For many years, retail investors and biotech enthusiasts closely watched ctic stock, the ticker symbol for Seattle-based CTI BioPharma Corp. If you search for the CTIC ticker symbol on modern stock trackers today, you will find a flatlined chart, a delisting notice, or a blank page.
CTIC stock officially ceased trading on the NASDAQ on June 26, 2023. The company did not go bankrupt; instead, it achieved the ultimate goal of many micro-cap and mid-cap biopharmaceutical companies: a highly lucrative buyout. Swedish Orphan Biovitrum AB (widely known as Sobi), a global leader in rare haematology and immunology, acquired CTI BioPharma for $9.10 per share in an all-cash transaction valued at approximately $1.7 billion.
This acquisition marked the end of a long, volatile journey for CTIC stock and its shareholders. Over its multi-decade history, CTI BioPharma weathered clinical trials, regulatory rejections, clinical holds, and massive cash burn rates. However, the FDA's accelerated approval of its lead therapeutic agent, Vonjo (pacritinib), in early 2022 transformed the company from a speculative developmental play into an incredibly attractive acquisition target.
For investors searching for "ctic stock" today, understanding this transition is vital. While you can no longer buy shares of CTI BioPharma under the CTIC ticker, the underlying asset—and the commercial future of Vonjo—lives on within the larger, diversified portfolio of Sobi (STO: SOBI).
The Turbulent History of CTI BioPharma: A Journey of Biotech Perseverance
To fully understand why Sobi was willing to pay $1.7 billion for CTI BioPharma, one must look at the history of the company behind CTIC stock. Founded in 1991 as Cell Therapeutics, Inc., the company spent decades navigating the highly speculative and notoriously brutal waters of oncology and hematology drug development.
For years, CTI BioPharma struggled to find a commercial breakthrough. Early drug candidates, such as Pixuvri (pixantrone) for non-Hodgkin lymphoma, faced immense regulatory hurdles in the United States and failed to generate substantial commercial traction despite gaining conditional approval in Europe. The company was characterized by high cash burn rates, frequent dilutive share offerings, and multiple reverse stock splits designed solely to maintain its listing on the NASDAQ exchange.
The company's fortunes began to shift when it acquired the rights to pacritinib, a novel oral kinase inhibitor. However, even this path was fraught with peril. In February 2016, the U.S. Food and Drug Administration (FDA) placed a full clinical hold on pacritinib trials following reports of deaths related to intracranial hemorrhage, cardiac arrest, and heart failure in the PERSIST-1 and PERSIST-2 clinical studies. CTIC stock collapsed overnight, shedding a massive percentage of its value and leaving retail investors fearing that the company was on the brink of insolvency.
Instead of folding, CTI BioPharma’s management worked tirelessly with the FDA to analyze the trial data. They successfully demonstrated that many of the deaths in the trials were due to the advanced, terminal stage of the patients' myelofibrosis rather than direct toxicity from the drug. Furthermore, they proved that pacritinib filled an immense, unmet medical need for patients with severe thrombocytopenia. The clinical hold was lifted in early 2017, setting CTI BioPharma on a slow, grinding path to regulatory redemption. This perseverance culminated on February 28, 2022, when the FDA granted accelerated approval to Vonjo (pacritinib), vindicating the decades of research and driving the buyout that ultimately retired the CTIC ticker.
Inside the $1.7 Billion Sobi Buyout: The Deal Mechanics
On May 10, 2023, Sobi and CTI BioPharma announced a definitive agreement for Sobi to acquire CTI via an all-cash tender offer. Under the terms of the agreement, Sobi agreed to acquire all outstanding shares of CTIC stock for $9.10 per share in cash.
This price represented a massive 89% premium over CTI's closing stock price of $4.82 on May 9, 2023, and a 95% premium over its 30-day volume-weighted average price. The market reacted instantly, with CTIC stock skyrocketing to align with the buyout price, providing a major payday for long-term shareholders who had held through the stock’s historic volatility.
The transaction was executed via Sobi’s indirect wholly-owned subsidiary, Cleopatra Acquisition Corp. By late June 2023, the vast majority of CTI BioPharma’s outstanding shares had been tendered. On June 26, 2023, Sobi completed the acquisition. CTI became a wholly owned subsidiary of Sobi, and CTIC stock was promptly delisted from the NASDAQ.
For retail brokerage account holders, the transition was straightforward. Following the close of the transaction, any remaining shares of CTIC stock not explicitly tendered were automatically merged and converted into the right to receive the $9.10 cash payment per share (subject to any applicable withholding taxes). If you held CTIC stock in a brokerage account like Robinhood, Fidelity, or Charles Schwab, your shares disappeared and were replaced by cash.
The Crown Jewel: Why Sobi Bought CTI BioPharma
In the pharmaceutical industry, large acquisitions are rarely about buying offices or lab space; they are about acquiring intellectual property and commercial drug assets. For Sobi, the motivation was clear: Vonjo (pacritinib).
Myelofibrosis is a rare, life-threatening bone marrow cancer characterized by the buildup of scar tissue (fibrosis) in the marrow. This disruption impairs the body's ability to produce normal blood cells, often leading to severe anemia and thrombocytopenia (dangerously low blood platelet counts). Myelofibrosis patients are generally treated with JAK inhibitors. However, existing blockbusters on the market, such as ruxolitinib (Jakafi), can actually worsen thrombocytopenia and anemia because they non-selectively suppress bone marrow activity.
This created a massive clinical bottleneck. Patients with severe thrombocytopenia (platelet counts below 50,000 per microliter) had no safe, approved treatment options.
This is where CTI BioPharma's pacritinib (Vonjo) changed the paradigm. Pacritinib is a novel oral kinase inhibitor with a unique selectivity profile:
- JAK2 Selectivity: It targets the Janus kinase 2 (JAK2) pathway, which is mutated or overactive in myelofibrosis patients, effectively slowing disease progression.
- IRAK1 Inhibition: By targeting Interleukin-1 Receptor-Associated Kinase 1 (IRAK1), Vonjo downregulates the inflammatory cytokines that cause systemic symptoms like fatigue, bone pain, and night sweats.
- ACVR1 Inhibition: This is the game-changer. By inhibiting Activin A Receptor Type 1 (ACVR1), Vonjo suppresses hepcidin, a hormone that regulates iron absorption. Suppressing hepcidin allows the body to produce red blood cells more effectively, treating anemia instead of worsening it.
Because of this triple-action profile, Vonjo became the first and only JAK inhibitor approved specifically for myelofibrosis patients with severe thrombocytopenia (platelet counts <50,000/µL) under the FDA's accelerated approval pathway in February 2022. Sobi recognized that this niche represented a highly lucrative, underserved market segment with blockbuster potential, fitting perfectly into Sobi's existing global rare hematology franchise.
Understanding the Science: The Clinical Data That Unlocked the $1.7B Buyout
The scientific foundation that justified Sobi's $1.7 billion valuation of CTI BioPharma was built on two pivotal Phase 3 clinical trials: PERSIST-1 and PERSIST-2. These trials proved that pacritinib could safely and effectively treat myelofibrosis patients with cytopenias (low blood cell counts), a group that previously had no viable options.
The PERSIST-1 Trial
PERSIST-1 was a randomized, open-label Phase 3 trial that compared the efficacy and safety of pacritinib to "Best Available Therapy" (BAT)—excluding JAK inhibitors like ruxolitinib—in patients with active myelofibrosis. Crucially, the trial did not have a lower limit on platelet counts, meaning it included patients with severe and life-threatening thrombocytopenia.
The trial met its primary endpoint: a statistically significant percentage of patients treated with pacritinib achieved a Spleen Volume Reduction of 35% or more (SVR35) at 24 weeks. Spleen enlargement (splenomegaly) is a major complication of myelofibrosis as the spleen attempts to take over blood cell production, causing intense abdominal pressure, pain, and early satiety. Reducing spleen size directly translates to a massive improvement in patient quality of life.
The PERSIST-2 Trial
The PERSIST-2 trial went a step further. It specifically enrolled patients with myelofibrosis who had platelet counts of 100,000/µL or less, and it allowed ruxolitinib (Jakafi) to be included in the BAT comparator group. This was a direct head-to-head comparison against the reigning market standard.
The results were groundbreaking. Pacritinib was statistically superior to BAT (including ruxolitinib) in achieving both SVR35 (Spleen Volume Reduction of 35% or more) and TSS50 (Total Symptom Score reduction of 50% or more).
PERSIST-2 demonstrated that pacritinib could be administered at its full therapeutic dose (200 mg twice daily) even in patients with platelet counts under 50,000/µL. Conversely, patients on ruxolitinib in the trial frequently had to undergo dose reductions or treatment interruptions due to worsening blood counts, rendering their therapy far less effective. This clinical superiority in the cytopenic patient population gave CTI BioPharma a protected market niche that Sobi was eager to dominate.
Sobi's Stewardship of Vonjo: Commercialization and Headwinds
After taking control of CTI BioPharma and Vonjo in mid-2023, Sobi set out to scale the drug's launch globally, leveraging its established sales forces in the United States, Europe, and international markets. However, the transition from clinical-stage biotech darling to commercial heavyweight is rarely a straight line.
By 2024 and 2025, Vonjo's commercial numbers showed mixed results. While the drug steadily gained market share—holding roughly 8% of the U.S. myelofibrosis market by late 2024—it faced intense competitive pressure and commercial friction. In Q4 2024, Sobi reported Vonjo sales of SEK 416 million (approximately $39 million USD).
However, 2025 brought significant financial adjustments. In its Q3 2025 earnings report, Sobi announced a massive, non-cash impairment charge of SEK 6,612 million (roughly $630 million USD) against the product and marketing rights for Vonjo. Sobi's management explained that while Vonjo's underlying clinical demand remained resilient, its initial commercial ramp-up was slower than originally modeled during the 2023 buyout. This delay was exacerbated by heavy "gross-to-net" financial adjustments (discounts, rebates, and government pricing pressures in the U.S. market). For example, in Q3 2025, Vonjo sales fell to SEK 307 million. By Q4 2025, Vonjo recorded sales of SEK 327 million.
Despite this write-down, Sobi's leadership remains highly optimistic about Vonjo's long-term strategic potential. The impairment is a non-cash accounting adjustment reflecting a revised timeline for peak sales, not a clinical failure. Sobi continues to work on expanding global access to Vonjo, with plans to launch the drug in European and international markets to diversify its revenue stream away from its initial heavy reliance on the U.S. commercial market.
How to Invest in the Legacy of CTIC Stock Today
Because CTIC stock is delisted, retail investors who want exposure to the lucrative myelofibrosis market or the success of Vonjo must look to its parent company, Swedish Orphan Biovitrum AB (Sobi). Sobi is a highly diversified, profitable European pharmaceutical company with a robust product lineup that spans far beyond CTI BioPharma’s original portfolio.
The Investment Case for Sobi (STO: SOBI)
Unlike CTI BioPharma, which was a high-risk, single-drug biotech company, Sobi is a stable, multi-billion-dollar enterprise. If you invest in Sobi, you get exposure to a wide range of blockbuster assets:
- Haematology Dominance: Beyond Vonjo, Sobi's haematology franchise is powered by blockbuster therapies like Doptelet (for thrombocytopenia), which generated a massive SEK 1,508 million in Q4 2025 alone, and Altuvoct (for Hemophilia A), which logged SEK 1,023 million in Q4 2025. Sobi also commercializes Elocta and Alprolix in partnership with Sanofi.
- Immunology Portfolio: Sobi owns Gamifant (for hemophagocytic lymphohistiocytosis) and Kineret, alongside lucrative royalty streams from Sanofi’s U.S. sales of Beyfortus (a preventative RSV monoclonal antibody).
- Pipeline Drivers: Sobi is continuously advancing its pipeline, recently reporting positive Phase 3 results in May 2026 for its gout therapeutic pozdeutinurad, showcasing its organic growth engines.
Sobi's Financial Health and Stock Performance
In early 2026, Sobi reported its full-year 2025 financial results, highlighting total revenues of SEK 28,238 million (approximately $2.7 billion USD), representing an impressive 15% growth rate at constant exchange rates. The company's adjusted EBITA margin stood at a healthy 40%, proving its operational efficiency even after absorbing the CTI acquisition and the associated commercialization costs. Sobi has guided for continued low double-digit revenue growth in 2026.
Sobi's primary stock trades on the Nasdaq Stockholm exchange under the ticker SOBI. As of May 2026, the stock trades around SEK 441 per share, giving the company a market capitalization of approximately SEK 150 billion. Sobi stock has shown excellent long-term performance, appreciating nearly 48% over the past year.
How U.S. Investors Can Buy Sobi Shares
If you are a U.S. investor looking to recapture your exposure to CTIC stock, you cannot buy SOBI directly on the NYSE or NASDAQ. However, you have several options:
- International Brokerages: Major brokerages like Interactive Brokers, Charles Schwab, and Fidelity allow U.S. citizens to trade directly on foreign exchanges, including the Nasdaq Stockholm (OM: SOBI).
- Over-the-Counter (OTC) Market: Sobi has unsponsored American Depositary Receipts (ADRs) and shares that trade on the U.S. OTC market under tickers such as SOBIV or SOBIF. However, investors should be aware that OTC shares generally suffer from lower trading volumes and wider bid-ask spreads compared to the primary Stockholm listing.
Frequently Asked Questions (FAQs) About CTIC Stock
Is CTIC stock still trading?
No, CTIC stock is no longer active. It was officially delisted from the NASDAQ on June 26, 2023, following the completion of its $1.7 billion acquisition by Swedish Orphan Biovitrum (Sobi).
What did CTI BioPharma shareholders receive in the buyout?
Shareholders of CTI BioPharma (CTIC) received $9.10 per share in cash for each share they owned. This payment was automatically distributed to shareholders through their brokerage accounts once the merger was finalized in mid-2023.
What is Vonjo, and why was it the main driver of the acquisition?
Vonjo (pacritinib) is a highly targeted, oral kinase inhibitor developed by CTI BioPharma. It was approved by the FDA in 2022 to treat myelofibrosis in patients with severe thrombocytopenia (platelet counts below 50,000/µL). It was a revolutionary drug because, unlike competitor JAK inhibitors, it did not worsen low blood counts, making it a highly valuable asset for Sobi's hematology portfolio.
Did Sobi write down the value of Vonjo in 2025?
Yes. In Q3 2025, Sobi recorded a non-cash impairment charge of SEK 6,612 million on Vonjo due to a slower-than-expected commercial ramp-up and heavy gross-to-net adjustments in the U.S. market. However, Sobi emphasized that Vonjo remains an essential long-term strategic asset and plans to expand its commercial availability globally.
Can I still invest in CTI BioPharma's clinical pipeline?
Yes, but only indirectly by buying shares of Swedish Orphan Biovitrum AB (Sobi), which trades under the ticker SOBI on the Nasdaq Stockholm exchange. Sobi now owns and manages CTI BioPharma's entire therapeutic portfolio and pipeline.
Conclusion
The story of CTIC stock is a classic biopharmaceutical success story. CTI BioPharma survived years of clinical volatility to successfully develop Vonjo, a life-changing therapy for myelofibrosis patients. Their reward was a $1.7 billion cash buyout by Sobi in June 2023, which delivered massive immediate value to CTIC shareholders.
While the CTIC ticker is gone forever, its scientific legacy continues to thrive. Today, Sobi manages Vonjo alongside a highly profitable, diversified portfolio of rare disease therapies. For investors who believed in CTI BioPharma's vision, tracking and investing in Sobi (STO: SOBI) is the ultimate way to participate in the ongoing commercial success of pacritinib.
