On December 15, 2025 Atossa Therapeutics, Inc. (Nasdaq: ATOS) ("Atossa" or the "Company"), a clinical-stage biopharmaceutical company developing innovative medicines in oncology and other areas of high unmet need, reported four clinical trial updates on (Z)-endoxifen at the San Antonio Breast Cancer Symposium (SABCS), held December 9-12, 2025, in San Antonio, TX.

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"Clinical trial updates and data presented at SABCS 2025 reinforce our focus on the therapeutic value of (Z)-endoxifen across the breast care continuum," said Steven Quay, M.D., Ph.D., Atossa Therapeutics’ President and Chief Executive Officer. "With support from our growing body of clinical evidence, we continue to advance our high value clinical programs. Following our more streamlined pathway for our Phase 2 EVANGELINE study, we expect continued enrollment and data generation for neoadjuvant ER+/HER2- breast cancer. Finally, we are committed to advancing a low-dose treatment strategy designed to reduce mammographic breast density. High mammographic breast density has been associated with a higher risk of developing future breast cancer."

Presentation Highlights:

Initial results from RECAST DCIS: Multicenter platform trial testing active surveillance and novel endocrine therapy agents for DCIS management

Clinical significance
Early RECAST findings suggest that short-term endocrine therapy combined with MRI response assessment may identify patients with low-risk DCIS who can avoid surgery and pursue active surveillance, offering a potential pathway to reduce overtreatment while personalizing care

Key takeaways

RECAST is testing whether short-term endocrine therapy plus MRI response can identify appropriate DCIS patients for long-term active surveillance while avoiding surgery
Early results show excellent tolerability and steady enrollment, with many patients electing to continue active surveillance, suggesting feasibility of this patient-centered "window of opportunity" approach
Future work focuses on integrating imaging and molecular biomarkers to refine prediction of progression risk, guide personalized care pathways, improve patient experience and quality of life, and assess long-term outcomes including durability of active surveillance and invasive recurrence
Low dose (Z)-endoxifen in the I-SPY2 Endocrine Optimization Pilot

Clinical significance
The excellent tolerability and biologic activity of low-dose (Z)-endoxifen, demonstrated by reductions in Ki-67, MRI tumor volume, and ctDNA, support its potential as an effective neoadjuvant endocrine therapy for HR+/HER2- early breast cancer and justifies dose escalation and combination strategies to further improve patient outcomes

Key takeaways

The daily 10 mg (Z)-endoxifen dose was well tolerated, with 95% of patients completing ≥75% of therapy and low-grade side effects, demonstrating strong feasibility in an endocrine-naïve HR+/HER2- population
Biologic activity was evident, with meaningful reductions in Ki-67, MRI functional tumor volume (–72% median), and ctDNA clearance observed in 70% of patients who were initially ctDNA-positive, indicating endocrine responsiveness
Clinical impact was modest but supportive, with one mPEPI-0 outcome; the program is now escalating to 40 mg/day (targeting both ERα and PKCβ1) with or without abemaciclib to further optimize neoadjuvant endocrine therapy
(Z)-Endoxifen Maintains ERα Antagonist Function Against ESR1 Mutants via Inactive Conformation Stabilization and Reversal of Mutant ESR1-Associated Transcriptional Signatures

Clinical significance
Findings demonstrate (Z)-endoxifen as a promising therapeutic option for patients with ER+/ESR1 mutant breast cancer, a population with limited effective endocrine treatments and high unmet need

Key Takeaways

(Z)-Endoxifen shown to maintain potent ERα antagonist activity across key ESR1 mutations (Y537S, D538G) by stabilizing inactive receptor conformations, with computational, energetic, and metadynamics analyses showing ESR1 mutants still retain antagonist-compatible states
Functional assays confirmed strong suppression of ER signaling in both wild-type and mutant ESR1 backgrounds, demonstrating robust inhibitory activity even under estrogen-rich conditions and validating the mechanistic modeling findings
Transcriptomic analyses showed that (Z)-endoxifen reverses multiple mutant ESR1–associated oncogenic pathways (e.g., estrogen response, E2F, Myc) while restoring beneficial programs (oxidative phosphorylation, p53), highlighting its therapeutic potential for ER+ / ESR1 mutant breast cancer
A Randomized Phase 2 Non-Inferiority Trial of (Z)-Endoxifen + Goserelin vs Exemestane + Goserelin as a Neoadjuvant Treatment for Premenopausal Women with ER+/HER2- Breast Cancer (EVANGELINE)

Clinical Significance
(Z)-endoxifen with Ovarian Function Suppression (OFS) may offer a more tolerable and biologically potent alternative to aromatase-inhibitor (AI)-based regimens for premenopausal ER+/HER2– patients, potentially expanding endocrine therapy options and improving adherence while maintaining robust neoadjuvant efficacy

Key Takeaways

EVANGELINE is the first trial to evaluate (Z)-endoxifen with OFS as a neoadjuvant therapy for patients with premenopausal ER+/HER2– breast cancer, addressing a major unmet need for patients who cannot tolerate AI with OFS therapy
Pharmacodynamic run-in data showed strong early biologic activity, with 86% of patients achieving a Week 4 Ki-67 ≤10%, supporting the selection of 40 mg (Z)-endoxifen with OFS for Phase II, and demonstrating promising antiproliferative efficacy
The study design incorporates a Simon two-stage approach to test whether (Z)-endoxifen with OFS can meet or exceed a 65% Ki-67 response threshold, with secondary endpoints including safety, RCB, PEPI score, and MRI-based tumor response

(Press release, Atossa Therapeutics, DEC 15, 2025, View Source [SID1234661440])

On December 18, 2025 Vor Bio (Nasdaq: VOR), a clinical-stage biotechnology company transforming the treatment of autoimmune diseases, announced today that it has entered into a securities purchase agreement to sell 13,876,032 shares of its common stock at a price of $10.81 per share to a select group of institutional and accredited healthcare specialist investors in a private placement. Vor Bio anticipates the gross proceeds from the private placement to be approximately $150 million, before deducting any offering-related expenses. Vor Bio did not engage a placement agent in connection with the private placement. The private placement is expected to close on or about December 18, 2025, subject to the satisfaction of customary closing conditions.

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The financing includes participation from new and existing institutional investors, including RA Capital Management, Forbion, Frazier Life Sciences, Caligan Partners, Logos Capital, and Venrock Healthcare Capital Partners. In addition, as part of the private placement, Forbion is being granted the right to appoint one director to Vor Bio’s board of directors.

Vor Bio intends to use the net proceeds from the private placement to advance the clinical development of telitacicept, including the ongoing global Phase 3 clinical trial for myasthenia gravis and initiation of a global Phase 3 clinical trial in primary Sjögren’s disease, and for working capital and general corporate purposes.

The offer and sale of the securities to be sold in the private placement have not been registered under the Securities Act of 1933, as amended (the "Securities Act"), or any state or other applicable jurisdiction’s securities laws, and such securities may not be offered or sold in the United States absent registration or an applicable exemption from the registration requirements of the Securities Act and applicable state or other jurisdictions’ securities laws. Concurrently with entering into the securities purchase agreement, Vor Bio and the investors entered into a registration rights agreement pursuant to which Vor Bio has agreed to file a registration statement with the Securities and Exchange Commission registering the resale of the shares of common stock issued in the private placement.

This press release shall not constitute an offer to sell or the solicitation of an offer to buy these securities, nor shall there be any sale of these securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of any such jurisdiction.

(Press release, Vor BioPharma, DEC 15, 2025, View Source [SID1234661538])

On December 15, 2025 FibroGen, Inc. (NASDAQ: FGEN) reported that the Office of Orphan Products Development of the U.S. Food and Drug Administration (FDA) has granted roxadustat Orphan Drug Designation for the treatment of myelodysplastic syndromes (MDS).

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"The Orphan Drug Designation granted to roxadustat for MDS underscores the significant treatment gap in this indication, and highlights patients’ need for additional convenient treatments that can provide durable response," said Thane Wettig, Chief Executive Officer of FibroGen. "Roxadustat showed an improvement in transfusion-independence in a subset of patients with high transfusion burden in a post-hoc analysis from the Phase 3 MATTHERHORN trial, which along with its favorable tolerability profile and oral route of administration has the ability to set it apart from current second-line treatments. Our team is finalizing the Phase 3 protocol in this patient population for submission to the FDA in the fourth quarter of 2025."

There are approximately 58,000 patients diagnosed with LR-MDS in the U.S. with 85% of them suffering from anemia. Anemia in patients with MDS is associated with increased risk of cardiovascular complications and the need for blood transfusions. Transfusion-dependent patients suffer higher rates of complications and decreased quality of life. Current first-line treatments lead to transfusion independence in less than 50% of patients and relief is often temporary with limited options for second line and beyond treatments. In a post-hoc analysis from the Phase 3 MATTERHORN trial, roxadustat demonstrated transfusion independence benefits compared to placebo in patients with high transfusion burden.

The FDA Orphan Drug Designation is granted to drugs intended for the treatment, diagnosis, or prevention of rare diseases that affect fewer than 200,000 people in the U.S. Benefits of the designation may include exemption from certain FDA fees, financial incentives for qualified clinical development, and seven years of market exclusivity in the U.S. following drug approval.

About Myelodysplastic Syndromes Anemia
Myelodysplastic syndromes (MDS) are a group of disorders characterized by dysfunctional progenitor blood cells and stem cells, resulting in chronic anemia in most patients. Annual incidence rates of MDS are estimated to be 4.9/100,000 adults in the U.S, of which 77% are considered lower-risk MDS. Approximately 80% of patients with MDS have anemia at the time of diagnosis, and around 60% of patients with MDS will experience severe anemia (hemoglobin <8 g/dL) at some point during the course of their disease. Anemia in patients with MDS is associated with increased risk of cardiovascular complications and the need for blood transfusion. Approximately 50% of patients with MDS require regular red blood cell transfusions. Transfusion-dependent MDS patients suffer higher rates of cardiac events, infections, and iron overload with the related complications. In addition, anemia frequently leads to significant fatigue, cognitive dysfunction, and decreased quality of life. Today, patients are routinely treated with erythropoiesis-stimulating agents (ESAs), luspatercept, imetelstat, or lenalidomide in lower-risk MDS with isolated del(5q), and hypomethylating agents (HMAs) in higher-risk disease. Only 35-40% of patients respond to current treatments and the durability of response is short. Moreover, these treatments are challenging to dose-calibrate and can only be administered via subcutaneous injection or through IV infusion. There remains a high unmet need for the treatment of anemia associated with MDS, and new strategies that provide durable response and the convenience of oral administration are highly desired in managing patients with MDS.

About Roxadustat
Roxadustat, an oral medication, is the first in a new class of medicines comprising HIF-PH inhibitors that promote erythropoiesis, or red blood cell production, through increased endogenous production of erythropoietin, improved iron absorption and mobilization, and downregulation of hepcidin.

Roxadustat is approved in Europe, Japan, and numerous other countries for the treatment of anemia of CKD in adult patients on dialysis (DD) and not on dialysis (NDD). FibroGen has the sole rights to roxadustat in the United States, Canada, Mexico, and in all markets not held by AstraZeneca or licensed to Astellas. Astellas and FibroGen are collaborating on the commercialization of roxadustat for the treatment of anemia in territories including Japan, Europe, Turkey, Russia, and the Commonwealth of Independent States, the Middle East, and South Africa.

(Press release, FibroGen, DEC 15, 2025, View Source [SID1234661421])

On December 15, 2025 TuHURA Biosciences, Inc. (NASDAQ:HURA) ("TuHURA" or the "Company"), a Phase 3 immuno-oncology company developing novel therapeutics to overcome resistance to cancer immunotherapy, reported that Kintara’s REM-001 clinical trial of ten metastatic cutaneous breast cancer patients met its primary endpoint demonstrating safety with signs of clinical efficacy following eight weeks of follow-up for such patients.

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Pursuant to the terms of the Contingent Value Rights Agreement dated as of October 18, 2024, by and between TuHURA Biosciences, Inc. and the rights agent, Equiniti Trust Company, LLC (the "CVR Agreement"), as a result of the trial and the completion of the follow-up, the milestone required for the release of an aggregate of 1,539,958 shares of TuHURA common stock to legacy Kintara Therapeutics stockholders has been achieved. The holders of CVRs are entitled to receive shares of TuHURA common stock, subject to the terms of the CVR Agreement and any applicable withholding. Pursuant to the CVR Agreement, the shares of TuHURA common stock are expected to be distributed to the CVR holders within the next ten business days.

(Press release, TuHURA Biosciences, DEC 15, 2025, View Source [SID1234661441])

On December 15, 2025 Greenwich LifeSciences, Inc. (Nasdaq: GLSI) (the "Company"), a clinical-stage biopharmaceutical company focused on its Phase III clinical trial, FLAMINGO-01, which is evaluating GLSI-100, an immunotherapy to prevent breast cancer recurrences, reported an approximately 80% recurrence rate reduction in the open label non-HLA-A*02 arm of FLAMINGO-01.

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A preliminary analysis of recurrence rates by two methods to estimate the reduction in recurrence rate shows an approximately 80% reduction in recurrence rate in the fully enrolled, 250 patient non-HLA-A*02 arm of FLAMINGO-01. This arm does not have a direct placebo comparator arm, thus these two methods were used.
This observation is trending similarly to the Phase IIb trial results and hazard ratio where HLA-A*02 patients were treated and where breast cancer recurrences were reduced up to 80% compared to a 20-50% reduction in recurrence rate by other approved products. See the summary of the Phase IIb results below.
The first non-HLA-A*02 patient has completed the 11 primary and booster vaccinations over the first 3 years.

In addition to announcing this first analysis of the recurrence rate data in the open label non-HLA-A*02 arm of FLAMINGO-01, the Company previously reported promising observations showing that the immune response at baseline prior to any GLSI-100 treatment, the increasing immune response during the primary immunization series, and the safety profile of non-HLA-A*02 patients is trending similarly to the HLA-A*02 arms of FLAMINGO-01 and to the Phase IIb study.

The Primary Immunization Series (PIS), which includes the first 6 GLSI-100 injections over the first 6 months and is required to reach peak protection, is followed by 5 booster injections given every 6 months to prolong the immune response, thereby providing longer-term protection.

In the 250 patient non-HLA-A*02 data set, all patients received GLSI-100, which is 5 times more treated patients and recurrence rate data than the approximately 50 patients treated in the Phase IIb trial. Since the 250 non-HLA-A*02 patients do not have a placebo arm for a direct comparison, the following two methods were used, yielding the 80% reduction in recurrence rate observation:

Method 1: The recurrence rate of these 250 treated patients after completing the PIS was compared to the expected historical recurrence rate per year reported for this population in the Katherine study who received TDM1 (Kadcyla), which is about 3.5-4% recurrences per year or higher in the initial years of the Katherine study. The majority of the treated patients in FLAMINGO-01 also received TDM1 followed by GLSI-100. The data suggests an approximately 80% reduction in recurrence rate after the GLSI-100 PIS is completed as compared to the TDM1 arm of the Katherine study at a similar timepoint.
Method 2: The recurrence rate during the first 6 months of vaccination or PIS period when the patient may not be fully protected or protected at all, which covered an exposure period of 100 patient years, was compared to the recurrence rate after the PIS is completed and after peak immunity is believed to be achieved, which covered an exposure period of 132 patient years. The exposure period (patient years) is defined as the cumulative number of years all patients are followed in a period. The data suggests that the peak immunity is lowering the recurrence rate by approximately 80% after the PIS is completed as compared to the recurrence rate during the PIS period.
For the first 6 months of vaccination or PIS, the theoretical maximum patient years would be 250 patients at 0.5 years each or 125 patient years. Thus 100 completed patient years represents 80% of the maximum potential patient years and within 3 to 6 months all vaccinations during this period may be completed.
For the period after the PIS is completed, the theoretical maximum patient years would be 250 patients at 3.5 years of follow-up each or 875 patient years. Thus 132 completed patient years represents 15% of the maximum potential patient years and represents an average of 9 months of follow-up time after the PIS for patients who have completed the PIS.
Analysis of the open label data from FLAMINGO-01 has been conducted in a manner that maintains the study blind. The open label recurrence rate, immune response, and safety data is based on the patients enrolled to date in FLAMINGO-01 and the data provided by the clinical sites so far, which is not completed or fully reviewed, and is thus preliminary. While comparing any preliminary FLAMINGO-01 data to the Phase IIb clinical trial data may be possible, these preliminary results are not a prediction of future results, and the results at the end of the study may differ.

CEO Snehal Patel commented, "We are very excited to announce in our 100th press release since going public that the first patient has completed the full primary and booster vaccination series in FLAMINGO-01. We are equally excited to see a positive trend in the recurrence rate in the non-HLA-A*02 arm of FLAMINGO-01, as assessed multiple ways, that is trending similarly to the Phase IIb trial results where HLA-A*02 patients were treated. Despite these being preliminary results that will mature and can change with time, seeing a reduction in expected recurrence rates that is trending towards a low HR of 0.2, which represents an 80% reduction in recurrence rate, is very encouraging and which is why along with the similarly promising safety and immune response data to date, we will seek to continue to treat non-HLA-A*02 patients in a placebo controlled manner in the study. We will continue to analyze the data and may provide updates at any time."

Previously Published Phase IIb Data

In the prospective, randomized, single-blinded, placebo-controlled, multi-center (16 sites led by MD Anderson Cancer Center) Phase IIb clinical trial of HLA-A*02 breast cancer patients, 46 HER2/neu 3+ over-expressor patients were treated with GLSI-100, and 50 placebo patients were treated with GM-CSF alone. After 5 years of follow-up, there was an 80% or greater reduction in cancer recurrences in the HER2/neu 3+ patients who were treated with GLSI-100, followed, and remained disease free over the first 6 months, which we believe is the time required to reach peak immunity and thus maximum efficacy and protection. The Phase IIb results can be summarized as follows:

80% or greater reduction in metastatic breast cancer recurrence rate over 5 years of follow-up with a peak immune response at 6 months and well-tolerated safety profile.
The PIS elicited a potent immune response as measured by local skin tests and immunological assays.

About FLAMINGO-01 and GLSI-100

FLAMINGO-01 (NCT05232916) is a Phase III clinical trial designed to evaluate the safety and efficacy of GLSI-100 (GP2 + GM-CSF) in HER2 positive breast cancer patients who had residual disease or high-risk pathologic complete response at surgery and who have completed both neoadjuvant and postoperative adjuvant trastuzumab based treatment. The trial is led by Baylor College of Medicine and currently includes US and European clinical sites from university-based hospitals and academic and cooperative networks with plans to open up to 150 sites globally. In the double-blinded arms of the Phase III trial, approximately 500 HLA-A*02 patients are planned to be randomized to GLSI-100 or placebo, and up to 250 patients of other HLA types are planned to be treated with GLSI-100 in a third arm. The trial has been designed to detect a hazard ratio of 0.3 in invasive breast cancer-free survival, where 28 events will be required. An interim analysis for superiority and futility will be conducted when at least half of those events, 14, have occurred. This sample size provides 80% power if the annual rate of events in placebo-treated subjects is 2.4% or greater.

For more information on FLAMINGO-01, please visit the Company’s website here and clinicaltrials.gov here. Contact information and an interactive map of the majority of participating clinical sites can be viewed under the "Contacts and Locations" section. Please note that the interactive map is not viewable on mobile screens. Related questions and participation interest can be emailed to: [email protected]

About Breast Cancer and HER2/neu Positivity

One in eight U.S. women will develop invasive breast cancer over her lifetime, with approximately 300,000 new breast cancer patients and 4 million breast cancer survivors. HER2 (human epidermal growth factor receptor 2) protein is a cell surface receptor protein that is expressed in a variety of common cancers, including in 75% of breast cancers at low (1+), intermediate (2+), and high (3+ or over-expressor) levels.

(Press release, Greenwich LifeSciences, DEC 15, 2025, View Source [SID1234661422])