8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): December 21, 2015

PUMA BIOTECHNOLOGY, INC.

(Exact Name of Registrant as Specified in its Charter)

Delaware	001-35703	77-0683487
(State or other jurisdiction of incorporation)	(Commission File Number)	(IRS Employer Identification No.)

10880 Wilshire Boulevard, Suite 2150

Los Angeles, California 90024

(Address of principal executive offices) (Zip Code)

(424) 248-6500

(Registrant’s telephone number, including area code)

N/A

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 8.01 Other Events.

On December 21, 2015, Puma Biotechnology, Inc. (the “Company”) hosted a conference call and slide presentation to discuss preliminary results of its Phase II study looking at the incidence and severity of diarrhea in patients with early-stage HER2-positive breast cancer treated with extended adjuvant neratinib monotherapy and prophylactic loperamide. A copy of the slide presentation is filed herewith as Exhibit 99.1 and is incorporated by reference herein.

Forward-Looking Statements:

The slide presentation contains forward-looking statements, including statements regarding the anticipated timing for a clinical trial and the announcement of data relative to this trial. All forward-looking statements included in the slide presentation involve risks and uncertainties that could cause the Company’s actual results to differ materially from the anticipated results and expectations expressed in these forward-looking statements. These statements are based on current expectations, forecasts and assumptions, and actual outcomes and results could differ materially from these statements due to a number of factors, which include, but are not limited to, the fact that the Company has no product revenue and no products approved for marketing, the Company’s dependence on PB272, which is still under development and may never receive regulatory approval, the challenges associated with conducting and enrolling clinical trials, the risk that the results of clinical trials may not support the Company’s drug candidate claims, even if approved, the risk that physicians and patients may not accept or use the Company’s products, the Company’s reliance on third parties to conduct its clinical trials and to formulate and manufacture its drug candidates, the Company’s dependence on licensed intellectual property, and the other risk factors disclosed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014 and in subsequent periodic and current reports filed by the Company with the Securities and Exchange Commission from time to time. Readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of the slide presentation, December 21, 2015. The Company assumes no obligation to update these forward-looking statements, except as required by law.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

99.1 Slide Presentation

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	PUMA BIOTECHNOLOGY, INC.
Date: December 23, 2015	By:	/s/ Alan H. Auerbach
		Alan H. Auerbach
		President and Chief Executive Officer

EXHIBIT INDEX

Exhibit No.	Description
99.1	Slide Presentation

EX-99.1

Exhibit 99.1

An Open-Label Study to Characterize the Incidence and Severity of Diarrhea in Patients with Early-Stage HER2+ Breast Cancer Treated with Neratinib and Intensive Loperamide Prophylaxis

Copyright 2015 Puma Biotechnology

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Diarrhea in ExteNET Trial

1.0 Diarrhea grade

1

2

0.8 3

4

0.6

Incidence 0.4

0.2

0.0

1 2 3 4 5 6 7 8 9 10 11 12

Study time (months)

Pts with events 1310 692 615 569 513 490 453 413 437 414 392 366

Pts at risk 1408 1146 1074 1033 1006 971 935 924 911 888 873 863

Diarrhea*

95.4% All Grade (Grade 1-4) diarrhea

39.9% Grade 3 (or higher) diarrhea

Median duration of Grade 3 diarrhea: 5 days

1.4% of patients hospitalized due to diarrhea

26.4% of patients requiring dose reduction

16.8% of patients discontinuing neratinib due

to diarrhea

No prophylaxis with loperamide given in

ExteNET to prevent neratinib-related diarrhea

Neratinib-Diarrhea Prophylaxis with Loperamide in Metastatic Cancer

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Phase II Open-Label Study to Characterize the Incidence and Severity of Diarrhea in Patients with Early-Stage HER2+ Breast Cancer Treated with Neratinib and Intensive Loperamide Prophylaxis

Goal: Investigate the use of loperamide given prophylactically to reduce neratinib related diarrhea in patients treated for extended adjuvant HER2 positive breast cancer

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Study Schema and Status

Patients enter study within 1 year of completing adjuvant trastuzumab therapy (analogous to ExteNET population) Other prior HER2+ (neo) adjuvant therapy is permitted

Early HER2+ Breast Cancer

Received up to 1 year of adjuvant trastuzumab

Stage I-3c

HR (ER/PR) positive or negative

One year of therapy

Neratinib 240 mg

Loperamide

daily

Two cycles

FPI FEB 2015

Enrollment: 72 patients as of December 2015

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Dosing Regimens

Original Protocol (n=27)

Day 1 : 16 mg/day (4 mg starting dose + 4 mg tid) Days 2-3: 12 mg/day (4 mg tid) Days 4-56 : 6-8mg/day (2 mg tid or qid)

Amended Protocol (n=23)

Days 1-14: 12 mg/day (4 mg tid) Day 15-56: 8 mg/day (4 mg bid)

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Study Preliminary Results

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Patient Characteristics

Original Protocol Amendment 1 Total

(N=27)(N=23)(N=50)

Hormone receptor

23 (85.2%) 13 (56.5%) 36 (72%)

positive (ER/PR+)

Hormone receptor

4 (14.8%) 10 (43.5%) 14 (28%)

negative (ER/PR-)

Copyright 2015 Puma Biotechnology

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Incidence of Grade 3 Treatment-emergent Diarrhea

Original Protocol Amendment 1 Total

(N=27)(N=23)(N=50)

Patients with events—n (%)

Grade 3 Diarrhea 5 (18.5) 3 (13.0) 8 (16.0)

Incidence of Grade 3

18.5% (6.3, 38.1) 13.0% (2.8, 33.6) 16.0% (7.2, 29.1)

Diarrhea (95% CI)

Non Compliant

with Loperamide 3/5 (60%) 2/3 (67%) 5/8 (63%)

Prophylaxis

No patients developed grade 4 diarrhea

Copyright 2015 Puma Biotechnology

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Characteristics of Treatment-emergent Diarrhea

Original Protocol Amendment 1 Total

(N=27)(N=23)(N=50)

Any Grade – n (%) 20 (74.1) 10 (43.5) 30 (60.0)

Grade 3 5 (18.5) 3 (13.0) 8 (16.0)

Hospitalizations 0 (0.0) 0 (0.0) 0 (0.0)

Action taken – n (%)

Anti-diarrheal

9 (33.3) 6 (26.1) 15 (30.0)

medication

Temporarily stopped

0 (0.0) 1 (4.3) 1 (2.0)

neratinib

Reduced neratinib

2 (7.4) 1 (4.3) 3 (6.0)

dose

Discontinued neratinib

7 (25.9) 1 (4.3) 8 (16.0)

permanently

Copyright 2015 Puma Biotechnology

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Copyright 2015 Puma Biotechnology

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Treatment-emergent Diarrhea by Treatment Cycle

W = week C = cycle

Copyright 2015 Puma Biotechnology

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Duration of Treatment-emergent Diarrhea

Original Protocol Amendment 1 Total

(N=27)(N=23)(N=50)

Duration of any grade (grade 1-3) diarrhea (days)

Median 3.0 3.0 3.0

Duration of grade 3 diarrhea (days)

Median 1.0 2.0 2.0

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Summary of Findings

Based on preliminary results in patients receiving loperamide prophylaxis, the estimated frequency of all grade diarrhea is 60% and grade 3 diarrhea is 16%

- Estimated frequency of all grade diarrhea for original protocol is 74.1% and grade 3 diarrhea is 18.5%

- Estimated frequency of all grade diarrhea for Amendment 1 is 43.5% and grade 3 diarrhea is 13.0%

- For comparison, in ExteNET (where no loperamide prophylaxis was given) all grade diarrhea was 95.4% and grade 3 diarrhea 39.8%

Grade 3 diarrhea appears limited to first 28 days (cycle 1) with the majority occurring the first week

All grade and grade 3 diarrhea when using loperamide prophylaxis appears to be short-term and not chronic. There were no hospital admissions requiring IV fluids suggesting that the neratinib related diarrhea is acute, manageable and self-limiting

Copyright 2015 Puma Biotechnology

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Future Plans

Continue following additional patients in Amendment 1 cohort

Report additional results (n=72) in 2016

Copyright 2015 Puma Biotechnology

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