Pembrolizumab

Solstice Oncology has secured $225 million in series A funds to advance a next-gen immunotherapy that the biotech hopes will turn “darkness to light” for cancer care. The company licensed the Fc-enhanced cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) antibody, called porustobart, from China's Harbour BioMed back when Boston-based Solstice was founded in February. In return for a $105 million upfront package, Solstice can develop and commercialize the drug outside of China and has already taken porustobart into phase 2 development for microsatellite stable (MSS) stage II and III colon cancer. Solstice noted in its Sept. 9 release that this patient population has “yet to benefit from immunotherapy.” The series A—which was led by RA Capital Management and featured the likes of Canaan Partners and Forbion—will be used to fund the phase 2 trial testing porustobart with Keytruda. The study is due to start enrolling this year for a readout in the second half of 2027. Solstice also plans to develop porustobart in another, as-yet-undisclosed indication. MSS colon cancer is a cold tumor, meaning the tumor doesn't trigger a strong immune response and isn't impacted by most immunotherapies, with the standard of care consisting of surgery and chemotherapy. Solstice’s molecule is designed to work with and widen the response of PD-1s like Keytruda by releasing a second brake on the immune system and depleting the immunosuppressive regulatory T cells that shield tumors from attack. By pairing porustobart with Keytruda, Solstice CEO Caroline Loew, Ph.D., told Fierce that the company is aiming for a “synergistic response” that is especially effective in MSS colon cancer. “We know that an anti-PD-L1 by itself has a 0% response rate in this setting,” Loew explained in an interview. “PD-L1 plus first-generation CTLA-4 is about up to 5% in this setting.” “If we add our treatment, we're seeing responses at 30%,” said Loew, referencing Harbour’s phase 1b trial for the porustobart, where patients stayed in remission (PDF) for an average of 8.4 months. “There's a big difference by putting the two together, so you want to use all of the mechanisms you can to your advantage,” the CEO added. Porustobart is also being designed with a shorter half-life than existing treatments—four to five days compared to roughly two to three weeks for existing CTLA-4 antibodies—which Solstice believes can make dosing more flexible, reducing the frequency and duration of immune-related adverse events. “We're essentially unlocking this potential of CTLA-4 to be practice-changing, and that's a huge deal,” Loew said. “The first generation of immunotherapy had incredible outcomes for patients, and we're taking that next step of opening up the aperture for more patients to have access to immunotherapy.” In addition to being designed as a unique second-generation CTLA-4 antibody, porustobart is also going to be administered in the neoadjuvant setting, before any surgical intervention. “At that point, your immune system is intact,” Loew said. “You haven't developed any resistance, and the tumor itself is visible to the immune system. If you can eradicate that micrometastatic disease, that's where you drive cure,” the CEO added. Anti-CTLA-4 checkpoint inhibitors have proven their worth in oncology in the form of Bristol Myers Squibb’s blockbuster Yervoy and AstraZeneca’s Imjudo. Yervoy is approved for unresectable or metastatic microsatellite instability-high or mismatch repair deficient colorectal cancer, although immune-mediated toxicities give the antibody a narrow therapeutic window. Solstice isn't alone in aiming a CTLA-4 inhibitor specifically at colon cancer. Agenus is preparing to take a combination of its CTLA-4 inhibitor botensilimab and its anti-PD-1 antibody balstilimab into a phase 3 study for patients with MSS colon cancer, a market that Agenus said could be worth $7 billion in the U.S. alone. Loew said that the name Solstice represents a turning point and a moment of transformation from darkness to light for cancer care, although she noted that “most things fail” and has the experience to prove it. She previously led Mural Oncology, which spun out of Alkermes with $275 million in 2023. Two years later, Mural laid off 90% of its staff after its IL-2 variant failed its phase 3 trial, and Mural was purchased by Xoma Royalty last year. Loew, whose career also included a stint as head of R&D strategy and planning for BMS, told Fierce that she was drawn back into the biotech startup world because of her belief in porustobart's mechanism, backed up by clinical data with “responses that haven't been seen before” and the potential to use the therapy in a neoadjuvant setting. “When you put those three things together, you're like, ‘Wow, this is de-risked, and there's a potential to make a big difference in what's a very underserved population,’” she said. The content above comes from the network. if any infringement, please contact us to modify.

TAMPA, Fla., Sept. 14, 2026 /PRNewswire/ -- TuHURA Biosciences, Inc. (NASDAQ:HURA) ("TuHURA" or the "Company"), a Phase 3 immuno-oncology company developing novel therapeutics to overcome resistance to cancer immunotherapy, today announced that the U.S. Food and Drug Administration (FDA) has given clearance to TuHURA's Investigational New Drug (IND) application for its TBS-2025 VISTA-inhibiting antibody for molecularly defined subsets of Acute Myeloid Leukemia (AML) and other blood-related cancers. The "Study May Proceed" notice from the FDA allows the Company to examine TBS-2025 in a Phase 1b study evaluating the safety and potential efficacy of monotherapy at different doses in patients with relapsed/refractory (r/r) mutNPM1 AML who have failed to respond to or relapsed after menin inhibitor therapy. Following review of the safety data with the FDA, the study is expected to progress to the dose-optimization stage of the trial to determine a safe and biologically effective dose. Patients with r/r mutNPM1 AML who fail menin inhibitor therapy have no approved or effective treatments and represent an unmet medical need. If TBS-2025 results in encouraging response rates during the dose optimization stage of the study, the Company will explore with the FDA the potential expansion of the trial in consideration for the opportunity for accelerated approval. "As the only known company to advance a VISTA-inhibiting mAb through the FDA's IND process into a Phase 1b study in mutNPM1 AML, this is a major milestone for the Company and a testament to our commitment to advancing novel therapies to address the unmet needs of patients with AML," said Dr. James Bianco, President and Chief Executive Officer of TuHURA Biosciences. "Research has shown that patients whose leukemic cells express VISTA have a poor response to therapy and significantly shorter survival. Studies have demonstrated that TBS-2025's ability to block VISTA on leukemic cells has resulted in dramatic improvement in survival in studies of murine models of human AML, and we hope to translate this promising underlying science into a potentially safe and effective new treatment for patients with AML. We are excited for this next phase of our growth and by what it could mean for patients with AML." About TBS-2025 TBS-2025 is a unique VISTA-inhibiting monoclonal antibody. VISTA is a novel checkpoint expressed on quiescent (resting) T cells and highly expressed on myeloid cells, notably myeloid-derived suppressor cells (MDSCs). Scientific evidence demonstrates that mutNPM1 drives the expression of VISTA on leukemic blasts, which is reported to be the primary mechanism by which AML escapes recognition by the patient's immune system, resulting in low response rates of short duration following current therapies, including recently approved menin inhibitors. When VSIR, the gene that encodes for VISTA, is edited not to produce VISTA in murine models of mutNPM1 AML, an immune response is observed and survival is enhanced. Similarly, in a murine model of AML, TBS-2025 resulted in an increase in survival comparable to the intensive chemotherapy regimen that is currently used in front line treatment of patients with AML. When combined with intensive chemotherapy, survival was markedly improved. Collectively, these translational data underscore the potential for TBS-2025 in the treatment of patients with AML. About TuHURA Biosciences, Inc. TuHURA Biosciences, Inc. (Nasdaq: HURA) is a Phase 3 immuno-oncology company developing novel technologies to overcome primary and acquired resistance to cancer immunotherapy, two of the most common reasons cancer immunotherapies fail to work or stop working in the majority of patients with cancer. TuHURA's lead innate immune agonist, IFx-2.0, is designed to overcome primary resistance to checkpoint inhibitors. TuHURA has initiated a single randomized placebo-controlled Phase 3 registration trial of IFx-2.0 administered as an adjunctive therapy to Keytruda® (pembrolizumab) compared to Keytruda® plus placebo in first-line treatment for advanced or metastatic Merkel Cell Carcinoma. In addition to its innate immune agonist product candidates, TuHURA is developing TBS-2025, a VISTA-inhibiting mAb moving into Phase 1b/2 in mutNPM1 r/r AML, a molecularly defined subgroup of patients with AML. In addition, TuHURA is leveraging its Delta Opioid Receptor technology to develop first-in-class, bi-specific, bi-functional antibody drug conjugates (ADCs) targeting Myeloid-Derived Suppressor Cells to inhibit their immune-suppressing effects on the tumor microenvironment to prevent T cell exhaustion and acquired resistance to checkpoint inhibitors and cellular therapies. For more information, please visit and connect with TuHURA on Facebook, X, and LinkedIn. Cautionary Statement Regarding Forward-Looking Statements This press release contains certain "forward-looking statements" within the meaning of, and subject to the safe harbor created by, Section 27A of the Securities Act of 1933, as amended, Section 21E of the Securities Exchange Act of 1934, as amended, and the Private Securities Litigation Reform Act of 1995. These forward-looking statements are based only on our current beliefs, expectations and assumptions regarding the future of our business, future plans and strategies, projections, anticipated events and other future conditions. In some cases, you can identify these statements by forward-looking words such as "believe," "may," "will," "estimate," "continue," "anticipate," "intend," "could," "should," "would," "project," "plan," "expect," "goal," "seek," "future," "likely," or the negative or plural of these words or similar expressions. Our statements in this press release regarding our planned Phase1b study of TBS-2025 is an example of such forward-looking statements. You are cautioned that such statements are not guarantees of future performance and that actual results or developments may differ materially from those set forth in these forward-looking statements. Factors that could cause actual results to differ materially from these forward-looking statements include, among others, the risks associated conducting the planned Phase 1 study of TBS-2025 and the general risks associated with continuing the development of TBS-2025; risks related to patient enrollment, trial design, data outcomes and regulatory interactions; uncertainty regarding the timing and likelihood of regulatory approvals; and the other risks described from time to time in detail in the Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2025, as filed on March 31, 2026, and TuHURA's other reports and filings with the SEC from time to time, which are available on TuHURA's website and at . The forward-looking statements and other information contained in this press release are made as of the date hereof, and TuHURA does not undertake any obligation to update publicly or revise any forward-looking statements or information, whether as a result of new information, future events or otherwise, unless so required by applicable securities laws. Investor Contact: Monique Kosse Gilmartin Group [email protected] SOURCE TuHURA Biosciences, Inc. 21% more press release views with Request a Demo