ATRA Stock: Insider Activity, Filings & Research
Atara Biotherapeutics, Inc. (ATRA) — Drillr’s hub for ATRA insider activity, SEC filings, earnings signals and AI research. Over the trailing 3 months, ATRA insiders filed 1 open-market buy and 3 sales (SEC Form 4).
ATRA insider trading activity (SEC Form 4)
| Date | Insider | Type | Shares | Price |
|---|---|---|---|---|
| May 20, 2026 | Nguyen AnhCodirector, officer: President and CEO | Sell | 5,241 | $9.13 |
| May 20, 2026 | Grant-Huerta Yaninaofficer: Chief Accounting Officer | Sell | 2,414 | $9.13 |
| May 11, 2026 | EcoR1 Capital, LLC10 percent owner | Buy | 507,407 | $9.35 |
| May 11, 2026 | Panacea Innovation Ltd10 percent owner | Sell | 313,446 | $10.10 |
| Mar 19, 2026 | Panacea Innovation Ltd10 percent owner | Option | 259,163 | $0.00 |
| Mar 19, 2026 | Panacea Innovation Ltd10 percent owner | Tax | 5 | $5.23 |
| Mar 11, 2026 | Grant-Huerta Yaninaofficer: Chief Accounting Officer | Grant | 20,300 | — |
| Mar 11, 2026 | Nguyen AnhCodirector, officer: President and CEO | Grant | 81,100 | — |
| Mar 4, 2026 | Nguyen AnhCodirector, officer: President and CEO | Sell | 58 | $5.08 |
| Mar 4, 2026 | Grant-Huerta Yaninaofficer: Chief Accounting Officer | Sell | 1,603 | $5.08 |
| Mar 4, 2026 | Grant-Huerta Yaninaofficer: Chief Accounting Officer | Sell | 377 | $5.08 |
| Mar 4, 2026 | Nguyen AnhCodirector, officer: President and CEO | Sell | 198 | $5.08 |
| Mar 4, 2026 | Nguyen AnhCodirector, officer: President and CEO | Sell | 1,298 | $5.09 |
| Mar 4, 2026 | Grant-Huerta Yaninaofficer: Chief Accounting Officer | Sell | 24 | $5.08 |
| Mar 4, 2026 | Grant-Huerta Yaninaofficer: Chief Accounting Officer | Sell | 100 | $5.08 |
Source: ATRA SEC Form 4 filings, latest May 20, 2026. For informational purposes only — not investment advice.
Atara Biotherapeutics, Inc. company profile
Overview
Atara Biotherapeutics, Inc. (NASDAQ:ATRA) is a clinical-stage biotechnology company founded in 2012 and headquartered in South San Francisco, California. The company went public in October 2014 and specializes in developing off-the-shelf T-cell immunotherapies for patients with cancer, autoimmune diseases, and viral infections. Atara has evolved from a broad-based immunotherapy developer to a more focused organization following strategic partnerships and operational restructuring in recent years.
Business
Atara Biotherapeutics operates in the biotechnology sector, specifically focusing on T-cell immunotherapy development. T-cell immunotherapy is a form of cancer treatment that harnesses the body's immune system by using specially engineered T-cells (a type of white blood cell) to target and destroy cancer cells or treat other diseases. The company's approach centers on off-the-shelf or allogeneic T-cell therapies, which means these treatments are manufactured from donor cells and can be used across multiple patients without requiring personalized cell extraction from each individual patient. This contrasts with autologous therapies that require harvesting a patient's own cells, making the treatment process longer and more expensive. Atara's primary business segments include: 1. Tabelecleucel (tab-cel) - The company's lead product candidate, currently in Phase 3 clinical trials for treating Epstein-Barr virus (EBV) driven post-transplant lymphoproliferative disease (PTLD). This condition occurs when patients who have received organ transplants develop lymphomas due to EBV infections, taking advantage of their suppressed immune systems. Tab-cel is also being investigated for other EBV-positive cancers including nasopharyngeal carcinoma. 2. CAR-T Cell Therapies - Atara develops next-generation Chimeric Antigen Receptor T-cell (CAR-T) therapies including ATA2271 and ATA3271 targeting mesothelin for solid tumors, and ATA2431 and ATA3219 for B-cell malignancies. CAR-T therapy involves genetically modifying T-cells to better recognize and attack specific cancer cells. 3. Autoimmune Applications - The company is developing ATA188 for treating multiple sclerosis, representing an expansion of T-cell therapy beyond cancer into autoimmune diseases. 4. Viral Disease Programs - Including ATA368 for human papillomavirus (HPV) associated cancers. The company generates revenue primarily through licensing agreements and collaboration partnerships, with tab-cel representing the most advanced program closest to potential commercialization.
Revenue model
Atara Biotherapeutics operates on a licensing and partnership-based revenue model typical of clinical-stage biotechnology companies. The company generates income through upfront payments, milestone payments, and royalty agreements from pharmaceutical partners who help develop and commercialize its therapies. The company's primary revenue streams include: 1. Licensing Revenue - Atara has secured significant partnerships, most notably with Pierre Fabre for tab-cel, which provides up to $640 million in total consideration including approximately $30 million upfront, up to $100 million in regulatory milestones, and double-digit tiered royalties on future sales. 2. Collaboration Revenue - The company has various research and development partnerships with institutions like Memorial Sloan Kettering Cancer Center and QIMR Berghofer Medical Research Institute, which provide funding for specific research programs. 3. Milestone Payments - As clinical programs advance through development phases, partners pay predetermined milestone amounts upon achieving specific regulatory or clinical objectives. The company's paying customers are primarily large pharmaceutical companies and research institutions rather than end patients, as Atara's products are still in clinical development. Several factors significantly impact Atara's financial performance and margins. Positive factors include successful clinical trial results that trigger milestone payments, regulatory approvals that enable royalty streams, and strategic partnerships that provide upfront capital and reduce development costs. The company's off-the-shelf approach potentially offers better margins than personalized therapies due to manufacturing efficiencies. Negative factors include high clinical development costs, regulatory delays or failures that can eliminate revenue streams, competitive pressure from other immunotherapy developers, and the inherent risks of biotechnology development where most programs fail to reach commercialization. Manufacturing costs for complex cell therapies remain high, and reimbursement challenges from healthcare systems can limit commercial potential even for approved products.
Competitive moat
Atara Biotherapeutics operates in a competitive biotechnology landscape with limited sustainable competitive advantages. The company's primary moat lies in its off-the-shelf T-cell platform technology and accumulated clinical data, particularly for tab-cel which has advanced to Phase 3 trials. This represents years of clinical development investment and regulatory knowledge that competitors would need to replicate. The company benefits from intellectual property protection around its specific T-cell engineering approaches and manufacturing processes. Additionally, Atara has established relationships with key research institutions and regulatory bodies, providing some operational advantages in clinical development. However, the company's moat is relatively narrow and vulnerable to several competitive threats. Large pharmaceutical companies with significantly more resources are actively developing competing T-cell therapies, including both allogeneic and autologous approaches. Companies like Bristol Myers Squibb, Novartis, and Gilead Sciences have already commercialized CAR-T therapies and continue investing heavily in next-generation platforms. The biotechnology sector is characterized by rapid technological advancement, meaning Atara's current approaches could become obsolete if competitors develop superior manufacturing methods, more effective targeting mechanisms, or overcome current limitations like manufacturing complexity and cost. The company also faces potential disruption from entirely different therapeutic approaches, such as other forms of immunotherapy, targeted therapies, or emerging modalities like gene editing. Atara's dependence on partnerships for commercialization further limits its competitive control, as partners may prioritize other products in their portfolios or terminate agreements if clinical results disappoint. The company's relatively small size compared to major pharmaceutical companies also constrains its ability to compete in multiple therapeutic areas simultaneously or weather significant clinical setbacks.
Risks & safety
Atara Biotherapeutics presents significant financial risk with limited margin of safety for investors. • Cash Position and Burn: The company had $13.8 million in cash and short-term investments as of Q1 2025, down from $25.0 million in Q4 2024. With quarterly operating cash flow losses of $28.1 million in Q1 2025, the company faces immediate liquidity concerns and likely needs additional financing within months. • Debt and Solvency: Total liabilities of $117.1 million significantly exceed total assets of $62.0 million, creating negative shareholder equity of approximately $55 million. Current liabilities of $47.9 million exceed current assets of $27.2 million, indicating potential near-term solvency issues. • Valuation Metrics: The stock trades at extremely low multiples due to financial distress - P/E ratio of 0.42 (based on unusual positive Q1 2025 earnings), EV/EBITDA of 0.47, and negative book value. These metrics reflect the company's precarious financial position rather than attractive valuation. • Other Considerations: The company has been burning cash consistently, with free cash flow losses of $69.0 million in 2024. Revenue volatility is high due to lumpy partnership payments, and the company faces significant dilution risk from potential equity raises needed to fund operations.
Recent development
Atara Biotherapeutics has undergone significant strategic transformation over the past few years, shifting from a broad-based immunotherapy developer to a more focused organization through partnerships and operational restructuring. The most significant development was the expanded global partnership with Pierre Fabre in 2023 for tab-cel, providing up to $640 million in total consideration including $30 million upfront and up to $100 million in regulatory milestones. This partnership allows Pierre Fabre to handle global commercialization while reimbursing Atara for development costs, fundamentally changing the company's financial model and reducing capital requirements. In response to financial pressures, Atara implemented substantial cost reduction measures including a 30% workforce reduction and operational streamlining designed to reduce annual cash expenditures by 40% or approximately $100 million by the end of 2025. These measures were intended to extend the company's cash runway and focus resources on core programs. The company has narrowed its pipeline focus to key programs, terminating the Bayer collaboration for mesothelin CAR-T programs and pausing certain development activities. Priority programs now center on tab-cel for EBV-positive diseases, ATA188 for multiple sclerosis, and select CAR-T programs like ATA3219 for B-cell malignancies. Clinical progress has been mixed, with tab-cel advancing toward potential regulatory filings and ATA188 completing its EMBOLD study for progressive multiple sclerosis with results expected to guide future development decisions. The company has been working with regulatory agencies, particularly the FDA, to establish pathways for product approvals that minimize additional clinical trial requirements. Recent financial results show revenue volatility due to the partnership-dependent model, with significant fluctuations between quarters based on milestone achievements and collaboration payments. The company continues seeking additional partnerships to reduce development risks and capital requirements while maintaining meaningful upside participation in successful programs.
ATRA company profile · for informational purposes only — not investment advice.
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