PUMA BIOTECHNOLOGY, INC.

Previous wording

We currently market NERLYNX in the United States using our direct specialty sales force consisting of approxima tely 40 sales specialists. Our sales specialists are supported by an experienced sales leadership team consisting of several regional business leaders and a Vice President of sales, as well as experienced professionals in marketing, managed markets, access and reimbursement, research, and sales planning and operations. Outside the United States, we seek to enter into exclusive sub-license agreements with third parties to pursue regulatory approval, if necessary, and commercialize NERLYNX, if approved. As of March 31 2025, NERLYNX has received approval for the treatment of certain patients with extended adjuvant and/or metastatic HER2-positive breast cancer in over 50 countries outside the United States. We are currently party to several sub-licenses in various regions outside the United States, including Europe (excluding Russia and Ukraine), Australia, Canada, China, Southeast Asia, Israel, South Korea, and various countries and territories in Central America, South America, Africa and the Middle East.

Current wording

We currently market NERLYNX in the United States using our direct specialty sales force consisting of approxima tely 38 sales specialists. Our sales specialists are supported by an experienced sales leadership team consisting of several regional business leaders and a Vice President of sales, as well as experienced professionals in marketing, managed markets, access and reimbursement, research, and sales planning and operations. Outside the United States, we seek to enter into exclusive sub-license agreements with third parties to pursue regulatory approval, if necessary, and commercialize NERLYNX, if approved. As of June 30, 2025, NERLYNX has received approval for the treatment of certain patients with extended adjuvant or metastatic HER2-positive breast cancer in over 40 countries outside the United States. We are currently party to several sub-licenses in various regions outside the United States, including Europe, Australia, Canada, China, Southeast Asia, Israel, South Korea, Russia and various countries and territories in Central America, South America, Africa and the Middle East.

Previous wording

As of the date of the filing of this Quarterly Report, we believe there have been no material changes to our critical accounting policies and estimates during the three months ended March 31, 2025 from our accounting policies at December 31, 2024, as reported in our Annual Report on Form 10-K for the fiscal year ended December 31, 2024.

Current wording

As of the date of the filing of this Quarterly Report, we believe there have been no material changes to our critical accounting policies and estimates during the six months ended June 30, 2025 from our accounting policies at December 31, 2024, as reported in our Annual Report on Form 10-K for the fiscal year ended December 31, 2024.

Previous wording

Research and development expenses (“R&D expenses”) include costs associated with services provided by consultants who conduct and perform clinical services on our behalf and contract organizations for the manufacturing of clinical materials. During the three months ended March 31, 2025 and 2024, our R&D expenses consisted primarily of clinical research organization (“CRO fees”); fees paid to consultants; salaries and related personnel costs; and stock-based compensation. We expense our R&D expenses as they are incurred. Internal R&D expenses primarily consist of payroll-related costs and also include equipment costs, travel expenses and supplies.

Current wording

Research and development expenses (“R&D expenses”) include costs associated with services provided by consultants who conduct and perform clinical services on our behalf and contract organizations for the manufacturing of clinical materials. During the three and six months ended June 30, 2025 and 2024, our R&D expenses consisted primarily of clinical research organization (“CRO fees”); fees paid to consultants; salaries and related personnel costs; and stock-based compensation. We expense our R&D expenses as they are incurred. Internal R&D expenses primarily consist of payroll-related costs and also include equipment costs, travel expenses and supplies.

Previous wording

Total revenue for the three months ended March 31, 2025 was approximately $46.0 million, compared to $43.8 million for the three months ended March 31, 2024. This increase in total revenue was primarily due to an increase in product revenue, net of approximately $2.8 million, partially offset by a decrease in royalty revenue of $0.6 million.

Current wording

Total revenue for the three months ended June 30, 2025 was approximately $52.4 million, compared to $47.1 million for the three months ended June 30, 2024. This increase in total revenue was due to an increase in product revenue, net of approximately $4.8 million and an increase in royalty revenue of $0.6 million.

Previous wording

Product revenue, net was approximately $43.1 million for the three months ended March 31, 2025, compared to $40.3 million for the three months ended March 31, 2024. This increase in product revenue, net, compared to the three months ended March 31, 2024, was primarily attributable to an increase in net selling price, partially offset by a decrease of approximately 3.0%in bottles of NERLYNX sold in the U.S. market, and a decrease of approximately 2.6% in related deductions to gross revenue for variable consideration.

Current wording

Product revenue, net was approximately $49.2 million for the three months ended June 30, 2025, compared to $44.4 million for the three months ended June 30, 2024. This increase in product revenue, net, compared to the three months ended June 30, 2024, was attributable to a 4% increase inbottles of NERLYNX sold in the U.S. market and an increase in net selling price, partially offset by a slight increase in deductions to gross revenue for variable consideration, primarily related to government chargebacks.

Previous wording

Royalty revenue was approximately $2.9 million for the three months ended March 31, 2025, compared to approximately $3.5 million for the three months ended March 31, 2024. The decrease was primarily due to fewer international sales made by our sub-licensees.

Current wording

Royalty revenue was approximately $3.2 million for the three months ended June 30, 2025, compared to approximately $2.7 million for the three months ended June 30, 2024. The increase was primarily due to increased international sales made by our sub-licensees.

Previous wording

Cost of sales was approximately $10.6 million for the three months ended March 31, 2025, compared to approximately $10.7 million for the three months ended March 31, 2024. The slight decrease was primarily due to the change in our annual standard cost adjustment (higher raw material costs), partially offset by higher cost of sales to sub-licensees and royalty expense.

Current wording

Cost of sales was approximately $12.3 million for the three months ended June 30, 2025, compared to approximately $10.7 million for the three months ended June 30, 2024. The increase was primarily due to higher royalty expense and product costs resulting from increased worldwide net sales.

Previous wording

SG&A expenses were approximately $17.6 million for the three months ended March 31, 2025, compared to approximately $21.8 million for the three months ended March 31, 2024. SG&A expenses for the three months ended March 31, 2025 and 2024 were as follows:

Current wording

SG&A expenses were approximately $18.0 million for the three months ended June 30, 2025, compared to approximately $25.0 million for the three months ended June 30, 2024. SG&A expenses for the three months ended June 30, 2025 and 2024 were as follows:

Previous wording

SG&A expenses decreased by approximately$4.2 million for the three months ended March 31, 2025, compared to the same period in 2024, primarily attributable to the following:

Current wording

SG&A expenses decreased by approximately$6.9 million for the three months ended June 30, 2025, compared to the same period in 2024, primarily attributable to the following:

Previous wording

R&D expenses were approxi mately$13.9 million for thethree months ended March 31, 2025, compared to approximately $13.6 million for the three months ended March 31, 2024. R&D expenses for the three months ended March 31, 2025 and 2024, were as follows:

Current wording

R&D expenses were approxi mately$15.5 million for thethree months ended June 30, 2025, compared to approximately $13.6 million for the three months ended June 30, 2024. R&D expenses for the three months ended June 30, 2025 and 2024, were as follows:

Previous wording

R&D expenses increased by approxim ately$0.3 million for the three months ended March 31, 2025, compared to the same period in 2024, primarily attributable to the following:

Current wording

R&D expenses increased by approxim ately$1.8 million for the three months ended June 30, 2025, compared to the same period in 2024, primarily attributable to the following:

Previous wording

For the three months ended March 31, 2025, we recognized approximately $1.1 million in interest income, compared to approximately $1.0 million of interest income for the three months ended March 31, 2024. The increase in interest income was primarilythe result of improved investment management.

Current wording

For the three months ended June 30, 2025, we recognized approximately $1.0 million in interest income, compared to approximately $1.2 million of interest income for the three months ended June 30, 2024. The decrease in interest income was primarilythe result of lower investment balances and timing of investments.

Previous wording

For the three months ended March 31, 2025, we recognized approximately $2.2 million in interest expense, compared to approximately $3.4 million of interest expense for the three months ended March 31, 2024. The decrease in interest expense was primarily related to a lower debt balance as we began paying down our debt principal during the three months ended June 30, 2024.

Current wording

For the three months ended June 30, 2025, we recognized approximately $1.8 million in interest expense, compared to approximately $3.4 million of interest expense for the three months ended June 30, 2024. The decrease in interest expense was primarily related to a lower debt balance as we began paying down our debt principal during the three months ended June 30, 2024.

Previous wording

For the three months ended March 31, 2025, we recognized approximately $0.4 million in other income, compared to approximately $0.1 million of other income for the three months ended March 31, 2024. The increase inother income was primarily dueto favorable exchange rates in Euro-denominated transactions.

Current wording

For the three months ended June 30, 2025, we recognized approximately $0.4 million in other income, compared to approximately $0.2 million of other income for the three months ended June 30, 2024. The increase inother income was primarily dueto favorable exchange rates in Euro-denominated transactions.

Previous wording

The following table, which summarizes our liquidity and capital resources as of March 31, 2025 and December 31, 2024 and for the three months ended March 31, 2025 and 2024, is intended to supplement the more detailed discussion that follows:

Current wording

The following table, which summarizes our liquidity and capital resources as of June 30, 2025 and December 31, 2024 and for the six months ended June 30, 2025 and 2024, is intended to supplement the more detailed discussion that follows:

Previous wording

Cash provided by operating activities for thethree months ended March 31, 2025 was$3.6 million and consisted of net income of approximately$3.0 million, adjusted for non-cash items of approximately $5.0 million, which included stock-based compensation of $2.0 million, depreciation and amortization of $2.8 million and provision for credit loss of $0.2 million. Total changes in cash flows from operations were due to an increase in working capital, primarily related to a decrease in accrued expenses and other of approximately $9.9 million, a decrease in operating lease assets and liabilities, net, of $0.4 million and a decrease of post-marketing commitment liability of $0.4 million and an increase in prepaid and other expenses of $0.8 million, partially offset by a decrease in accounts receivable of approximately $6.6 million and an increase in accounts payable of $0.5 million.

Current wording

Cash provided by operating activities for thesix months ended June 30, 2025 was$17.7 million and consisted of net income of approximately$8.8 million, adjusted for non-cash items of approximately $9.1 million, which included stock-based compensation of $3.7 million, depreciation and amortization of $5.6 million and provision for credit loss recovery of $0.1 million. Total changes in cash flows from operations were due to a slight decrease in working capital, primarily related to a decrease in accrued expenses and other of approximately $5.0 million, a decrease in operating lease assets and liabilities, net, of $0.9 million and a decrease of post-marketing commitment liability of $1.1 million, partially offset by a decrease in prepaid and other expenses of $0.5 million, a decrease in accounts receivable of approximately $6.3 million and a decrease in inventory of $0.1 million.

Previous wording

Cash provided by operating activities for the three months ended March 31, 2024 was $11.2 million and consisted of a net loss of approximately $4.8 million, adjusted for non-cash items of approximately $5.4 million, including stock-based compensation of $2.4 million, depreciation and amortization of $2.9 million and provision for credit loss of $0.1 million. Total changes in cash flows from operations were due to an increase in working capital, primarily related to a decrease in accounts receivable, net of approximately $23.1 million and an increase in accounts payable of approximately $2.1 million, partially offset by a decrease in accrued expenses and other of approximately $15.0 million.

Current wording

Cash provided by operating activities for the six months ended June 30, 2024 was $12.3 million and consisted of a net loss of approximately $9.3 million, adjusted for non-cash items of approximately $10.2 million, including stock-based compensation of $4.4 million, depreciation and amortization of $5.8 million and provision for credit loss recovery of $0.1 million. Total changes in cash flows from operations were due to an increase in working capital, primarily related to a decrease in accounts receivable of approximately $19.8 million, a decrease in prepaid expenses and other of $1.4 million and an increase in accounts payable of approximately $6.6 million, partially offset by a decrease in accrued expenses and other of approximately $13.7 million and an increase in inventory of approximately $2.0 million.

Previous wording

Cash provided by investing activities for thethree months ended March 31, 2025 was approximately$1.5 million, compared to net cash used in investing activities of approximately$19.1 million for the same period in 2024. Cash provided by investing activities for the three months ended March 31, 2025 was primarily due to maturity of available-for-sale securities of approximately $14.1 million, partially offset by the purchase of available-for-sale securities of approximately $12.5 million.

Current wording

Cash used in investing activities for thesix months ended June 30, 2025 was approximately$9.7 million, compared to net cash used in investing activities of approximately$18.4 million for the same period in 2024. Cash used in investing activities for the six months ended June 30, 2025 was primarily due to the purchase of available-for-sale securities of approximately $34.4 million, partially offset by the maturity of available-for-sale securities of approximately $24.8 million.

Previous wording

Cash used in investing activities for the three months ended March 31, 2024 was approximately $19.1 million. Cash used in investing activities for the three months ended March 31, 2024 was primarily due to the purchase of available-for-sale securities of approximately $25.0 million, offset by the maturity of available-for-sale securities of approximately $5.9 million.

Current wording

Cash used in investing activities for the six months ended June 30, 2024 was approximately $18.4 million, compared to net cash used by investing activities of approximately $22.1 million for the same period in 2023. Cash used in investing activities was primarily due to the purchase of available-for-sale securities of approximately $44.9 million, offset by the maturity of available-for-sale securities of approximately $26.5 million.

Previous wording

As of March 31, 2025, the principal balance outstanding under the Athyrium Notes was $55.6 million and represents all of our debt. We are in compliance with all applicable covenants under the Athyrium Notes.

Current wording

As of June 30, 2025, the principal balance outstanding under the Athyrium Notes was$44.5 million and represents all of our debt. We are in compliance with all applicable covenants under the Athyrium Notes.

Previous wording

We did not receive or record any product revenue until the third quarter of 2017. We have spent, and expect to continue to spend, substantial amounts in connection with implementing our business strategy, including our planned product development efforts, our clinical trials, our R&D efforts and our commercialization efforts.

Current wording

We have spent, and expect to continue to spend, substantial amounts in connection with implementing our business strategy, including our planned product development efforts, our clinical trials, our R&D efforts and our commercialization efforts.

Previous wording

We may choose to begin new R&D efforts, or we may choose to launch additional marketing efforts. For example, we in-licensed alisertib from Takeda in 2022 and assumed sole responsibility for its global development and commercialization. These efforts will require funding in addition to the cash and cash equivalents totaling approximately $63.0 million and approximately $30.1 million in marketable securities available at March 31, 2025. While our consolidated financial statements have been prepared on a going concern basis, we may incur significant losses in the future and will need to generate significant revenue to sustain operations and successfully commercialize neratinib and develop alisertib. While we have been successful in raising financing in the past, there can be no assurance that we will be able to do so in the future. Our ability to obtain funding may be adversely impacted by uncertain market conditions, our success in commercializing neratinib, our success in developing alisertib, unfavorable decisions of regulatory authorities or adverse clinical trial results. The outcome of these matters cannot be predicted at this time. We believe that our existing cash and cash equivalents and marketable securities as of March 31, 2025, and proceeds that will become available to us through product sales and sub-license payments are sufficient to satisfy our operating cash and capital needs for at least one year after the filing of this Quarterly Report.

Current wording

We may choose to begin new R&D efforts, or we may choose to launch additional marketing efforts. For example, we in-licensed alisertib from Takeda in 2022 and assumed sole responsibility for its global development and commercialization. These efforts will require funding in addition to the cash and cash equivalents totaling approximately$54.7 million and approximately$41.4 million in marketable securities available at June 30, 2025. While our consolidated financial statements have been prepared on a going concern basis, we may incur significant losses in the future and will need to generate significant revenue to sustain operations and successfully commercialize neratinib and develop alisertib. While we have been successful in raising financing in the past, there can be no assurance that we will be able to do so in the future. Our ability to obtain funding may be adversely impacted by uncertain market conditions, our success in commercializing neratinib, our success in developing alisertib, unfavorable decisions of regulatory authorities or adverse clinical trial results. The outcome of these matters cannot be predicted at this time. We believe that our existing cash and cash equivalents and marketable securities as of June 30, 2025, and proceeds that will become available to us through product sales and sub-license payments are sufficient to satisfy our operating cash and capital needs for at least one year after the filing of this Quarterly Report.

Previous wording

In addition to our operating results, as calculated in accordance with Generally Accepted Accounting Principles (“GAAP”) we use certain non-GAAP financial measures when planning, monitoring, and evaluating our operational performance. The following table presents our net income (loss) and net income (loss) per share, as calculated in accordance with GAAP, as adjusted to remove the impact of stock-based compensation. For the three months ended March 31, 2025, stock-based compensation represented approximately 6.4% of our operating expenses, compared to 6.7% for the same period in 2024, in each case excluding cost of sales. Our management believes that these non-GAAP financial measures are useful to enhance understanding of our financial performance, are more indicative of our operational performance and facilitate a better comparison among fiscal periods. These non-GAAP financial measures are not, and should not be viewed as, substitutes for GAAP reporting measures.

Current wording

In addition to our operating results, as calculated in accordance with Generally Accepted Accounting Principles (“GAAP”) we use certain non-GAAP financial measures when planning, monitoring, and evaluating our operational performance. The following table presents our net income (loss) and net income (loss) per share, as calculated in accordance with GAAP, as adjusted to remove the impact of stock-based compensation. For thethree and six months ended June 30, 2025, stock-based compensation represented approximately 4.9% and 5.6% of our operating expenses, respectively, compared to 5.3% and 6.0% for the same respective periods in 2024, in each case excluding cost of sales. Our management believes that these non-GAAP financial measures are useful to enhance understanding of our financial performance, are more indicative of our operational performance and facilitate a better comparison among fiscal periods. These non-GAAP financial measures are not, and should not be viewed as, substitutes for GAAP reporting measures.

Previous wording

(3) Non-GAAP adjusted basic net income (loss) per share was calculated based on 49,595,697 and 48,189,256 weighted-average shares of common stock outstanding for the three months ended March 31, 2025 and 2024, respectively.

Current wording

(3) Non-GAAP adjusted basic net income per share was calculated based on 49,700,217 and 49,648,246 weighted-average shares of common stock outstanding for the three and six months ended June 30, 2025, respectively.

Previous wording

(4) Non-GAAP adjusted diluted net income per share was calculated based on 49,906,341 weighted-average shares of common stock outstanding for the three months ended March 31, 2025.

Current wording

(5) Non-GAAP adjusted diluted net income per share was calculated based on 50,144,704 and 50,003,709 weighted-average shares of common stock outstanding for the three and six months ended June 30, 2025, respectively.

Previous wording

(5) Potentially dilutive common stock equivalents were not included in this non-GAAP adjusted diluted net loss per share for the three months ended March 31, 2024, as these shares would be considered anti-dilutive.

Current wording

(6) Potentially dilutive common stock equivalents (stock options restricted stock units and warrants) were not included in this non-GAAP adjusted diluted net loss per share for the three and six months ended June 30, 2024, as these shares would be considered anti-dilutive.