PBYI Surges 30% in 3 Months: How Should You Play the Stock?

Puma Biotechnology PBYI stock delivered a solid performance in the past three months, with its shares rallying 29.6% compared with the industry’s rise of 3.9%. The stock has also outperformed the sector and the S&P 500 index, as shown in the chart below.

The key driver of the stock’s increase was better-than-expected results announced last month. Additionally, sales of Nerlynx, its sole marketed product, are improving and positive momentum is building around its pipeline. Let us delve deeper and take a closer look at Puma Biotechnology and how we should approach things.

Improving Nerlynx Sales Aid PBYI

Nerlynx (neratinib) is approved for treating early-stage HER2-positive breast cancer in patients previously treated with Roche’s RHHBY Herceptin-based adjuvant therapy. Nerlynx is also approved in combination with Xeloda (capecitabine) for treating certain patients with advanced or metastatic HER2-positive breast cancer. The drug currently contributes the majority of PBYI’s revenues.

Nerlynx sales have been improving in the past couple of quarters. Sales of the drug rose 9% on a year-over-year basis to $92.3 million in the first six months of 2025. The company expects continued demand-driven growth in Nerlynx sales during the second half of 2025, which is likely to aid top-line growth.

Nerlynx product sales are expected to be in the range of $192-$198 million in 2025.

Alisertib - A Promising Pipeline Candidate for PBYI

Puma Biotechnology in-licensed the global development and commercialization rights to alisertib, an aurora kinase A inhibitor, from Japan’s Takeda in 2022. It is developing alisertib for hormone receptor-positive breast cancer as well as small-cell lung cancer (SCLC).

The company is conducting ALISCA-Lung1, a phase II study (PUMA-ALI-4201) evaluating alisertib as a monotherapy for the treatment of patients with extensive-stage SCLC. Interim data from this study are expected to be announced in the fourth quarter of 2025.

PBYI is also conducting a phase II ALISCA-Breast1 study on alisertib in combination with endocrine treatment for treating patients with chemotherapy-naïve HER2-negative, hormone receptor-positive metastatic breast cancer. Initial data from the study is also expected in the fourth quarter of 2025.

Per management, if successfully developed, alisertib has the potential to boost the company’s position in the anticancer drug market and lower its heavy dependence on Nerlynx for revenues.

PBYI's Overdependence on Nerlynx & Competition in the Target Market

Puma Biotechnology has no approved product in its portfolio other than Nerlynx. As a result, the company remains heavily dependent on Nerlynx for revenues and overall growth.

While the breast cancer market holds immense commercial potential, Nerlynx faces intense competition in the targeted space. Established therapies include RHHBY's Herceptin and Novartis' Tykerb.

A few other companies are also developing treatments for extensive-stage SCLC. These dynamics create substantial challenges for the company, as alisertib, even if successfully developed, would likely encounter intense competition in its target market.

PBYI's Valuation & Estimates

From a valuation standpoint, Puma Biotechnology is trading at a discount to the industry. Going by the price-to-sales (P/S) ratio, the company’s shares currently trade at 0.94, lower than 2.13 for the industry. The stock is trading above its five-year mean of 0.73.

The Zacks Consensus Estimate for 2025 earnings per share has moved up from 65 cents to 66 cents over the past 60 days. During the same time frame, earnings per share estimates for 2026 have increased from 51 cents to 60 cents.

Conclusion

Puma Biotechnology’s recent rally has been positive, given the improving sales performance of Nerlynx. The steady performance of Nerlynx, along with encouraging pipeline progress, should help the stock gain further momentum in 2025.

However, competition in the target remains a major concern. Any failure in ongoing studies and pipeline/regulatory setbacks will hurt growth prospects.

We advise a wait-and-watch stance for prospective investors as of now. Those who already own the stock can stay invested. Successful data readouts from its ongoing studies on alisertib will be an important catalyst for the stock.

Puma Biotechnology, Inc. Price

Puma Biotechnology, Inc. price | Puma Biotechnology, Inc. Quote

PBYI's Zacks Rank & Stocks to Consider

Puma Biotechnology currently carries a Zacks Rank #3 (Hold).

Some better-ranked stocks in the biotech sector are ANI Pharmaceuticals ANIP and CorMedix CRMD, each carrying a Zacks Rank #1 (Strong Buy) at present. You can see the complete list of today’s Zacks #1 Rank stocks here.

In the past 60 days, estimates for ANI Pharmaceuticals’ 2025 earnings per share have moved up from $6.53 to $7.25. Earnings per share estimates for 2026 have increased from $7.07 to $7.74 during the same period. ANIP stock has soared 76.7% year to date.

ANI Pharmaceuticals’ earnings beat estimates in each of the trailing four quarters, the average surprise being 22.66%.

In the past 60 days, estimates for CorMedix’s 2025 earnings per share have moved up from $1.10 to $1.52. Earnings per share estimates for 2026 have increased from $1.46 to $2.12 during the same period. CRMD stock has surged 59.7% year to date.

CorMedix’s earnings beat estimates in each of the trailing four quarters, the average surprise being 34.85%.

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This article originally published on Zacks Investment Research (zacks.com).

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