Table 3 Selected triplet combinations targeting ER, CDK4/6, and PI3K/AKT/mTOR.

From: Emerging systemic therapy options beyond CDK4/6 inhibitors for hormone receptor-positive HER2-negative advanced breast cancer

 

TRINITI-1

IPATUNITY 150

NCT03006172

NCT02684032

N

104

20

36 for arms E and F

103; 59 for arms C and D

Phase

I/II

Ib/III

I/Ib

Ib (dose expansion)

Cohort details

HR+/HER2- ABC after progression on CDK4/6i

HR+/HER2- ABC after progression on first-line ET or primary endocrine-resistant

Primary endocrine-resistant, PIK3CA-mutated, HR+/HER2− ABC

Previously treated HR+/HER2−ABC; CDK4/6i-pretreated for arms C and D

Treatment arm

Exemestane + ribociclib + everolimus

Fulvestrant + palbociclib + ipatasertib

Fulvestrant + palbociclib + inavolisib

Fulvestrant + palbociclib + inavolisib + metformin (obese/prediabetic)

Fulvestrant + palbociclib + gedatolisib (weekly)(arm C)

Fulvestrant + palbociclib + gedatolisib (3weeks on, 1 week off)(arm D)

ORR (%) (95% CI)

8.4 (3.7–15.9)

55 (32–77)

40

13

32 (16–52)

63 (42–81)

CBR (%) (95% CI)

41.1 (31.1–51.6)

95

58%

79 (59–92)

96 (81–100)

Median PFS (months) (95% CI)

5.7 (3.6–9.1)

Not mature

Not reported

5.1 (3.4–7.5)

12.9 (7.4–16.7)

AEs, % (All/≥ grade 3)

    

 Neutropenia

69.2/51.0

75/65

85/65

56/56

66/56

81/67

 Stomatitis

40.4/2.9

40/0

80/10

50/0

88/22

89/22

 Diarrhea

27.9/1.9

80/15

45/5

50/0

31/6

52/7

 Hyperglycemia

18.3/6.7

~20/0

60/15

69/44

25/9

26/7

Reference

Bardia et al.77

Oliveira et al.159

Bedard et al.160

Layman et al.161

  1. AI aromatase inhibitor, CDK4/6i cyclin-dependent kinase 4/6 inhibitor, CBR clinical benefit rate, DCR disease control rate, ET endocrine therapy, ORR objective response rate, PFS progression-free survival.