Retifanlimab

PFS of 4.2 months in Phase 2 ADC resistant patients receiving Bria-IMT™ pivotal Phase 3 formulation is twice that of controls in similar studies PFS results reinforced by larger number of prior treatments in Bria-IMT™ population than in comparable studies Bria-IMT™ PFS compares favorably to their most recent treatment PFS in 48% of patients Clinical benefit rate of 56% in evaluable patients71% intracranial objective response rate (iORR) in heavily pretreated patientsFindings support clinical efficacy of Bria-IMT™ and highlight its significant potential in managing CNS metastatic disease in advanced breast cancerAdditional preclinical anti-cancer data of Bria-OTS+™ and Bria-PROS+™ will be presented tomorrow 9:00 AM - 12:30 PM PST; Abstract Presentation Number: 6753 PHILADELPHIA and VANCOUVER, British Columbia, April 09, 2024 (GLOBE NEWSWIRE) -- BriaCell Therapeutics Corp. (Nasdaq: BCTX, BCTXW) (TSX: BCT) (“BriaCell” or the “Company”), a clinical-stage biotechnology company that develops novel immunotherapies to transform cancer care, is presenting positive clinical data from its lead product candidate, Bria-IMT™, in two posters of its three poster sessions during the 2024 American Association for Cancer Research (AACR) Annual Meeting held from April 5-10 at San Diego Convention Center, San Diego, CA. “We are extremely impressed by the unprecedented survival and clinical benefit data for Bria-IMT™ in patients who have failed ADCs,” stated lead author Chaitali S. Nangia, MD, Partner at Hoag Medical Group. “ADCs are the latest treatments for very difficult-to-treat advanced metastatic breast cancer. However, some patients experience resistance with rapid disease progression. To our knowledge, there are no effective treatment options in this patient population for whom the progression-free survival prognosis is only a few weeks. Finding an alternative well-tolerated treatment option that is effective is a matter of life and death for these patients.” “Our clinical data further validates Bria-IMT™’s novel mechanism of action to generate potent immune responses in breast cancer patients who failed ADCs leading to clinically relevant survival and treatment benefit in these patients,” commented Dr. Giuseppe Del Priore, BriaCell’s CMO. “We look forward to building upon the body of evidence with additional clinical data in the coming months from the ongoing pivotal registration trial.” “We are excited about the safety and efficacy data to date with Bria-IMT™ and expect that Bria-IMT™ will generate positive effects on survival and clinical benefit in the Phase 3 study in advanced breast cancer patients whose medical needs remain unmet,” commented Dr. William V. Williams, BriaCell’s President and CEO. The posters are summarized below and linked here: https://briacell.com/scientific-publications/. Poster 1 – Title: Efficacy of Bria-IMT™ regimen in inducing CNS metastasis regressionAbstract Presentation Number: CT204 Superior clinical benefit of Bria-IMT™ regimen - alone or combined with an immune check point inhibitor (CPI) in advanced breast cancer patients with CNS metastatic disease Clinical efficacy: 71% (5/7) intracranial objective response rate (iORR), defined as the percentage of patients who achieve a complete response (complete disappearance) or partial response (volume reduction of 30% or more) in intracranial tumors, achieved in patients with central nervous system (CNS) metastases treated with the Bria-IMT™ regimen, either alone or in combination with an immune checkpoint inhibitor (i.e. PD-1 inhibitor pembrolizumab or retifanlimab). These patients failed multiple prior treatments including 2 antibody-drug conjugates in one case. Clinical benefit is observed across all subsets of breast cancer.Safety profile: Absence of both interstitial lung disease (ILD), a common serious adverse event with ADCs, and no Bria-IMT™-related treatment discontinuations underscore Bria-IMT™'s excellent tolerability and favorable safety profile. In summary, Bria-IMT™’s tumor reductions observed in all breast cancer subtypes in patients with intracranial disease underlines its potential clinical effectiveness in managing CNS metastatic disease in advanced breast cancer. BriaCell will continue to monitor the data in this subgroup of patients including a pre-planned subgroup analysis in the current pivotal Phase 3 study in advanced metastatic breast cancer. Treatment of patients with CNS metastatic disease represents a potential additional indication for market approval of Bria-IMT™. Poster 2 – Title: Efficacy and safety of SV-BR-1-GM after progression on ADC in metastatic breast cancer patientsAbstract Presentation Number: CT206 Notable progression-free survival benefit of Bria-IMT™ in ADC resistant advanced metastatic breast cancer Phase 2 clinical data of the Bria-IMT™ regimen in 23 advanced metastatic breast cancer patients who failed multiple prior treatments including ADCs and CPIs (median of 6 prior treatments) are presented. Progression-free Survival Benefit: Median progression free survival (PFS), defined as the length of time during which a patient’s cancer does not get worse, in heavily pre-treated patients of 3.5 months is comparable to that seen in similar studies in patients with a history of fewer prior treatments (median of 4)1,2. Similarly, median PFS of 4.2 months in patients receiving the Bria-IMT™ pivotal phase 3 formulation is approximately twice the PFS figures reported for treatment of physician’s choice (TPC) in other similar studies. These PFS results suggest superior clinical efficacy considering the larger number of prior treatments in Bria-IMT™ patients vs those of the other studies.Clinical efficacy: PFS is similar or better than that of the last regimen in 48% (11/23) of the patients suggesting Bria-IMT™ effectiveness in delivering clinical and survival benefits in these patients. Additionally, a clinical benefit rate (CBR), defined as percentage of patients whose disease shrinks or remains stable over a certain time, of 56% is observed in evaluable patients further highlighting clinical benefit.Subset specific clinical benefits: Study data to date suggests clinical benefit for multiple breast cancer subtypes including HR+/HER2- (the most common breast cancer subtype, testing positive for estrogen and/or progesterone receptors and negative for human epidermal growth factor receptor 2 or HER2) with a CBR following treatment, of 63% (5 of 8 patients); HER2+ subtype (a positive test for HER2) with a 100% CBR (2 of 2 patients) and HR-/HER2 low subtype (a negative test for estrogen and/or progesterone receptor and a negative test for HER2) showing a CBR of 66% (2 of 3 patients).Safety profile: There are no incidents of interstitial lung disease - a well-documented serious adverse event associated with ADCs, - in either ADC naïve or ADC treated patients, and no treatment-related discontinuations of Bria-IMT™. In summary, the data to date shows that Bria-IMT™ provides prolonged progression-free survival and clinical benefits in heavily pre-treated, ADC resistant breast cancer patients compared with those in other similar studies. BriaCell will be monitoring ADC resistant patients in its ongoing pivotal Phase 3 study of Bria-IMT™ and CPI in advanced metastatic breast cancer. ________________________1 Cortes J et al. Eribulin monotherapy versus treatment of physician’s choice in patients with metastatic breast cancer (EMBRACE): a phase 3 open-label randomized study. Lancet (2011) 377: 914–232 Bardia A et al. Final results from the randomized phase III ASCENT clinical trial in metastatic triple-negative breast cancer and association of outcomes by human epidermal growth factor receptor 2 and trophoblast cell surface antigen 2 expression. J Clin Oncol (2024) 00:1-7 About BriaCell Therapeutics Corp. BriaCell is a clinical-stage biotechnology company that develops novel immunotherapies to transform cancer care. More information is available at https://briacell.com/. Safe Harbor This press release contains “forward-looking statements” that are subject to substantial risks and uncertainties. All statements, other than statements of historical fact, contained in this press release are forward-looking statements. Forward-looking statements contained in this press release may be identified by the use of words such as “anticipate,” “believe,” “contemplate,” “could,” “estimate,” “expect,” “intend,” “seek,” “may,” “might,” “plan,” “potential,” “predict,” “project,” “target,” “aim,” “should,” “will,” “would,” or the negative of these words or other similar expressions, although not all forward-looking statements contain these words. Forward-looking statements, including those about presenting three posters at the 2024 AACR, and the contents of such posters; the positive clinical data from BriaCell’s Bria-IMT™ being presented in two posters during the 2024 AACR; the clinical efficacy of Bria-IMT™ and its potential clinical effectiveness in managing CNS metastatic disease in advanced breast cancer; the unprecedented survival and clinical benefit data for Bria-IMT™; Bria-IMT™’s ability to generate potent immune responses in breast cancer patients who failed ADCs, leading to clinically relevant survival and treatment benefit; BriaCell’s ability to build upon their current body of evidence with additional clinical data in the coming months from the ongoing registration trial; Bria-IMT™’s ability to generate positive effects on survival and clinical benefit in the Phase 3 study in advanced breast cancer patients; Bria-IMT™'s tolerability and favorable safety profile; Bria-IMT™'s significant potential in managing CNS metastatic disease in advanced breast cancer; BriaCell monitoring the data in a subgroup of patients including a pre-planned subgroup analysis in the current pivotal Phase 3 study in advanced metastatic breast cancer; the treatment of patients with CNS metastatic disease representing a potential additional indication for market approval of Bria-IMT™; Bria-IMT™’s effectiveness in delivering clinical and survival benefits in patients; the Bria-IMT™ data representing a clinical benefit for multiple breast cancer subtypes including HR+/HER2; and BriaCell’s monitoring of ADC resistant patients in their ongoing pivotal Phase 3 study of Bria-IMT™ and CPI in advanced metastatic breast cancer, are based on BriaCell’s current expectations and are subject to inherent uncertainties, risks, and assumptions that are difficult to predict. Further, certain forward-looking statements are based on assumptions as to future events that may not prove to be accurate. These and other risks and uncertainties are described more fully under the heading “Risks and Uncertainties” in the Company's most recent Management’s Discussion and Analysis, under the heading "Risk Factors" in the Company's most recent Annual Information Form, and under “Risks and Uncertainties” in the Company's other filings with the Canadian securities regulatory authorities and the U.S. Securities and Exchange Commission, all of which are available under the Company's profiles on SEDAR+ at www.sedarplus.ca and on EDGAR at www.sec.gov. Forward-looking statements contained in this announcement are made as of this date, and BriaCell Therapeutics Corp. undertakes no duty to update such information except as required under applicable law. Neither the Toronto Stock Exchange nor its Regulation Services Provider (as that term is defined in the policies of the Toronto Stock Exchange) accepts responsibility for the adequacy or accuracy of this release. Contact Information Company Contact:William V. Williams, MDPresident & CEO1-888-485-6340info@briacell.com Media Relations:Jules AbrahamCORE IRjulesa@coreir.com Investor Relations Contact:CORE IRinvestors@briacell.com

Early interim safety data from Phase 2 TAMARACK study, including comparison to retrospective analysis from Phase 1 study,as submitted in ASCO abstract Company plans to provide updated interim data, including safety and preliminary efficacy, by May 31 Company plans to provide additional clinical data – including rPFS – in the Fall of 2024 ROCKVILLE, MD, April 03, 2024 (GLOBE NEWSWIRE) -- MacroGenics, Inc., (NASDAQ: MGNX), a biopharmaceutical company focused on discovering, developing, manufacturing and commercializing innovative antibody-based therapeutics for the treatment of cancer, today provided an update on the Phase 2 TAMARACK study of vobramitamab duocarmazine (vobra duo, previously known as MGC018) in patients with metastatic castration-resistant prostate cancer (mCRPC). As previously disclosed, safety data from the Company’s ongoing TAMARACK Phase 2 study was submitted in early February to the American Society of Clinical Oncology (ASCO) for presentation at the upcoming Annual Meeting that begins May 31. The abstract containing this early interim data, based on a January 4, 2024 data cut-off, was not accepted. The submitted abstract is provided below. “While the TAMARACK data will not be presented at the ASCO Annual Meeting, we intend to maintain our previously disclosed plan to share further TAMARACK interim data, including updated safety and preliminary efficacy, by the end of May,” said Scott Koenig, M.D., Ph.D., President and Chief Executive Officer. “This updated information will be based upon a future data cut-off. In addition, we still anticipate presenting updated clinical data – including radiographic progression-free survival, or rPFS, the study’s primary endpoint – in the Fall of 2024.” Abstract as submitted on February 6, 2024: “Title Vobramitamab duocarmazine (vobra duo), a B7-H3 directed antibody drug conjugate (ADC) in metastatic castration resistant prostate cancer (mCRPC): Early data from the Phase 2 TAMARACK study. Background Vobra duo (MGC018) is an ADC with a duocarmycin-based DNA-alkylating payload. Vobra duo targets B7-H3, which is highly expressed in multiple tumor types including prostate cancer and has limited expression in normal tissue. Phase 1 testing (NCT03729596) of vobra duo at 3.0 mg/kg Q3W demonstrated anti-tumor activity in mCRPC, although adverse events resulted in high rates of dose modifications and early treatment discontinuation. Lowering the starting dose may improve tolerability, extend treatment duration, and enhance effectiveness. Methods TAMARACK is an ongoing randomized, open-label, Phase 2 dose selection study assessing the efficacy, safety, and tolerability of two dose levels of vobra duo (2.0 mg/kg and 2.7 mg/kg IV Q4W). The study enrolled patients (pts) with mCRPC previously treated with abiraterone, enzalutamide, or apalutamide; prior docetaxel was allowed. The primary endpoint is investigator-assessed PFS at 6 months. Results At data cutoff (Jan 4, 2024), 182 pts with mCRPC enrolled on TAMARACK, of which 177 received vobra duo. Enrolled pts were 46 to 89 years of age (median 70.5) with ECOG performance status ≤ 2. Thirty (16.5%) had visceral disease at baseline, 109 (59.9%) had RECIST-evaluable disease, and 98 (53.8%) received prior docetaxel. At this early data cut, pts have received a median of 3 (range 1 to 7) cycles of vobra duo; treatment is ongoing in 156 (85.7%). A summary of treatment-emergent adverse events (TEAEs) is presented below. Vobra duo 2.0 mg/kg (n=91) Vobra duo 2.7 mg/kg (n=86) Any TEAE 85 (93.4%) 82 (95.3%) TEAE Grade ≥ 3 23 (25.3%) 27 (31.4%) Serious AE 11 (12.1%) 17 (19.8%) Drug Interruption due to AE 10 (11.0%) 16 (18.6%) Drug Discontinuation due to AE 4 (4.4%) 2 (2.3%) Fatal AE 0 0 The most common (≥10%) TEAEs regardless of dose were asthenia (40.7%), nausea (27.7%), fatigue (20.3%), decreased appetite (19.2%), anemia (17.5%), constipation (16.4%), diarrhea (14.7%), headache (13.0%), neutropenia (12.4%), and peripheral edema (10.7%). In the subset (n = 95) of TAMARACK pts on treatment for ≥ 12 weeks or who discontinued study treatment within 12 weeks, TEAEs led to drug interruption in 12 (12.6%) and discontinuation in 5 (5.3%) pts. This compares favorably to the rate of drug interruption (58.5%) and discontinuation (14.6%) observed at 12 weeks in pts with mCRPC who received vobra duo at 3.0 mg/kg Q3W on the Phase 1 study. Following the pre-specified interim analysis for futility on both arms, the IDMC recommended continuing the study as planned without modification. Conclusions Preliminary safety data from TAMARACK suggest that reducing the dose and frequency of vobra duo improves its safety and tolerability in men with mCRPC. The authors anticipate sharing preliminary efficacy data and updated safety data at the conference. Clinical trial information: NCT05551117.” MacroGenics would like to thank the abstract authors, including: Johann S. De Bono, Carole Helissey, Karim Fizazi, Eric Voog, Pablo Maroto-Rey, Guilhem Roubaud, Emmanuel S. Antonarakis, Shahneen Sandhu, Neal D. Shore, Raffaele Ratta, Begoña Pérez Valderrama, Christof Vulsteke, Galina Marr, Ashley Ward, Enxu Zhao, Josep M. Piulats, on behalf of the TAMARACK Investigators. About MacroGenics, Inc. MacroGenics (the Company) is a biopharmaceutical company focused on discovering, developing, manufacturing and commercializing innovative monoclonal antibody-based therapeutics for the treatment of cancer. The Company generates its pipeline of product candidates primarily from its proprietary suite of next-generation antibody-based technology platforms, which have applicability across broad therapeutic domains. The combination of MacroGenics' technology platforms and protein engineering expertise has allowed the Company to generate promising product candidates and enter into several strategic collaborations with global pharmaceutical and biotechnology companies. For more information, please see the Company's website at . MacroGenics and the MacroGenics logo are trademarks or registered trademarks of MacroGenics, Inc. Cautionary Note on Forward-Looking Statements Any statements in this press release about future expectations, plans and prospects for MacroGenics (“Company”), including statements about the Company’s strategy, future operations, clinical development of the Company’s therapeutic candidates, including initiation and enrollment in clinical trials, expected timing of results from clinical trials, discussions with regulatory agencies, commercial prospects of or product revenues from MARGENZA and the Company’s product candidates, if approved, manufacturing services revenue, milestone or opt-in payments from the Company’s collaborators, the Company’s anticipated milestones and future expectations and plans and prospects for the Company, as well as future global net sales of TZIELD and the Company’s ability to achieve the milestone payments set forth under the terms of the agreement with DRI (or its successors or assigns with respect to such agreement), and other statements containing the words “subject to”, "believe", “anticipate”, “plan”, “expect”, “intend”, “estimate”, “potential,” “project”, “may”, “will”, “should”, “would”, “could”, “can”, the negatives thereof, variations thereon and similar expressions, or by discussions of strategy constitute forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including: risks that TZIELD, vobramitamab duocarmazine, lorigerlimab, ZYNYZ, MARGENZA or any other product candidate’s revenue, expenses and costs may not be as expected, risks relating to TZIELD, vobramitamab duocarmazine, lorigerlimab, ZYNYZ, MARGENZA or any other product candidate’s market acceptance, competition, reimbursement and regulatory actions; our ability to provide manufacturing services to our customers; the uncertainties inherent in the initiation and enrollment of future clinical trials; the availability of financing to fund the internal development of our product candidates; expectations of expanding ongoing clinical trials; availability and timing of data from ongoing clinical trials; expectations for the timing and steps required in the regulatory review process; expectations for regulatory approvals; expectations of future milestone payments; the impact of competitive products; our ability to enter into agreements with strategic partners and other matters that could affect the availability or commercial potential of the Company's product candidates; business, economic or political disruptions due to catastrophes or other events, including natural disasters, terrorist attacks, civil unrest and actual or threatened armed conflict, or public health crises such as the novel coronavirus (referred to as COVID-19 pandemic); and other risks described in the Company's filings with the Securities and Exchange Commission. In addition, the forward-looking statements included in this press release represent the Company's views only as of the date hereof. The Company anticipates that subsequent events and developments will cause the Company's views to change. However, while the Company may elect to update these forward-looking statements at some point in the future, the Company specifically disclaims any obligation to do so, except as may be required by law. These forward-looking statements should not be relied upon as representing the Company's views as of any date subsequent to the date hereof. CONTACTS: Jim Karrels, Senior Vice President, CFO 1-301-251-5172 info@macrogenics.com