What the label lists and what reports show
Trilaciclib side effects
Trilaciclib's FDA label: “The most common adverse reactions (≥10% of patients with ≥2% difference in incidence compared to placebo) were fatigue, hypocalcemia, hypokalemia, hypophosphatemia, aspartate aminotransferase increased, headache, and pneumonia.” FAERS holds 241 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is dyspnoea (19 reports).
- No generic listed
Check it at the source: the trilaciclib FDA label on DailyMed (effective August 31, 2025, Pharmacosmos Therapeutics Inc.); the FDA FAERS public dashboard.
What does the label list?
From the label: adverse reactionsThe most common adverse reactions (≥10% of patients with ≥2% difference in incidence compared to placebo) were fatigue, hypocalcemia, hypokalemia, hypophosphatemia, aspartate aminotransferase increased, headache, and pneumonia.
Table 3: Adverse Reactions in ≥5% Patients with SCLC Receiving COSELA (with ≥2% Higher Incidence in COSELA Compared to Placebo)
| Reaction | All Grades a (%) | Grade ≥3 (%) | All Grades a (%) | Grade ≥3 (%) |
|---|---|---|---|---|
| Fatigue | 34 | 3 | 27 | 2 |
| Hypocalcemia b | 24 | <1 | 21 | <1 |
| Hypokalemia c | 22 | 6 | 18 | 3 |
| Hypophosphatemia d | 21 | 7 | 16 | 2 |
| Aspartate aminotransferase increased e | 17 | <1 | 14 | <1 |
| Headache | 13 | 0 | 9 | 0 |
| Pneumonia | 10 | 7 | 8 | 7 |
| Rash | 9 | <1 | 6 | 0 |
| Infusion-related reaction | 8 | 0 | 2 | 0 |
| Edema peripheral | 7 | 0 | 4 | <1 |
| Abdominal pain upper | 7 | 0 | 3 | 0 |
| Thrombosis | 7 | 3 | 2 | 2 |
| Hyperglycemia | 6 | 2 | 3 | 0 |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following clinically significant adverse reactions are described elsewhere in the label: Injection-Site Reactions, including phlebitis and thrombophlebitis [ s ee Warnings and Precautions ( 5.1 )] Acute Drug Hypersensitivity Reactions [see Warnings and Precautions ( 5.2 )] ILD/Pneumonitis [see Warnings and Precautions ( 5.3 )] The most common adverse reactions (≥10% of patients with ≥2% difference in incidence compared to placebo) were fatigue, hypocalcemia, hypokalemia, hypophosphatemia, aspartate aminotransferase increased, headache, and pneumonia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Pharmacosmos at 1-888-828-0655 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. The safety of COSELA was evaluated in Studies 1, 2, and 3 [see Clinical Studies ( 14 )]. Patients received COSELA 240 mg/m 2 by 30-minute intravenous infusion prior to chemotherapy on each chemotherapy day.
Source: FDA drug label, Pharmacosmos Therapeutics Inc., effective August 31, 2025 (SPL set b3179c19-78f3-4bf1-b73e-7f7638522ab1), via openFDA; the full label on DailyMed
What do FAERS reports show?
241 reports list trilaciclib among the medicines taken, each a report of something that happened, not proof the medicine caused it; 25 are coded as a death and 78 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 22 reactions below, 7 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Trilaciclib: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions