Myeloprotective Effects of Trilaciclib Among Patients with Small Cell Lung Cancer at Increased Risk of Chemotherapy-Induced Myelosuppression: Pooled Results from Three Phase 2, Randomized, Double-Blind, Placebo-Controlled Studies

Figures & data

Table 1 Distribution of Risk Factors for FN, and Anemia or RBC Transfusions by Treatment Group

Risk Category, n (%)	Trilaciclib (n=123)	Placebo (n=119)
FN
No risk factors	32 (26.0)	35 (29.4)
1/2 risk factors	85 (69.1)	77 (64.7)
3/4 risk factors	6 (4.9)	7 (5.9)
5/6 risk factors	0	0
Chi-square P-value*	0.7632
Anemia or RBC transfusions
No risk factors	48 (39.0)	47 (39.5)
1/2 risk factors	68 (55.3)	62 (52.1)
3/4 risk factors	7 (5.7)	10 (8.4)
Chi-square P-value*	0.6870

Note: *Calculated to test the treatment-by-risk-category association.

Abbreviations: FN, febrile neutropenia; RBC, red blood cell.

Table 2 Myeloprotective Effects According to Age Subgroups

	ITT Population			Age <65 Years		Age ≥65 Years
	Trilaciclib (n=123)	Placebo (n=119)	P-value	Trilaciclib (n=66)	Placebo (n=61)	Trilaciclib (n=57)	Placebo (n=58)
Mean DSN in cycle 1, days (SD)*	0 (1.8)	4 (5.1)	P<0.001	0 (1.7)	3 (4.5)	0 (2.1)	5 (5.6)
Patients with SN, n (%)*	14 (11.4)	63 (52.9)	P<0.001	7 (10.6)	26 (42.6)	7 (12.3)	37 (63.8)
				Treatment-by-age-group interaction P=0.3765^†
Patients with grade 3/4 decreased hemoglobin, n (%)	25 (20.3)	38 (31.9)	P=0.0279	12 (18.2)	16 (26.2)	13 (22.8)	22 (37.9)
				Treatment-by-age-group interaction P=0.6957^†
Patients with RBC transfusions on/after week 5, n (%)	18 (14.6)	31 (26.1)	P=0.0252	8 (12.1)	11 (18.0)	10 (17.5)	20 (34.5)
				Treatment-by-age-group interaction P=0.6791^†
Number of RBC transfusions on/after week 5, event rate (per week)	0.015	0.031	P=0.0027	0.011	0.018	0.019	0.045

Notes: *Primary endpoint; two-sided P-value for treatment effect. ^†A nonsignificant treatment-by-age-group interaction indicates that trilaciclib benefits were comparable in both age groups.

Abbreviations: DSN, duration of severe (grade 4) neutropenia; ITT, intention-to-treat; RBC, red blood cell; SD, standard deviation; SN, severe (grade 4) neutropenia.

Table 3 FN Risk Category Results

	ITT Population		FN Risk Category
			0		1/2		3/4
	Trilaciclib	Placebo	Trilaciclib	Placebo	Trilaciclib	Placebo	Trilaciclib	Placebo
Mean DSN in cycle 1, days (SD)	0 (1.8)	4 (5.1)	0 (1.2)	2 (3.8)	1 (2.1)	5 (5.1)	0 (0.8)	9 (7.5)
Patients with SN, n (%)	14 (11.4)	63 (52.9)	2 (6.3)	11 (31.4)	11 (12.9)	46 (59.7)	1 (16.7)	6 (85.7)

Abbreviations: DSN, duration of severe (grade 4) neutropenia; FN, febrile neutropenia; ITT, intention-to-treat; SD, standard deviation; SN, severe (grade 4) neutropenia.

Figure 1 Subgroup analysis of (A) DSN in cycle 1 and (B) percentage of patients with SN by risk factor and category.

Note: *Trilaciclib minus placebo.

Abbreviations: CI, confidence interval; DSN, duration of severe (grade 4) neutropenia; FN, febrile neutropenia; NE, not estimable (statistical model did not converge); RRR, relative risk reduction; SN, severe (grade 4) neutropenia.

Table 4 Anemia/RBC Transfusions Risk Category Results

	ITT Population		Anemia Risk Category
			0		1/2		3/4
	Trilaciclib	Placebo	Trilaciclib	Placebo	Trilaciclib	Placebo	Trilaciclib	Placebo
Patients with grade 3/4 decreased hemoglobin levels, n (%)	25 (20.3)	38 (31.9)	4 (8.3)	7 (14.9)	18 (26.5)	25 (40.3)	3 (42.9)	6 (60.0)
Patients with RBC transfusions on/after week 5, n (%)	18 (14.6)	31 (26.1)	1 (2.1)	6 (12.8)	14 (20.6)	19 (30.6)	3 (42.9)	6 (60.0)
Total number of RBC transfusions on/after week 5, event rate per week	0.015	0.031	0.003	0.012	0.020	0.033	0.045	0.142

Abbreviations: ITT, intention-to-treat; RBC, red blood cell.

Figure 2 Subgroup analysis of (A) percentage of patients with grade 3/4 anemia, (B) percentage of patients with RBC transfusions on/after week 5, and (C) total number of RBC transfusions on/after week 5 by risk factor and category.

Abbreviations: CI, confidence interval; ECOG PS, Eastern Cooperative Oncology Group performance status; ESA, erythropoiesis-stimulating agent; NE, not estimable (statistical model did not converge); RBC, red blood cell; RRR, relative risk reduction.

Figure 3 Subgroup analysis of TTCD.

Abbreviations: CI, confidence interval; FACT-An, Functional Assessment of Cancer Therapy–Anemia; HR, hazard ratio; NE, not evaluable; TOI, trial outcome index; TTCD, time to confirmed deterioration.