1. Clinical Updates
Tubulin Inhibition in Breast Cancer: A Therapeutic Target Critical to Improving Outcomes
William J. Gradishar, MD
Professor of Medicine
Robert H. Lurie Comprehensive Cancer Center
Northwestern University Feinberg School of Medicine
Chicago, IL

2. Role of Microtubule in Cellular Physiology
Microtubules, a key component of cell cytoskeleton
comprise filamentous polymers
dynamic structures that depolymerize and rearrange to form mitotic spindle which is essential to cell division
Microtubules
through mitotic spindle, align and separate chromosomes
transport cellular material
engage in intracellular signalling
play integral role in cell growth and mitosis
re-organized in cell invasion and migration, processes essential to tumor metastasis
Biological function of microtubules regulated by polymerization dynamics
McIntosh et al, Microtubules. Wiley-Liss: New York 1994; 413–34; Oakley et al, Microtubules. Wiley-Liss: New York 1994; 33–45 Wordeman et al, Microtubules. Wiley-Liss: New York 1994; 287–301

3. Structure of a Microtubule
Jordan & Kamath, Curr Cancer Drug Targets 2007; 7: 730–42

4. Microtubule Involvement in Mitosis
Jackson et al, Nat Rev Cancer 2007; 7: 107–17 Reprinted by permission from Macmillan Publishers Ltd.

5. Effects of Tubulin-binding Drugs on Microtubules
Jordan et al, Mol Cancer Ther 2005; 4: 1086–95 Verrills & Kavallaris, Curr Pharm Des 2005; 11: 1719–33

6. Taxane-based Therapy Active against a wide spectrum of malignancies
4/6/2017 2:24 PM
Taxane-based Therapy
Active against a wide spectrum of malignancies
Standard component of breast, ovarian, and NSCLC therapy
Limitations with traditional taxanes
Hydrophobic and require solvents
Cremophor® with paclitaxel
Tween 80 with docetaxel
van Zuylen L, et al. Invest New Drugs. 2001;19: ; van Tellingen O, et al. Clin Cancer Res. 1999;5: ; Ellis AG, et al. Cancer Chemother Pharmacol. 1996;38:81-87; LoRusso PM, Pilat MJ. ONS News. 2004;19:75-76. 6

7. Solvent-based Taxane Toxicities
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Reaction
Docetaxel
Paclitaxel
Hypersensitivity reaction (grade 3/4)
2.6%* 2%
Neutropenia (<500 mm3)
85.9%
52%
Leukopenia (<1000 mm3)
43.7%
17%
Thrombocytopenia (<100,000/mm3)
9.2%
20%
Anemia (<11 g/dL)
93.6%
78%
Peripheral neuropathy (grade 3/4)
5.5% 3%
Arthralgia/myalgia (grade 3/4)
10% 8%
Mucositis
7.4%
31%
Cardiovascular events
8.1%
16%
*Regardless of premedication.
Adapted from product inserts of paclitaxel (BMS, n=812)
and docetaxel (Aventis, n=2045). 7

8. Appropriate Clinical Utilization of Novel Taxane Formulations8

9. Improved Taxane Formulations
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Rationale
Decrease hypersensitivity reactions
Avoid solvent toxicities
Improve side effect profiles
Favorable PK
Decrease infusion times
Agents
nab paclitaxel
Paclitaxel poliglumex
Milataxel
DHA-paclitaxel
Paclitaxel tocopherol-based emulsion formulation 9

10. Nanoparticle Albumin Bound (nab) Platform
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Nanoparticle Albumin Bound (nab) Platform
Albumin
IV/IA
Protein
Oral
Active drug
Human albumin
Topical
Proprietary process
Insoluble drug
Inhalational
Stable nanoparticles
~ µm, negatively charged 10

11. Mechanisms of Transport of nab Paclitaxel to Tumors
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Leaky junction
Tumor interstitium
Tumor cell
(A) Enhanced permeation
and retention (EPR) effect
Lumen of tumor microvessel
(C) Tumor uptake
Endothelial cell (EC)
Caveolae and vesicles
Tumor cell
(B) Receptor mediated
EC membrane 11

12. nab Paclitaxel
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First clinical application of albumin-bound nanoparticle (nab) technology (FDA approved: Jan 2005)
Paclitaxel bound to albumin in a nanoparticle
Increases drug selectivity for tumor cells (albumin intake mechanisms)
No routine steroid or antihistamine premedication required, no toxic solvents
In a phase III trial, demonstrated superior efficacy vs paclitaxel in MBC
RR doubled
Prolonged TTP
Improved grade 4 neutropenia/sensory neuropathy
Gradishar WJ, et al, J Clin Oncol. 2005;23: 12

13. Phase III Trial of nab Paclitaxel in MBC
Nab paclitaxel 260 mg/m2
i.v. over 30 min q 3 wk
No standard premedication
Women with measurable stage IV breast cancer
No prior taxane therapy
N = 460 or
Cremophor paclitaxel 175 mg/m2 i.v. over 3 hours q 3 wk
Standard premedication with dexamethasone and antihistamines
Gradishar et al. J Clin Oncol. 2005;23: 13

14. Phase III Trial Albumin-Bound Paclitaxel vs. Paclitaxel in MBC
Albumin-bound paclitaxel: 260 mg/m2 q3w; Paclitaxel:175 mg/m2 q3w
Albumin-Bound Paclitaxel
N=229
Paclitaxel
N=225
P-Value
Overall Response Rate
33%
19%
.001
Time to Progression
23.0 wk
16.9 wk
.006
Grade 4 Neutropenia 9%
22%
<.001
Grade 3 Sensory Neuropathy
10%* 2%
* Median time to improvement: 22 days
Gradishar et al. JCO 23: 7794; 2005 14

15. Phase III Every 3w Hematologic Toxicities
Hematologic toxicity
nab Paclitaxel
n=229
Paclitaxel
n=225
P-Value*
Grade 3
Grade 4
Neutropenia
25% 9%
31%
22%
<0.001
Thrombocytopenia
<1% 0%
0.387
Anemia
0.192
Febrile neutropenia
0.491
Septic deaths --
*Cochran-Mantel-Haenszel test based upon all grades.
Gradishar et al. JCO 23: 7794; 2005 15

16. Randomized Study Comparing
nab-Paclitaxel with Solvent-based Paclitaxel in Chinese Patients with Metastatic Breast Cancer
Zhong-Zhen Guan, M.D.1; Fengyi Feng, M.D.2, Qing Li Li, M.D.3, Zefei Jiang, M.D.4, Zhenzhou Shen, M.D.5, Shiying Yu, M.D.6, Jifeng Fen, M.D.7, Jianjin Huang, M.D.8, Zhiwen Yao, M.D.9, Michael. J. Hawkins, M.D.9 1Sun Yat Sen University Cancer Centre, Guangdong, China; 2Cancer Center of CAMS, Beijing, China; 3Tianjin Tumor Hospital, Tianjin, China; 4PLA 307 Hospital, Beijing, China; 5Fudan University Cancer Center, Shanghai, China; 6Tonghi Hospital, Wuhan, China; 7Jiansu Tumor Hospital, Jiansu, China, 8No. 2 Hospital of Medical College, Zhejiang University, Hangzhou, China, 9Abraxis BioScience, Inc., Los Angeles, CA.

17. Response Rate, Time To Progression, Progression-free Survival, and Overall Survival
nab-paclitaxel
(n =104)
SB-paclitaxel
(n = 106)
P-value
Overall Response Rate
(Complete Response + Partial Response)
56 (54%)
31 (29%)
<0.001*
Median Time To Progression (months)
7.6
6.2
0.078**
95% CI
6.7 to 8.6
4.7 to 8.0
Median Progression-free Survival (months)
0.118**
6.7 to 8.5
For time to progression, 51% of events have occurred
For progression-free survival, 52% of events have occurred
P-value based on CMH test stratified by study site and line of therapy
** P-value based on log rank test

18. Overall Response Rate
By Line of Metastatic Study Drug Therapy and By Prior Anthracycline Therapy
P = .132
P = .001
P< .001
Prior Adjuvant or Metastatic Anthracycline Therapy
Line of Metastatic Therapy
Yes
1st Line No
>1st Line
P = .181
P-value based on CMH test stratified by study site and line of therapy
nab-Paclitaxel
SB-paclitaxel N

19. Comparison of nab Paclitaxel and Docetaxel
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Comparison of nab Paclitaxel and Docetaxel R A N D O M I Z E
1st line MBC patients
(N=300)
Comparisons
nab paclitaxel vs docetaxel (A, B, C vs D)
Weekly vs every-3-weeks nab paclitaxel (B, C vs A)
Low vs high dose weekly nab paclitaxel (B vs C)
Arm A: nab paclitaxel 300 mg/m2 q3w
Arm B: nab paclitaxel 100 mg/m2 weekly 3 out of 4
Arm C: nab paclitaxel 150 mg/m2 weekly 3 out of 4
Arm D: docetaxel 100 mg/m2 q3w
Gradishar W, et al. ASCO Abstract 1032. 19

20. Response Rates for nab Paclitaxel vs. Docetaxel
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70%
70%
60%
62%
50%
40%
43%
Response rate (%)
38%
30%
20%
10% 0%
300 mg/m2 100 mg/m mg/m2 Docetaxel
q3w qw 3/4 qw 3/4 100 mg/m2 q3w (A: n=76) (B: n=76) (C: n=74) (D: n=74)
nab paclitaxel
Gradishar W, et al. ASCO Abstract 1032. 20

21. Pearson Correlation Coefficient (Investigator vs. IRR) = 0.507
Comparison of Investigator and Independent Radiology Review Response Assessments
Pearson Correlation Coefficient (Investigator vs. IRR) = 0.507
Response Rate (%)
300 mg/m2 100 mg/m mg/m2 docetaxel
q3w qw 3/4 qw 3/4 100 mg/m2 q3w (A: n = 76) (B: n = 76) (C: n = 74) (D: n = 74)
nab paclitaxel 21

22. Neutropenia (Based Upon Central Laboratory Data)
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Treatment arm
Grade (%)
Febrile
neutropenia
(%)
P vs docetaxel
P vs (B) I II
III IV
nab paclitaxel
300 mg/m2 q3w (A) 20 29 39 5 1
<0.001
0.007
100 mg/m2 weekly (B) 24 32
150 mg/m2 weekly (C) 15 34 9
0.004
Docetaxel
100 mg/m2 q3w (D) 3 19 75 7
P-values by Cochran-Mantel-Haenszel; includes all grades of toxicity.
Gradishar W, et al. ASCO Abstract 1032. 22

23. Treatment-related Adverse Events Peripheral Neuropathy
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Treatment-related Adverse Events Peripheral Neuropathy
Treatment arm
Grade (%) I II
III IV
P vs docetaxel
P vs (B)
nab paclitaxel
300 mg/m2 q3w (A) 34 21 17
0.140
0.006
100 mg/m2 weekly (B) 33 11 9
0.190
150 mg/m2 weekly (C) 30 20 16
0.345
0.027
Docetaxel
100 mg/m2 q3w (D) 32 19
P-values by Cochran-Mantel-Haenszel; includes all grades of toxicity.
Gradishar W, et al. ASCO Abstract 1032. 23

24. Treatment-related Adverse Events Fatigue
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Treatment-related Adverse Events Fatigue
Treatment Arm
Grade (%) I II
III IV
P vs docetaxel
P vs (B)
nab paclitaxel
300 mg/m2 q3w (A) 7 24 4
0.131
0.018
100 mg/m2 weekly (B) 18 13
150 mg/m2 weekly (C) 20 19 3
0.103
0.015
Docetaxel
100 mg/m2q3w (D) 22 15
P-values by Cochran-Mantel-Haenszel; includes all grades of toxicity.
Gradishar W, et al. ASCO Abstract 1032. 24

25. nab Paclitaxel vs Docetaxel in Taxane-naïve MBC
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nab Paclitaxel vs Docetaxel in Taxane-naïve MBC
Higher overall response rates with weekly nab paclitaxel 100 mg/m2 and 150 mg/m2 compared with docetaxel
nab paclitaxel 150 mg/m2 weekly and 300 mg/m2 every 3 weeks increased PFS compared to docetaxel with an improved safety profile
nab paclitaxel 100 mg/m2 weekly was well tolerated and resulted in PFS comparable to docetaxel
nab paclitaxel 150 mg/m2 weekly produced a longer PFS than nab paclitaxel 100 mg/m2 weekly
Gradishar W, et al. ASCO Abstract 1032. 25

26. Clinical Response to nab Paclitaxel + Capecitabine
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Clinical Response to nab Paclitaxel + Capecitabine
More than 50% of patients achieved at least a partial response
Patient Best Response
Evaluable Patients
(n = 34)
Complete
3 (9%)
Partial
15 (44%)
Stable disease
11 (32%)
Disease progression
5 (15%)
Conclusion: First-line therapy with weekly nanoparticle albumin-bound paclitaxel plus daily capecitabine is active and well tolerated
Schwartzberg LS, et al. SABCS Abstract 1096. 26

27. nab Paclitaxel + Capecitabine Time to Progression (TTP)
25% Quartile for Time to Progression:
133 days Progression-free Survival
0.25
0.5
0.75 1 50
100
150
200
250
300
350
Days from first chemo date
Survival distribution function
Product limited estimate curve
Censored observations
Preliminary data demonstrates prolonged TTP with this combination
Schwartzberg LS, et al. SABCS Abstract 1096.

28. Case #1
A 42-year old woman was diagnosed with stage II, left sided breast cancer in 2005.
Initial therapy included BCS. T= 3 cm; SLNB-negative; ER, PR, HER2- negative.
Adjuvant therapy was TC x (docetaxel, cyclophosphamide) and radiation therapy.

29. Case #1 (cont.)
3 ½ years later she presents with left rib pain. PE reveals a 1 cm left supraclavicular node.
Restaging demonstrates multiple lytic bone lesions and several small lung nodules.
FNA of SCN is positive for adenocarcinoma and appears similar to the original breast cancer.

30. Case #1 (cont.)
Which systemic therapy would you recommend in addition to bisphosphonate (BP) therapy?
Paclitaxel / Bevacizumab
Capecitabine
Paclitaxel / Gemcitabine
nab-Paclitaxel
Doxorubicin

31. Case 1 (cont.) Recommended Approach:
Which systemic therapy would you recommend in addition to bisphosphonate (BP) therapy?
Paclitaxel / Bevacizumab
Capecitabine
Paclitaxel / Gemcitabine
nab-Paclitaxel
Doxorubicin
Recommended Approach:
All options are reasonable.

32. Overcoming Breast Cancer Resistance to Taxanes

33. New Strategies for Resistant Breast Cancer
Taxanes, alone or in combination with anthracyclines, form the mainstay of adjuvant and metastatic breast cancer therapy
Taxane pre-treated recurrent breast cancer is an increasingly important clinical issue
A number of complex mechanisms may generate resistance to established chemotherapies, including taxanes

34. New Strategies for Resistant Breast Cancer
Clinically, taxane cross-resistance and an absence of guidance regarding re-treatment increases the need for novel chemotherapies with differing mechanisms of action
Randomized controlled data demonstrating the activity of the epothilone, ixabepilone, in taxane-resistant and pre- treated patients supports its use in clinical practice

35. Taxane Re-treatment Following Previous Taxane Therapy for MBC
Modest clinical efficacy when taxanes re-introduced in taxane- pre-treated / resistant MBC
- Single-agent taxane, ORR varies between %
Disease-free interval believed important
In studies, there is significant variability in DFI criteria and little correlation between interval and observed response rate
Valero et al, J Clin Oncol 1998; 16: 3362–8 Seidman et al, J Clin Oncol 1996; 14: 1877–84 Yonemori et al, Breast Cancer Res Treat 2005; 89: 237–41
Sawaki et al, Tumori 2004; 90: 36–9
Nishimura et al, Chemotherapy 2005; 51: 126–31 Taguchi et al, Breast J 2004; 10: 509–13 Perez et al, J Clin Oncol 2001; 19: 4216–23

36. Response Rates: MBC Re-exposure to Single-agent Taxanes
Valero et al, J Clin Oncol 1998; 16: 3362–8 Seidman et al, J Clin Oncol 1996; 14: 1877–84 Yonemori et al, Breast Cancer Res Treat 2005; 89: 237–41
Sawaki et al, Tumori 2004; 90: 36–9
Nishimura et al, Chemotherapy 2005; 51: 126–31 Taguchi et al, Breast J 2004; 10: 509–13 Perez et al, J Clin Oncol 2001; 19: 4216–23

37. Time to Progression: MBC Re-exposure to Single-agent Taxanes
Nishimura et al, Chemotherapy 2005; 51: 126–31 Taguchi et al, Breast J 2004; 10: 509–13 Perez et al, J Clin Oncol 2001; 19: 4216–23
Valero et al, J Clin Oncol 1998; 16: 3362–8 Seidman et al, J Clin Oncol 1996; 14: 1877–84 Yonemori et al, Breast Cancer Res Treat 2005; 89:
237–41Sawaki et al, Tumori 2004; 90: 36–9

38. Epothilones as Anticancer Agents
Epothilones are tubulin-binding agents
Ixabepilone is currently the only FDA-approved epothilone
in combination with capecitabine for the treatment of patients with metastatic or locally advanced breast cancer resistant to treatment with an anthracycline and a taxane
as monotherapy for the treatment of metastatic or locally advanced breast cancer in patients whose tumors are resistant or refractory to anthracyclines, taxanes, and capecitabine

39. Phase II Study of Ixabepilone in Taxane-refractory MBC
*5/6 responders had not responded to prior taxane therapy
Thomas et al, J Clin Oncol 2007; 25: 3399–406

40. Phase II Study of Ixabepilone in Taxane Pre-treated Locally Advanced or MBC
Low et al, J Clin Oncol 2005; 23: 2726–34

41. Ixabepilone Efficacy in Heavily Pre-treated MBC Study Design
Perez et al, J Clin Oncol 2007; 25: 3407–14

42. Ixabepilone in Heavily Pre-treated MBC Response
Perez et al, J Clin Oncol 2007; 25: 3407–14

43. Ixabepilone in Heavily Pre-treated MBC Survival
Perez et al, J Clin Oncol 2007; 25: 3407–14

44. Capecitabine ± Ixabepilone in Anthracycline- and Taxane-resistant, Locally Advanced or MBC Response
Thomas et al, J Clin Oncol 2007; 25: 5210–7

45. Capecitabine ± Ixabepilone in Anthracycline- and Taxane-resistant, Locally Advanced or MBC Grade 3/4 Adverse Events
*70/79 treated cases resolved after treatment discontinuation, median time to event resolution 6 weeks
Most common grade 3/4 events
Thomas et al, J Clin Oncol 2007; 25: 5210–7

46. Phase II Study of Ixabepilone in Taxane-naïve, Second-line MBC
Denduluri et al, J Clin Oncol 2007; 25: 3421–7

47. Ixabepilone as First-line Therapy in MBC Patients Following Adjuvant Anthracyclines Study Design
Roché et al, J Clin Oncol 2007; 25: 3415–20

48. Ixabepilone as First-line Therapy in MBC Patients Following Adjuvant Anthracyclines Efficacy
Roché et al, J Clin Oncol 2007; 25: 3415–20

49. Ixabepilone Studies in Taxane-naïve or Pre-treated MBC Response Rate
1Thomas et al, J Clin Oncol 2007; 25: 3399–406
Low et al, J Clin Oncol 2005; 23: 2726–34 Perez et al, J Clin Oncol 2007; 25: 3407–14
2Thomas et al, J Clin Oncol 2007; 25: 5210–7
3Roché et al, ASCO 2002; Abstract 223 Denduluri et al, J Clin Oncol 2007; 25: 3421–7 4Roché et al, J Clin Oncol 2007; 25: 3415–20 Moulder et al, SABCS 2007; Abstract 152

50. Ixabepilone Efficacy by Disease Stage and Degree of Resistance
A/T=anthracycline- / taxane-resistant, Multi=multi-resistant, T=taxane-resistant, T-naïve=taxane-naïve
Adapted from, Fumoleau et al, ECCO 2007; Abstract 2119

51. Case #2
47-year old female presents with recurrent metastatic BC involving the liver (3 lesions) and bone. Bx confirmed IDC – (ER, PR, HER2-negative)
2 years earlier the patient was diagnosed with Stage II IDC of the right breast (T = 3 cm; N = 3 of 12 positive axillary nodes); ER, PR, HER2-negative
Treatment included BCS followed by RT and dose-dense AC followed by T

52. Case #2 (cont.)
At this time what systemic treatment would you recommend?
Paclitaxel and bevacizumab
Capecitabine
Capecitabine and docetaxel
Gemcitabine and paclitaxel
nab-paclitaxel

53. Case #2 (cont.)
At this time what systemic treatment would you recommend?
Paclitaxel and bevacizumab
Capecitabine
Capecitabine and docetaxel
Gemcitabine and paclitaxel
nab-paclitaxel
Recommended Approach:
The use of Capecitabine as a single agent is a reasonable option.
Most patients tolerate the drug well.
It has become very useful as an oral medication

54. Case #2 (cont.) The patient receives capecitabine as a single agent
Repeat scans after 3 cycles confirm a partial response in the liver and stable bone lesions
Capecitabine is continued for 7 months at which time disease progression is documented in the liver
PS-1, LFT remain normal

55. Case #2 (cont.) At this time you would recommend:
Docetaxel and bevacizumab
Paclitaxel and bevacizumab
Ixabepilone
Gemcitabine
Navelbine

56. Case #2 (cont.) Recommended Approach:
Eliminate Gemcitabine and Navelbine as first choices.
Clinical data supports Docetaxel + Bevacizumab, Paclitaxel + Bevacizumab and Ixabepilone

57. Conclusions
The tolerability profiles of classic solvent-based taxanes are not optimal, warranting the advent of new tubulin inhibitor formulations
nab paclitaxel has demonstrated favorable efficacy versus solvent-based taxanes, while decreasing the severity of neutropenia and shortening the resolution of neuropathy
Many patients with progressive MBC, following prior treatment with anthracyclines and taxanes ( and capecitabine), remain good candidates for additional systemic therapy

58. Conclusions (cont.)
Identifying optimal treatment choices in this population is a challenge
Ixabepilone represents the first FDA-approved epothilone for treatment of advanced breast cancer
Ixabepilone has significant antitumor activity in heavily pretreated patients with a manageable toxicity profile
Ongoing clinical trials will establish the role of ixabepilone in chemo-naïve patients and in combination with biologic agents

59. Clinical Updates
Tubulin Inhibition in Breast Cancer: A Therapeutic Target Critical to Improving Outcomes