Substantial Burden of Myelosuppression With Trilaciclib and Chemotherapy for ES-SCLC

Use of trilaciclib prior to chemotherapy demonstrated a substantial burden of myelosuppressive hematologic adverse events within the patients with extensive-stage small-cell lung cancer.

Trilaciclib (Cosela) use prior to chemotherapy was associated with a 50% reduction in patients with grade ≥ 3 myelosuppressive hematologic adverse events (HAEs) in at least 1 blood cell lineage as well as a 74% reduction of all-cause hospitalizations compared to patients who received chemotherapy alone, according to a press release from G1 Therapeutics, Inc.1

Results come from the retrospective, observational study describing the substantial burden of myelosuppression and its impact on healthcare resource utilization (HCRU) in patients with extensive-stage small-cell lung cancer (ES-SCLC).

“The real-world burden of myelosuppressive hematologic adverse events among patients receiving chemotherapy, and the resulting hospitalizations, are routinely underestimated in the community oncology setting,” said Jeffrey Scott, MD, chief medical officer of Integra Connect and lead author of the study, in the press release.”

The study enrolled a total of 3,277 patients who were administered chemotherapy alone. A secondary analysis of 21 patients focused on those who received trilaciclib prior to chemotherapy, including 17 who received trilaciclib in the real-world setting. Patients were followed from the date of chemotherapy initiation until death, loss to follow-up, or end of study.2

Of the patients enrolled, the median age for chemotherapy-treated patients was 68 compared to 70 for those treated with chemotherapy and trilaciclib. The majority of the patients in both groups were White (60.1, 76.2), and an ECOG performance status of between 0-3.

A total of 40 patients (65.7%) of the chemotherapy-treated patients receive chemotherapy alone, with most, 70.3%, receiving etoposide and carboplatin as the index regimen. Approximately 34.3% received chemotherapy in addition to immunotherapy, with 89.3% receiving etoposide, carboplatin, and atezolizumab (Tecentriq) together.

“In this retrospective analysis, nearly 60% of patients receiving chemotherapy alone had a grade ≥ 3 myelosuppressive HAE in at least one lineage, with a sizable proportion having multilineage (≥ 2 lineages) myelosuppression. Importantly, these data also capture the first real-world experience of using trilaciclib prior to chemotherapy. Among those patients, the use of trilaciclib nearly eliminated not only grade ≥ 3 HAEs associated with multilineage myelosuppression but also all-cause hospitalizations, added Scott.

At least 1 grade ≥ 3 myelosuppressive HAE was seen in 57.4% of all patients with ES-SCLC treated with chemotherapy. This included 44.6% with grade ≥ 3 neutropenia, 34.0% with grade ≥ 3 anemia, and 33.3% with grade ≥ 3 thrombocytopenia. Additionally, 19.6–23.0% had grade ≥ 3 HAEs in 2 or more lineages, and 14.5% had grade ≥ 3 HAEs.

In chemotherapy-treated patients with ES-SCLC, grade ≥ 3 myelosuppressive HAEs were observed across all index regimens with a 28–49% incidence of grade 3 anemia, 17–47% incidence of grade ≥ 3 neutropenia, and 11–41% incidence of grade ≥ 3 thrombocytopenia.

In regard to health care resource utilization, 83.9% (n = 2751) of the chemotherapy-treated patients with ES-SCLC, received a long-acting (LA) G-CSF, with 61.1% (n = 2003) receiving it within 3 days after the index date. Additionally, 10.7% (n = 352) received RBC transfusions, 7.4% (n = 242) patients were hospitalized between days 8 and 16 post index, and 18.8% (n = 617) reported hospital visits between days 1 and 21 post index.

Among the 2751 patients who received LA G-CSF, 30.3% reported to have grade ≥ 3 anemia as well as grade ≥ 3 myelosuppressive HAE. This includes 14.3% with grade ≥ 3 anemia, 19.0% with grade ≥ 3 neutropenia, and 4.8% with grade ≥ 3 thrombocytopenia. A total of 37.0% (n = 476) patients who received erythropoiesis-stimulating agents had grade ≥ 3 neutropenia and 51.9% had grade ≥ 3 thrombocytopenia.

Of the 21 patients who were given chemotherapy in addition to trilaciclib, 15 (71.4%) received LA G-CSF with 10 of these patients receiving it 3 days after the index date (47.6%). One patient (4.8%) received RBC transfusions, and no patients were reported to have received platelet transfusions at any time after the index date. Additionally, no patients were hospitalized between days 8 and 16 post index, however, 1 (4.8%) was hospitalized between days 1 and 21 post index.

Overall, the findings of the study demonstrate a substantial burden of myelosuppressive HAEs within the patients treated with chemotherapy in addition to immunotherapy for ES-SCLC.

  1. New real-world data show potential of trilaciclib to reduce substantial burden of myelosuppression in patients with extensive-stage small-cell lung cancer treated with chemotherapy. News Release. G1 Therapeutics; Accessed April 1, 2022.
  2. Scott J, Slack D, Gingras L et al. Burden of myelosuppression among all patients with extensive-stage small cell lung cancer treated with chemotherapy in a community oncology setting. Presented at NCCN Annual Conference 2022.