1. Hormone therapy for metastatic breast cancer in 2016
Angelo Di Leo
“Sandro Pitigliani”
Medical Oncology Department
Hospital of Prato
Istituto Toscano Tumori,
Prato, Italy

2. Conflict of Interest Disclosure
Applicability
Company
(1) Advisory role
Yes
AstraZeneca, Bayer, Lilly, Novartis, Pfizer, Roche 　
(2) Stock ownership/profit　
None
(3) Patent royalties/licensing fees　
(4) Lecture fees
AstraZeneca, Eisai, Genomic Health, Novartis, Pfizer, Roche
(5) Manuscript fees
(6) Scholarship fund
(7) Other remuneration

3. Recommendations from the American Society of Clinical Oncology
“ Endocrine therapy, rather than chemotherapy, should be offered as the standard first-line treatment for patients with HR+ advanced breast cancer, except for immediately life threatening disease or if there is concern regarding endocrine resistance ”
Partridge AH et al, J Clin Oncol 32:3307 – 29, 2014

4. Recommendations from the ESO-ESMO ABC-2 panel
“Endocrine therapy is the preferred option for hormone receptor positive disease, even in the presence of visceral disease, unless there is concern or proof of endocrine resistance, or there is disease needing a fast response”
Level of evidence IA
Votes: 100% yes, 29 voters (of 43 members)
Cardoso F et al, The Breast 23:489 – 502, 2014, and Ann Oncol 2014

5. Current criteria used to support 1° line treatment choices in ER+/HER-2 negative advanced breast cancer
In favour of chemotherapy
Uncertain
In favour of endocrine therapy
Disease-free interval
< 1 yr.
1-2 yrs.
> 2 yrs.
Visceral mets.
Massive burden (visceral crisis)
Moderate burden
Minimal burden or absence
Symptoms
Heavy
Moderate
Minimal or absence

6. Evidence supporting the use of Fulvestrant at full doses

7. CONFIRM: a phase III trial comparing Fulvestrant 250 mg vs 500 mg in post-menopausal women with ER + advanced disease

8. Primary endpoint: progression-free survival
1.0
Proportion of patients progression-free
Fulvestrant 500 mg Fulvestrant 250 mg
0.8
HR = 0.80; 95% CI: 0.68, 0.94; p=0.006
0.6
Median PFS (months)
Fulvestrant 500 mg 6.5
Fulvestrant 250 mg 5.5
0.4
0.2
0.0 4 8 12 16 20 24 28 32 36 40 44 48
Time (months)
Patients at risk: 500 mg 250 mg
113 85
90 60
54 35
37 25
19 12
12 4
7 3
3 1
2 1
0 0
CI, confidence interval; HR, hazard ratio; PFS, progression-free survival
Di Leo A et al. J Clin Oncol 2010; 28: 8

9. Secondary endpoint: overall survival (first analysis at 50% maturity – full analysis set)
1.0
Proportion of patients alive
Fulvestrant 500 mg Fulvestrant 250 mg
0.8
HR = 0.84; 95% CI: 0.69, 1.03; p=0.091
0.6
0.4
Median time to death (months)
Fulvestrant 500 mg
Fulvestrant 250 mg
0.2
0.0 4 8 12 16 20 24 28 32 36 40 44 48
Time (months)
Patients at risk: 500 mg 250 mg
74 61
46 34
29 18
16 10
6 2
0 0
Di Leo A et al. J Clin Oncol 2010; 28: 9

10. Overall survival (final analysis at 75% maturity – full analysis set)
Proportion of patients alive
1.0
Fulvestrant 500 mg
0.9
Fulvestrant 250 mg
0.8
HR (95% CI)
0.81 (0.69, 0.96)
p-value
0.016a
0.7
0.6
0.5
aNominal value, cannot be claimed as statistically significant
0.4
0.3
Median time to death (months)
Fulvestrant 500 mg 26.4
Fulvestrant 250 mg 22.3
0.2
0.1 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72 76 80
Time (months)
Patients at risk:
362
333
288
254
227
202
178
163
141
123
114 98 81 64 47 30 26 15 8 1
500 mg
374
338
299
261
223
191
164
137
112 96 87 74 64 48 37 22 14 8 3 2
250 mg
Di Leo A et al, J Natl Cancer Inst, 2014; 106 (1): djt337

11. Overall survival: first (50% events) and final (75% events) analyses

12. Summary of patients who had at least one SAE during the whole treatment period (main trial plus follow-up phase)
Number (%) of patients
Fulvestrant 500 mg
N=361
Fulvestrant 250 mg
N=374
Any SAE
35 (9.7)
27 (7.2)
Any causally related SAE
8 (2.2)
4 (1.1)
All events occurring after first dose are summarized Patients with multiple events in the same category were counted only once in that category Patients with events in more than one category were counted once in each of those categories 12

13. SAEs with outcome of death during the whole treatment period
Preferred term
Number (%) of patients
Fulvestrant 500 mg N=361
Fulvestrant 250 mg N=374
Acute myocardial infarction
2 (0.5)
Acute renal failure
1 (0.3)
Aspiration
Cardiopulmonary failure
Completed suicide
Death (death cause unknown)
Dyspnea
2 (0.6)
Hypertension
Intestinal adenocarcinoma
Meningitis
All events occurring after first dose are summarized Patient numbers are not mutually exclusive 13

14. Primary end-point = clinical benefit (CB) rate
Previous data from phase II randomised studies testing Fulvestrant 500 mg: the FIRST trial
anastrozole 1 mg/daily (N=103)
post-menopausal
ER+ advanced, 1st line
fulvestrant 500 mg days 0, 14, 28, and then q 28 days (N=102)
Primary end-point = clinical benefit (CB) rate F A
No. CR (%) -
1 (1)
No. PR (%)
32 (31)
No. NC ≥ 24 wks (%)
42 (41)
36 (35)
No. CB (%)
74 (72)
69 (67)
Robertson JFR et al, J Clin Oncol 2009

15. Updated TTP data from phase II randomized studies testing Fulvestrant 500 mg: the FIRST trial
Robertson JFR et al, Breast Cancer Res Treat 2012

16. Robertson JF et al, J Clin Oncol, 33(32):3781-7, 2015

18. Cooperation between ER and Cyclic D1 pathways enhances proliferation in luminal breast cancer
Cyclin D1 ER
Inhibitory control
Inhibitory control
p Rb
CDK4-6
Cell Cycle:
G S
Inhibitors:
Palbociclib
Abemaciclib
Ribociclib
proliferation

19. Considerations on CDK4/6 inhibitor activity
PD has shown activity preferentially on ER+, luminal breast cancer cell lines with or without HER2 amplification.
IC50 nM
Subtype
Luminal
Non -
luminal/post EMT
HER2 Amplified
luminal
Immortalized
RB1, cyclin D1, and CDKN2A (p16) were differentially expressed - with higher levels of RB1 and cyclin D1, and lower levels of p16, in the sensitive group.
Resistance to PD in many of the nonluminal breast cancer cell lines may be explained by the absence of pRb. Recent publications highlighted the lack of pRb in basal-like breast cancer tissue and observed that pRb depletion can result in the characteristic epithelial-to-mesenchymal transition changes
The lack of activity of a CDK4/6 inhibitor in cell lines and tumors that lack pRb can be explained by the fact that cyclin D1 does not offer G1 control in the absence of pRb.
Finn et al, BCR 2011 19

27. PALOMA-3: Study design N=521c
Palbociclib
(125 mg QD; 3 wks on/1 wk off)
+ Fulvestrantd (500 mg IM q4w)
HR+ HER2– ABC
Pre-/peri-a or postmenopausalb
Progressed on prior endocrine therapy:
On or within 12 mo of completion of adjuvant treatment
On or within 1 mo of treatment for ABC
≤1 prior chemotherapy regimen for advanced cancer
n=347
2:1 randomisation
N=521c
Stratification:
Placebo (3 wks on/1 wk off)
+ Fulvestrantd (500 mg IM q4w)
Visceral metastases
Sensitivity to prior hormonal therapy
Pre-/peri- vs. postmenopausal
ABC3 Dr Crown
n=174
aAll received goserelin.
bMust have progressed on prior endocrine therapy (pre-/perimenopausal) or aromatase inhibitor therapy (postmenopausal).
cPatients randomised.
dAdministered on Days 1 and 15 of Cycle 1, then every 28 d.
Randomised Phase III double-blind trial at 144 centres in 17 countries (NCT )
Turner NC, et al. N Engl J Med 2015;373:209–19; Turner NC, et al. ASCO 2015 (Abstract LBA502); 27

28. PALOMA-3: Updated investigator-assessed PFS (ITT)
100
PAL + FUL (N=347)
PBO + FUL (N=174)
Median PFS, months (95% CI)
9.5 (9.2, 11.0)
4.6 (3.5, 5.6)
Hazard ratio (95% CI)
0.461 (0.360, 0.591)
1-sided p-value
< 80 60
PFS (%)
Palbociclib + fulvestrant
Placebo + fulvestrant 40 20
Figure 2a 2 4 6 8 10 12 14
Time (months)
Number of patients at risk
PAL+FUL
PBO+FUL
Turner NC, et al. N Engl J Med 2015;373:209–19; Turner NC, et al. ASCO 2015 (Abstract LBA502); 28

29. PALOMA-3: PFS by menopausal status
Pre-/perimenopausal women
Postmenopausal women
100
100
HR 0.435
P=0.01
HR 0.409 P= 80 80
Palbociclib +
fulvestrant
n=72
Palbociclib +
fulvestrant
n=275 60 60
PFS PROBABILITY (%)
PFS PROBABILITY (%) 40 40 20 20
Placebo +
fulvestrant
n=36
Placebo +
fulvestrant
n=138
5.6 months
9.5 months
3.7 months
9.2 months
ABC3 Dr Crown 2 4 6 8 10 12 2 4 6 8 10 12
TIME (MONTHS)
TIME (MONTHS)
Menopausal status interaction test P=0.94
All pre-/peri-menopausal patients also received goserelin.
Winer EP. ASCO ‘Highlights of the Day: Breast Cancer 29 29

30. PALOMA-3 final analysis: Treatment effect by PIK3CA status
PIK3CA mutations were detected in 33% of patients who provided baseline plasma samples for cell-free DNA analysis (129/395)
PIK3CA status did not influence the magnitude of PFS benefit from palbociclib (HR=0·45 for PIK3CA wild-type, HR=0·48 for PIK3CA mutation positive, Pinteraction = 0·83)
PIK3CA-wild-type patients (n=266)
Patients with PIK3CA mutations (n=129)
Time (months)
PFS (%) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 20 40 60 80
100
180
173
146
141
129
112
110 56 53 17 86 55 52 39 38 31 30 15
Palbociclib + fulvestrant
Placebo + fulvestrant
Number at risk
Placebo + fulvestrant (n=86)
Palbociclib + fulvestrant (n=180)
HR (95% CI)
0.45 (0.31–0.64)
P value
<0.0001 1 2 3 4 5 6 7 8 9 10 11 12 13 14 20 40 60 80
100
HR (95% CI)
0.48 (0.30–0.78)
P value
0.002
Time (months)
PFS (%)
Placebo + fulvestrant (n=44)
Palbociclib + fulvestrant (n=85) 85 82 67 64 56 55 44 23 12 10 2 28 27 20 4 1
Palbociclib + fulvestrant
Placebo + fulvestrant
Number at risk
PFS, progression-free survival; HR, hazard ratio; CI, confidence interval
Cristofanilli M, et al. Lancet Oncol. 2016 30

31. An attempt to move recent trial results into clinical practice
1st line, ER+ HER-2 neg advanced disease, post-menopausal pts.
prior adjuvant HT
Options
Naive
Fulvestrant
Fulvestrant + Palbociclib
TAM
- AI
- AI + Palbociclib - Fulvestrant + Palbociclib (if relapse while on TAM) AI
- Fulvestrant - Fulvestrant + Palbociclib

32. A functional Rb signature
E2F1 and E2F2 high vs low
breast cancers in the TCGA
Expression data
Differential gene expression analysis
Functional RBsig
Correlation with palbociclib activity (in-vitro)
Prognostic value (in-silico analysis)
Migliaccio I et al, Ann Oncol, 2015, 26 (suppl 3): iii15

33. Functional RBsig discriminates sensitive vs resistant BC cell lines
AUC = 0.93
Migliaccio I et al, Ann Oncol, 2015, 26 (suppl 3): iii15

34. RBsig is prognostic in patients with ER+ tumors
Untreated
ER+
Luminal A
Luminal B
Endocrine treated only
Migliaccio I et al, Ann Oncol, 2015, 26 (suppl 3): iii15

35. ESR1 mutations and response to Palbociclib in the PALOMA 3 trial
ESR1 mutated
ESR1 wild type
Fribbens C et al, J Clin Oncol 2016 (June 6, Ahead of print)

36. ESR1 mutations and response to different endocrine therapy agents
ESR1 mutations and response to different endocrine therapy agents. The SOFEA trial results
ESR1 mutated
ESR1 wild type
Fribbens C et al, J Clin Oncol 2016 (June 6, Ahead of print)

37. Clinical trials comparing HT vs
Clinical trials comparing HT vs. HT + biological agent in ER+ advanced disease. Focus on: - The BOLERO-2 trial

38. The BOLERO-2 Phase III trial: Everolimus in advanced disease
EVE 10 mg daily +
EXE 25 mg daily (n = 485)
Placebo
EXE 25 mg daily (n = 239) R
2:1
N = 724
Postmenopausal ER+
Unresectable locally advanced or metastatic BC
Recurrence or progression after letrozole or anastrozole
84% of patients sensitive to prior endocrine therapy (i.e. DFI > 24 mos.
if relapse while/after adjuvant AI or clinical benefit to the prior line of endocrine therapy for advanced disease)
84% of patients received the study drugs as ≥ 2° line of therapy for advanced disease
BOLERO-2 is an acronym for Breast cancer trials of OraL EveROlimus-2. BOLERO-2 is a pivotal, international, multicenter, randomized phase III study evaluating EVE in combination with exemestane (EXE), conducted in postmenopausal women with ER+, refractory, advanced BC (with recurrence or progression after prior therapy with LET or anastrozole [ANA]).
Women (N = 724) were randomized 2:1 to receive either EVE + EXE or placebo + EXE.
Treatment continued until disease progression, unacceptable toxicity, or consent withdrawal. No crossover after disease progression was allowed.
Randomization was stratified by documented sensitivity to prior hormonal therapy (yes vs no) and by the presence of visceral metastasis (yes vs no). Sensitivity to prior hormonal therapy was defined as either (1) documented clinical benefit (complete response, partial response, stable disease ≥ 24 weeks) from at least 1 prior hormonal therapy in the advanced setting or (2) ≥ 24 months of adjuvant hormonal therapy before recurrence.
This study is ongoing and remains blinded; all patients without documented disease progression continue to be followed for progression free survival (PFS). All patients are being followed for overall survival (OS) in a blinded manner, even when they have disease progression and go off study.
Baselga J, et al. N Engl J Med. 366: , 2012 38

39. PFS (based on local assessment at 18 mos. follow-up) and OS
EVE 10 mg + EXE
PBO + EXE
Number of patients still at risk 20 40 60 80
100
Time (week) 6 12 18 24 30 36 42 48 54 66 72 78 84 90 96
102
108
114
120
485
436
366
304
257
221
185
158
124 91 50 35 22 13 10 8 2 1
239
190
132 67 39 21 15 5 3
Censoring times
EVE 10 mg + EXE (n/N = 310/485)
PBO + EXE (n/N = 200/239)
HR = 0.45 (95% CI: )
Log-rank P value: < .0001
Kaplan-Meier medians EVE 10 mg + EXE: 7.8 months
PBO + EXE: 3.2 months
Probability (%) of Event
OS**
HR = 0.89 (95% CI, )
Log-rank P = .14
Kaplan-Meier medians
EVE+EXE: months
PBO+EXE: months
Censoring times
232
109
248
113
266
120
279
130
292
145
311
153
330
162
347
170
373
182
399
194
414
201
429
211
448
220
471
485
239
EVE+EXE
PBO+EXE
No. at risk 11 5 23 8 39 18 58 28 91 41
118 56
154 77
196 98
216
102 1
* Baselga J et al, N Engl J Med. 366: , 2012; ** Piccart M et al, Ann Oncol 25: , 2014

40. Safety profile everolimus: most common adverse events
% G3-G4 (%G1-G4)
Placebo
N = 238
Stomatitis
8 (56)
1 (11)
Anemia
6 (16)
1 (4)
Dyspnea
4 (18)
1 (9)
Hyperglicemia
4 (13)
1 (2)
Fatigue
4 (33)
1 (26)
Pneumonitis
3 (12)
- (-)
Baselga J et al, New Engl J Med 366: 520-9, 2012. 40 40

41. The TAMRAD trial post-menopausal ER+/HER-2 neg No. = 111 pts.
pre-treatment with AI
TAM + Everolimus
TAM
TAM
TAM + Everolimus
Clinical benefit rate at six months
42%
(95% CI: 29-56%)
61%
(95% CI: 47-74%)
Bachelot T et al, J Clin Oncol 30: , 2012

42. Primary resistance Secondary resistance
The TAMRAD trial: TTP results by level of response to prior aromatase inhibitor therapy
Primary resistance
Secondary resistance
Bachelot T et al, J Clin Oncol 30: , 2012

43. An attempt to move recent trial results into clinical practice
Pts. progressing on endocrine therapy + CDK 4-6 inhibitors
chemotherapy
HT + everolimus
HT + everolimus = last attempt of “endocrine therapy” before moving to chemothrapy

44. New agents currently tested in Phase III trials

49. Combined LEE011, Fulvestrant and PI3K Inhibition in ER+ Breast Cancer
Triplet combination therapies of LEE011 with fulvestrant and PI3K inhibitors demonstrate potent tumor regressions in PIK3CA-wild-type and PIK3CA-mutant ER+ breast cancer models
Activity of LEE011 + fulvestrant + PI3Ki in a PIK3CA-mutant ER+ BC model (MCF7)
Activity of LEE011 + fulvestrant + PI3Ki in a PIK3CA-wild-type ER+ BC model (KPL1)
Tumor Volume mm3
Tumor Volume mm3
Triplet combination therapies of LEE011 with fulvestrant and PI3K inhibitors demonstrate potent tumor regressions in PIK3CA wild-type and PIK3CA-mutant ER+ breast cancer models
Reference
1. O’Brien NA, et al. AACR 2014;abst 4756.
PI3Ki, PI3K inhibitor.
1. O’Brien NA, et al. AACR 2014; Abstract 4756 49

50. PI3K Pathway Inhibitors in Clinical Development in Breast Cancer
Drug
Source
Target(s)
GDC-0032
Genentech
PI3Kα
MLN-1117
Millenium
BYL719
Novartis
GS-1101
Gilead
PI3Kd
XL-147/SA245408
Exelixis/Sanofi
Pan-PI3K
BKM120
GDC-0941
PF /PKI-587
Pfizer
XL-765/SAR245409
PI3K/mTOR
BEZ235
GDC-0980
MLN-128/MLN0128
TORC1/2
OSI-027
OSI Pharma
AZD2014
AstraZeneca
AZD5363
AKT (catalytic)
MK2206
Merck
AKT (allosteric)
GDC-0068
ClinicalTrials.gov. From: Accessed August 2013. 50

51. The FERGI trial: a phase II randomised trial
post-menopausal
ER+/HER-2 negative No. = 168 pts.
prior AIs
Fulvestrant 500 mg + Pictilisib
Fulvestrant 500 mg + Placebo
Cross-over allowed !
42% of pts. with PIK3CA mutation
Krop I et al, Lancet Oncol, 17(6):811-21, 2016

52. Krop I et al, Lancet Oncol, 17(6):811-21, 2016

53. Potential (non-mutually exclusive) explanations for the lack of interaction between PIK3CA gene status and clinical activity of PI3K/MTOR inhibitors
Pictilisib is a pan-PI3K inhibitor. Different results with an α-specific PI3K inhibitor?

54. Sensitivity of PIK3CA-mutant breast cancer to single-agent BYL719 in vivo
In vivo, BYL719 shows statistically significant antitumor efficacy in PIK3CA-mutant breast tumor xenograft models
T/C
100%
1.5%
T/C
100%
–62.6%
Vehicle 10 ml/kg po q24h
NVP-BYL719-NX-7 50 mg/kg po q24h
po, per os (by mouth); q24h; once every 24 hours; SEM, standard error of mean; T/C, treatment over control.
Novartis data on file

55. Potential (non-mutually exclusive) explanations for the lack of interaction between PIK3CA gene status and clinical activity of PI3K/MTOR inhibitors
Pictilisib is a pan-PI3K inhibitor. Different results with an α-specific PI3K inhibitor?
PI3K pathway down-stream effectors might be more informative than PIK3CA gene status (Loi S et al, Proc Natl Acad Sci USA 107: , 2010)

56. Potential (non-mutually exclusive) explanations for the lack of interaction between PIK3CA gene status and clinical activity of PI3K/MTOR inhibitors
Pictilisib is a pan-PI3K inhibitor. Different results with an α-specific PI3K inhibitor?
PI3K pathway down-stream effectors might be more informative than PIK3CA gene status (Loi S et al, Proc Natl Acad Sci USA 107: , 2010)
Differences in PIK3CA gene status between the primary and the matched metastatic sites

57. Primary tumor vs. Circulating Tumor Cells (CTC)
vs. circulating tumor DNA (ct DNA)
Analysis of single CTCs, ct DNA and primary tumor tissue from pt 11, pt 12, and pt 18
Pt18
Pt11
ct DNA
ct DNA
Primary
Primary
Pt12
ct DNA
Primary
De Luca F et al, Oncotarget, 2016; 7: 57

58. Baselga J et al, proc. SABCS, 2015

59. Baselga J et al, proc. SABCS, 2015

60. Baselga J et al, proc. SABCS, 2015

61. Baselga J et al, proc. SABCS, 2015

62. Acknowledgments