, and approximately 82% were Caucasian (see Study Results Table 6: Patient Demographics and Baseline Characteristics).
Adverse events were assessed from ATTR‑CM clinical trials with VYNDAQEL including a 30‑month placebo‑controlled trial in patients diagnosed with ATTR‑CM. The frequency of adverse events in patients treated with VYNDAQEL 20 mg (n=88) or 80 mg (n=176; administered as four 20 mg capsules) was comparable to placebo (n=177). Listed below are all causality adverse events reported in the pivotal clinical trial.
A similar proportion of VYNDAQEL‑treated patients compared to placebo discontinued due to an adverse event in the 30‑month placebo‑controlled trial in patients diagnosed with ATTR‑CM [12 (6.8%), 5 (5.7%), and 11 (6.2%)] from the tafamidis meglumine 80 mg, tafamidis meglumine 20 mg, and placebo groups, respectively].
Table 2 Most common (≥10%) Treatment-Emergent Adverse Events reported at higher rate in the tafamidis 20 mg and/or 80 mg groups than in the placebo group (All Causality)
System Organ Class Preferred Term | Tafamidis 20 mg N=88 n (%) | Tafamidis 80 mg N=176 n (%) | Placebo N=177 n (%) |
Cardiac disorders |
atrial fibrillation | 16 (18.2%) | 35 (19.9%) | 33 (18.6%), |
cardiac failure | 30 (34.1%) | 46 (26.1%) | 60 (33.9%) |
cardiac failure acute | 4 (4.5%) | 24 (13.6%) | 17 (9.6%) |
cardiac failure congestive | 17 (19.3%) | 22 (12.5%) | 33 (18.6%) |
General disorders and administration site conditions |
asthenia | 11 (12.5) | 18 (10.2) | 11 (6.2) |
edema peripheral | 17 (19.3) | 30 (17.0) | 31 (17.5) |
Infections and infestations |
bronchitis | 9 (10.2) | 21 (11.9) | 19 (10.7) |
pneumonia | 10 (11.4) | 23 (13.1) | 17 (9.6) |
Injury, poisoning and procedural complications |
fall | 27 (30.7) | 43 (24.4) | 41 (23.2) |
Musculoskeletal and connective tissue disorders |
muscle spasms | 10 (11.4) | 15 (8.5) | 14 (7.9) |
pain in extremity | 6 (6.8) | 27 (15.3) | 20 (11.3) |
Psychiatric disorders |
insomnia | 12 (13.6) | 20 (11.4) | 22 (12.4) |
Renal and urinary disorders |
hematuria | 10 (11.4) | 10 (5.7) | 17 (9.6) |
Respiratory, thoracic and mediastinal disorders |
Cough | 16 (18.2) | 21 (11.9) | 30 (16.9) |
Vascular disorders |
hypotension | 12 (13.6) | 19 (10.8) | 19 (10.7) |
The reported incidence of hypothyroidism was 6.8%, 5.7% and 5.6% in patients in the tafamidis 80 mg, 20 mg and placebo groups, respectively.
8.4 Abnormal Laboratory Findings: Hematologic, Clinical Chemistry and Other Quantitative Data
The incidence of thyroxine abnormality <0.8 x LLN was greater in the tafamidis 80 mg group (29.7%) than in the tafamidis 20 mg (12.3%) and placebo (4.5%) groups. No clinically meaningful shifts in free thyroxine or thyroid stimulating hormone values were observed, and no corresponding signal in thyroid dysfunction was observed in the analysis of TEAEs (see 8.2 Clinical Trial Adverse Reactions for rates of hypothyroidism reported in clinical trials).
Low neutrophil count (<0.8 x LLN) was more frequent with tafamidis treatment than with placebo (1.9% tafamidis 80 mg, 1.2% tafamidis 20 mg, 0.6% placebo).
Elevated liver function tests were more frequent in the tafamidis 80 mg group (3.4%) than in the tafamidis 20 mg (2.3%) and placebo (1.1%) groups.