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BriaCell Abstracts Showcase Positive Survival and Clinical Benefit Data at ASCO 2025

On May 23, 2025 BriaCell Therapeutics Corp. (Nasdaq: BCTX, BCTXW, BCTXZ), (TSX: BCT) (" BriaCell " or the " Company "), a clinical-stage biotechnology company developing novel immunotherapies to transform cancer care, reported the presentation of positive survival and clinical benefit data in three clinical poster presentations and one publish-only abstract at the upcoming 2025 American Society of Clinical Oncology (ASCO) (Free ASCO Whitepaper) Annual Meeting taking place May 30 – June 3 at McCormick Place, Chicago, IL (Press release, BriaCell Therapeutics, MAY 23, 2025, View Source [SID1234653598]).

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"We are highly encouraged by the survival and clinical benefit data from our Phase 2 Bria-IMT study which meets and outperforms outcomes seen with FDA approved therapies – despite our patients being more heavily pre-treated," stated Dr. William V. Williams, BriaCell’s President & CEO. "These results reinforce our belief in Bria-IMT’s potential to address the urgent, unmet needs of patients with metastatic breast cancer and we look forward to confirming results in our ongoing pivotal Phase 3 study."

"These data provide additional validation of the mechanism of action and support the clinical efficacy of Bria-IMT," noted Giuseppe Del Priore, MD, MPH, BriaCell’s Chief Medical Officer. "Importantly, the regimen has been well-tolerated and its favorable safety and efficacy profile positions it as a promising, less toxic therapeutic option for patients battling metastatic breast cancer."

The details of the poster presentation sessions and publish-only abstract are listed below.

Abstract Title: Update on phase III pivotal trial of Bria-IMT + CPI vs physician’s choice in advanced metastatic breast cancer (BRIA-ABC)
Session Date and Time: June 2, 2025 9:00 AM-12:00 PM CDT
Abstract Number for Publication: TPS1138
Poster Board Number: 108a
Session Type and Title: Poster Session – Breast Cancer—Metastatic

Preliminary selected clinical and biomarker data from BriaCell’s ongoing pivotal Phase 3 study of Bria-IMT plus an immune checkpoint inhibitor (CPI) in metastatic breast cancer ( NCT06072612 ).

Abstract Title: Bria-IMT + checkpoint inhibitor: Phase I/II survival results compared to benchmark trials in metastatic breast cancer
Session Date and Time: June 2, 2025 9:00 AM-12:00 PM CDT
Abstract Number for Publication: 1096
Poster Board Number: 75
Session Type and Title: Poster Session – Breast Cancer—Metastatic

Phase 2 study of Bria-IMT in combination immunotherapy with an immune checkpoint inhibitor (CPI) consisted of 54 patients; 11 received pembrolizumab, 44 retifanlimab (1crossover).

Table 1: Median overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and clinical benefit rate (CBR) were evaluated against two pivotal Phase 3 studies of FDA approved drugs, ASCENT (Trodelvy (SG) or Treatment of Physicians Choice (TPC) in triple-negative breast cancer (TNBC)) and TROPiCS-02 (SG or TPC in Hormone Receptor +/HER2- MBC)
Trial (Cohort) Age (median, range) Prior Therapies (median, range) OS (months) PFS (months) ORR
(%) CBR
(%)
Bria-IMT (Overall Cohort) 61 (38-81) 6 (2-13) 9.9 (1.8-30.3) 3.6 10% 55%
Bria-IMT (Phase 3 regimen) 62 (44-80) 6 (2-13) 13.43 (1.8-30.3) 3.6 (1.8-16.5) 14 % 61 %
ASCENT (SG) 54 (27-82) 4 (2-17) 11.8 4.8 31% 40%
ASCENT (TPC) 53 (27-81) 4 (2-14) 6.9 1.7 4% 8%
TROPiCS-02 (SG) 57 (49-65) 3 14.4 5.5 21% 34%
TROPiCS-02 (TPC) 55 (48-63) 3 11.2 4 14% 22%
Bria-IMT was well-tolerated with no treatment-related discontinuations. 22% of patients are still in active survival follow up.

This analysis does not stratify Bria-IMT patients by hormone receptor or HER2 status, and the dataset reflects the information available at the time of abstract submission. Updated data will be shared during the company’s presentation at ASCO (Free ASCO Whitepaper) 2025.

PFS (median) and OS (median): Patients treated with Bria-IMT’s selected Phase 3 formulation (without IFNγ; N = 37) demonstrated significantly improved progression-free survival (3.6 vs. 2.6 months; P = 0.01) and overall survival (13.4 vs. 6.9 months; P = 0.01) compared to those who received the alternate formulation not advanced to Phase 3.

The overall survival observed in the Phase 3 formulation cohort (13.4 months) was comparable to that reported in the ASCENT (11.8 months) and TROPiCS-02 (14.4 months) studies and exceeded survival outcomes in their respective treatment of physician’s choice (TPC) arms (6.9 and 11.2 months).

BriaCell’s Phase 2 study also achieved a Clinical Benefit Rate (CBR) of 61%, outperforming ASCENT (40%) and TROPiCS-02 (34%), and an Objective Response Rate (ORR) of 14%, which matched or exceeded the TPC arms in both studies (4% and 14%).

Importantly, these outcomes were achieved in a more heavily pretreated patient population than those in the comparator trials—highlighting Bria-IMT’s strong anti-cancer activity. The favorable efficacy profile of the Phase 3 formulation supports its continued evaluation in BriaCell’s ongoing pivotal Phase 3 trial comparing Bria-IMT to treatment of physician’s choice ( NCT06072612 ).

Abstract Title: Trial in progress: A study of Bria-OTS cellular immunotherapy in metastatic recurrent breast cancer
Session Date and Time: June 2, 2025 9:00 AM-12:00 PM CDT
Abstract Number for Publication: TPS1136
Poster Board Number: 107a
Session Type and Title: Poster Session – Breast Cancer—Metastatic

Heavily pre-treated MBC patients were treated in a dose escalation Phase 1/2 study of Bria-OTS monotherapy (single agent). The Phase 1 part of the study has enrolled and treated 3 patients. The first patient treated with single agent therapy has confirmed resolution of a breast cancer metastasis in the lung and remains on study.

Publish-Only Abstract Title : Impact of HLA Matching on Clinical Outcomes in a Phase 2 Trial of Bria-IMT Plus Anti PD1 in Advanced Breast Cancer

Following the presentations, copies of the presentations will be posted on View Source

IMUNON Announces Up To $9.75 Million Private Placement Priced At-The-Market Under Nasdaq Rules

On May 23, 2025 IMUNON, Inc. (NASDAQ: IMNN), a clinical-stage company in Phase 3 development of its DNA-mediated immunotherapy, reported that it has entered into definitive agreements for the issuance and sale of an aggregate of 7,222,223 shares of its common stock (or pre-funded warrants in lieu therof) and short-term warrants to purchase up to an aggregate of 14,444,446 shares of common stock at a purchase price of $0.45 per share (or pre-funded warrant in lieu thereof) and accompanying short-term warrants in a private placement priced at-the-market under Nasdaq rules (Press release, IMUNON, MAY 23, 2025, View Source [SID1234653374]). The warrants will be exercisable beginning on the effective date of stockholder approval of the issuance of the shares of common stock upon exercise of the warrants at an exercise price of $0.45 per share and will expire three years from the date of stockholder approval. The offering is expected to close on or about May 27, 2025, subject to the satisfaction of customary closing conditions.

H.C. Wainwright & Co. is acting as the the exclusive placement agent for the offering. Brookline Capital Markets, a division of Arcadia Securities, LLC, is acting as financial advisor.

The aggregate gross proceeds to the Company from the private placement is expected to be approximately $3.25 million, before deducting placement agent fees and other offering expenses payable by the Company. The potential additional gross proceeds to the Company from the short-term warrants, if fully-exercised on a cash basis, will be approximately $6.5 million. No assurance can be given that any of such short-term warrants will be exercised. The Company intends to use the net proceeds from the offering for working capital and general corporate purposes.

The shares of common stock, pre-funded warrants and short-term warrants described above were offered in a private placement under Section 4(a)(2) of the Securities Act of 1933, as amended (the "Act") and Regulation D promulgated thereunder and, along with the shares of common stock underlying the pre-funded warrants and short-term warrants, have not been registered under the Act or applicable state securities laws. Accordingly, the shares of common stock, the pre-funded warrants, the short-term warrants and the shares of common stock underlying the pre-funded warrants and short-term warrants may not be offered or sold in the United States absent registration with the Securities and Exchange Commission ("SEC") or an applicable exemption from such registration requirements. The securities were offered only to accredited investors. Pursuant to a registration rights agreement, the Company has agreed to file one or more registration statements with the SEC covering the resale of the shares of common stock and the shares issuable upon exercise of the pre-funded warrants and short-term warrants.

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 state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

Antengene to Present Latest Clinical Results from Two Studies in CPI-resistant Solid Tumors at ASCO 2025

On May 23, 2025 Antengene Corporation Limited ("Antengene", SEHK: 6996.HK), a leading innovative, commercial-stage global biopharmaceutical company dedicated to discovering, developing and commercializing first-in-class and/or best-in-class medicines for hematologic malignancies and solid tumors, reported that it will present the latest clinical data of its CD73 oral small molecule inhibitor ATG-037 and oral dual mTORC1/2 inhibitor ATG-008 in Poster Presentations at the 2025 American Society of Clinical Oncology (ASCO) (Free ASCO Whitepaper) Annual Meeting, taking place from May 30th to June 3rd in Chicago, IL, the United States (Press release, Antengene, MAY 23, 2025, View Source [SID1234653373]).

Details of the Poster Presentations:
ATG-037 (CD73 Small Molecule Inhibitor)
Title: A First-In-Human Phase I/Ib study of ATG-037 Monotherapy and Combination Therapy with Pembrolizumab in Patients with Advanced Solid Tumors – STAMINA-01
Abstract: 3123
Session: Developmental Therapeutics—Molecularly Targeted Agents and Tumor Biology
Date: June 2, 2025
Time: 1:30 PM – 4:30 PM (Central Time)
2:30 AM – 5:30 AM, June 3, 2025 (Beijing Time)

Robust clinical benefit observed in CPI-resistant patients: As of April 27, 2025, the study has already completed the dose escalation part in which 43 patients were enrolled and received monotherapy. Among them, 28 CPI-resistant patients also received the combination therapy. Among patients treated with the combination therapy, 6 patients (4 melanoma and 2 NSCLC patients) achieved a confirmed PR with an ORR of 21.4%, and 16 patients achieved stable disease (SD) with a DCR of 78.6%. The combination regimen delivered particularly encouraging efficacy in melanoma, with all 11 CPI-resistant patients achieving disease control (DCR 100%) and an ORR of 36.4% (4 PRs), including 1 patient having maintained PR and remained in the study for over 2 years without any safety concerns. In CPI-resistant NSCLC, the combination regimen achieved an ORR of 22% (PRs) and a DCR of 67%. These results highlight the potential of ATG-037 to deliver meaningful clinical benefit across multiple tumor types, reinforcing its promise as a novel treatment option in CPI-resistant cancers.
Manageable safety profile: Treatment-related adverse events were reported in 56% (24/43) of patients receiving monotherapy and 61% (17/28) of patients receiving the combination therapy. The majority of these TRAEs were grade 1-2. Only one serious TRAE (grade 3 immune mediated hepatitis) was observed in the study.
Two key differentiators: ATG-037 is an oral small molecule CD73 inhibitor offering greater convenience over intravenous (IV) injectable agents and is uniquely designed to overcome the ‘hook effect’ commonly seen in anti-CD73 antibodies, enabling complete and more effective CD73 inhibition.
The STAMINA-01 trial: STAMINA-01 is a Phase I/Ib study jointly conducted by Antengene and MSD (Merck & Co., Inc., Rahway, NJ, USA). The study was designed to evaluate the safety, pharmacokinetics, and optimal dosing of ATG-037 as a monotherapy and in combination with MSD’s anti-PD-1 therapy, KEYTRUDA (pembrolizumab), in patients with refractory/relapsed solid tumors. At present, dose optimization and dose expansion parts of the study are being carried out as planned in China and Australia.
KEYTRUDA is a registered trademark of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.

ATG-008 (mTORC1/2 Small Molecule Inhibitor)
Title: A TORC1/2 inhibitor onatasertib combined with toripalimab in patients with advanced cervical cancers with prior anti-PD-(L)1 therapy
Abstract: 5540
Session: Gynecologic Cancer
Date: June 1, 2025
Time: 9:00 AM – 12:00 PM (Central Time)
10:00 PM, June 1, 2025 – 1:00 AM, June 2, 2025 (Beijing Time)

The TORCH-2 trial: ATG-008 is an oral dual mTOR1/2 inhibitor. The TORCH-2 trial is a Phase I/II dose escalation and dose expansion study of ATG-008 in combination with the anti-PD-1 monoclonal antibody toripalimab in patients with advanced solid tumors. This abstract reports data from patients with advanced cervical cancer who had previously received at least prior 1 line of anti-PD-(L)1 therapy and 1 line of platinum chemotherapy, regardless of the PD-L1 expression. As of November 25, 2024, 30 qualified patients were enrolled and received ATG-008 15 mg orally once a day (QD) in combination with toripalimab 240 mg, once every 21 days (Q3W). Among them, 14 and 16 patients had received 1 and at least 2 prior lines of systemic therapy, respectively. The median time since initial diagnosis was 37 months.
Encouraging efficacy in patients with CPI-resistant cervical cancer: Among 27 efficacy-evaluable patients, the combination regimen achieved an ORR of 22.2% and a DCR of 85.2%. The ORRs of PD-L1 positive and PD-L1 negative populations were 30% (3/10) and 33.3% (2/6), respectively. The median time to response was 1.7 months (1.4, 4.2) and the median duration of response (DOR) was 5.7 months (95% CI: 2.7, NE). The median progression-free survival (PFS) was 4.2 months (95% CI: 3.3, 5.8) and the median overall survival (OS) was 21.4 months (95% CI: 15.5, NE). These results underscore the potential of ATG-008 in combination with toripalimab in providing meaningful clinical benefit for CPI-resistant cervical cancer patients, reinforcing its promise as a novel treatment option for this difficult-to-treat patient population.
Manageable safety profile: All 30 patients experienced at least one TEAE, and 22 patients (73.3%) reported grade ≥3 TRAEs. The most common all-grade TRAEs were hyperglycaemia (56.7%), rash (43.3%) and white blood cell decreased (43.3%). Most TRAEs were grade 1-2, and no TEAE led to death.

Nona Biosciences Collaboration Partner Pfizer Announces Presentation of Phase 1 Clinical Study Design on MesoC2, an MSLN-Targeting ADC, at the 2025 ASCO Annual Meeting

On May 23, 2025 Nona Biosciences, a global biotechnology company providing integrated solutions from "Idea to IND" (I to ITM), reported that its collaborator, Pfizer, will present an abstract detailing the first-in-human Phase 1 clinical study design of MesoC2 (HBM9033/PF-08052666), a first-in-class mesothelin (MSLN)-targeting antibody-drug conjugate (ADC), at the 2025 American Society of Clinical Oncology (ASCO) (Free ASCO Whitepaper) Annual Meeting (Press release, Nona Biosciences, MAY 23, 2025, View Source [SID1234653372]).

MesoC2, originally developed using Nona’s proprietary Harbour Mice and integrated ADC platforms, was licensed to Pfizer in December 2023 under a global rights agreement. Pfizer is currently evaluating the ADC in a Phase 1, open-label study in patients with advanced solid tumors, including mesothelioma, platinum-resistant ovarian cancer (PROC), pancreatic ductal adenocarcinoma (PDAC), non-small cell lung cancer (NSCLC), endometrial cancer (EC), and colorectal cancer (CRC).

Poster Presentation at the 2025 ASCO (Free ASCO Whitepaper) Annual Meeting
Title: A phase 1 study to evaluate the safety and tolerability of the antibody–drug conjugate (ADC) MesoC2 (PF-08052666) in patients with advanced solid tumors
Abstract Number: TPS3163
Poster Board Number: 475a
Session Title: Poster Session – Developmental Therapeutics – Molecularly Targeted Agents and Tumor Biology
Session Date and Time: 02 June 2025; 1:30 PM-4:30 PM (CDT)

Key Highlights from the Presentation:

MesoC2 is an ADC composed of a human IgG1 anti-MSLN monoclonal antibody conjugated to a cleavable tripeptide linker carrying a topoisomerase 1 inhibitor (TOP1i) payload (average drug-to-antibody ratio of 8).
MesoC2 has shown potent antitumor efficacy in in vitro assays and xenograft models and an acceptable safety profile in cynomolgus monkeys.
The Phase 1 trial (NCT06466187) will assess the safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary efficacy per RECIST v1.1 criteria of MesoC2 in up to 365 patients across dose escalation, optimization, and expansion cohorts.
"We are excited to see Pfizer advancing MesoC2 into clinical development rapidly, highlighting the potential of Nona’s Harbour Mice and integrated ADC platforms to deliver innovative cancer therapies," said Dr. Jingsong Wang, Chairman of Nona Biosciences. "The initiation of this Phase 1 trial marks a significant milestone in our collaboration and underscores our shared commitment to addressing unmet needs in oncology."

Pfizer’s presentation at the 2025 ASCO (Free ASCO Whitepaper) Annual Meeting will provide further insights into the trial design. Additional details on the study can be found at ClinicalTrials.gov (NCT06466187).

About MesoC2 (HBM9033/PF-08052666)

MesoC2 (HBM9033/PF-08052666) is an ADC drug that targets human MSLN, a tumor-associated antigen (TAA) upregulated in various solid tumors. The fully human monoclonal antibody (mAb) in MesoC2 is derived from the Harbour Mice platform and possesses well-tuned properties, exhibiting reduced binding to soluble MSLN while maintaining strong binding and internalization to membrane-bound MSLN. The unique design of the mAb was created to enhance potency in various preclinical tumor models with differing MSLN expression levels, positioning MesoC2 as a potential globally best-in-class therapeutic option.

Six Abstracts of Kelun-Biotech’s Clinical Studies Published at the 2025 ASCO Annual Meeting

On May 23, 2025 Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. (6990.HK, the "Company") reported it will present results from six clinical studies, including data on its TROP2 ADC sac-TMT, anti-PD-L1 mAb tagitanlimab, and RET inhibitor KL590586 (A400/EP0031) at the 2025 American Society of Clinical Oncology (ASCO) (Free ASCO Whitepaper) Annual Meeting scheduled to take place in Chicago, Illinois, USA from May 30 to June 3 (Press release, Kelun, MAY 23, 2025, View Source [SID1234653371]).

The study abstracts were published on the ASCO (Free ASCO Whitepaper) website on May 22, 2025 (CDT), with key highlights summarized below:

1. Sac-TMT in patients with previously treated advanced epidermal growth factor receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC): Results from the randomized OptiTROP-Lung03 study

Oral Presentation: June 1, 10:12-10:24 CDT (Abstract #8507: Lung Cancer – Non-Small Cell Metastatic)

A total of 137 patients with advanced EGFR-mutant NSCLC who had progressed after EGFR-tyrosine kinase inhibitor (TKI) and platinum-based chemotherapy were randomized (2:1) to receive sac-TMT (5 mg/kg once every 2 weeks (Q2W)) or docetaxel (75 mg/m2 once every 3 weeks (Q3W)). The median follow-up of 12.2 months (data cutoff: December 31, 2024).

Sac-TMT achieved statistically significant and clinically meaningful outcomes compare d to docetaxel: confirmed objective response rate (ORR) (blinded independent review committee (BIRC): 45.1% vs 15.6%, one-sided p=0.0004), progression-free survival (PFS) (BIRC: median 6.9 vs 2.8 months, hazard ratio (HR)= 0.30, one-sided p<0.0001; investigator (INV): median 7.9 vs 2.8 months, HR=0.23). With 36.4% of patients in docetaxel group crossing over to receive sac-TMT, median overall survival (OS) was not reached (NR) for both groups (HR 0.49, one-sided p=0.007). The median OS analysed by pre-specified rank-preserving structural failure time (RPSFT) model adjusted for crossover was 9.3 months for docetaxel and NR for sac-TMT (HR=0.36).

Grade ≥ 3 treatment-related adverse events (TRAEs) occurred in 56.0% of patients in sac-TMT group vs 71.7% in docetaxel group. No cases of interstitial lung disease (ILD) were reported in sac-TMT group.

These results led to the approval of sac-TMT in EGFR mutation-positive locally advanced or metastatic non-squamous NSCLC following progression on EGFR-TKI therapy and platinum-based chemotherapy in China, which marks the first approval for a TROP2 ADC in lung cancer globally.

2. Sac-TMT as first-line treatment for unresectable locally advanced/metastatic triple-negative breast cancer (a/m TNBC): Initial results from the Phase 2 OptiTROP-Breast05 study

Rapid Oral Presentation: May 30, 15:45-15:51 CDT (Abstract #1019: Breast Cancer – Metastatic)

As of November 18, 2024, a total of 41 patients with a/m TNBC who had not received prior treatment for advanced disease (median age 55 years; 43.9% Eastern Cooperative Oncology Group (ECOG) Performance status (PS) 1; 78.0% PD-L1 combined positive score (CPS)<10) were enrolled to receive sac-TMT monotherapy at 5 mg/kg Q2W until disease progression or unacceptable toxicity. The median follow-up was 18.6 months.

The ORR was 70.7% and the disease control rate (DCR) was 92.7%. Median duration of response (DoR) was 12.2 months, while the median PFS was 13.4 months. Among the 32 patients with PD-L1 CPS <10, the ORR was 71.9% and the DCR was 93.8%. The median PFS in this subgroup was 13.1 months.

TRAEs of grade 3 or higher occurred in 63.4% of patients. No treatment-related deaths occurred, and there were no reports of neuropathy or ILD/pneumonitis.

3. Sac-TMT in combination with tagitanlimab (anti-PD-L1) in first-line (1L) advanced NSCLC: Non-squamous cohort from the Phase 2 OptiTROP-Lung01 study

Poster Presentation: May 31, 13:30-16:30 CDT (Abstract #8529: Lung Cancer – Non-Small Cell Metastatic)

Advanced NSCLC patients with no prior systemic therapy and no actionable genomic alterations were enrolled to receive sac-TMT (5 mg/kg Q3W or Q2W) plus tagitanlimab (1,200 mg Q3W or 900 mg Q2W) until disease progression or unacceptable toxicity. As of December 30, 2024, 81 patients with non-squamous histology were enrolled.

After median follow-up of 17.1 months, confirmed ORR was 59.3%; Median DoR was 16.5 months; Median PFS was 15.0 months. Among patients with PD-L1 tumor proportion score (TPS)≥50%, the confirmed ORR was 77.8%; median PFS was 17.8 months; while for patients with PD-L1 TPS≥1%, the confirmed ORR was 68.1%; median PFS was 17.8 months. Among patients with PD-L1 TPS< 1%, confirmed ORR was 47.1%; median PFS was 12.4 months. Most common Grade≥3 TRAEs were neutrophil count decreased (45.7%), anemia (16.0%), white blood cell count decreased (14.8%) and stomatitis (11.1%). No TRAE led to treatment discontinuation or death.

4. Sac-TMT in patients with previously treated locally advanced or metastatic (LA/M) NSCLC harboring uncommon EGFR mutations: Preliminary results from a Phase 2 Study

Poster Presentation: May 31, 13:30-16:30 CDT (Abstract #8615: Lung Cancer – Non-Small Cell Metastatic)

As of December 1, 2024, 42 advanced NSCLC patients who had progressed on or after systemic therapy were enrolled, including 23 patients with EGFR G719X in exon 18, S768I in exon 20, or L861Q in exon 21 and 19 patients with EGFR ex20ins. Patients received sac-TMT 5 mg/kg Q2W until disease progression or unacceptable toxicity.

After a median follow-up of 9.2 months, the ORR was 35.7% and the DCR was 85.7%. Responses were durable with the median DoR not yet reached. The median PFS was 9.5 months. In the subset of patients with uncommon non-ex20ins, the ORR was 34.8%; the median PFS was 10.9 months. In the subset of patients with ex20ins, the ORR was 36.8% and the median PFS was 9.0 months.

Grade ≥3 TRAEs occurred in 52.4% of patients. No TRAEs led to treatment discontinuation or death. No cases of ILD/pneumonitis were reported.

5. Tagitanlimab versus placebo in combination with gemcitabine and cisplatin (GP) as first-line treatment for recurrent or metastatic nasopharyngeal carcinoma (R/M NPC): Results from a randomized, double-blind, phase Phase 3 study

Oral Presentation: May 31, 14:27-14:39 CDT (Abstract #6004: Head and Neck Cancer).

Eligible R/M NPC patients who have not previously received systemic therapy were in 2:1 ratio randomly assigned to receive tagitanlimab or placebo (1200 mg, D1) in combination with cisplatin (80 mg/m2, D1) and gemcitabine (1000 mg/m2, D1 and D8) Q3W for up to 6 cycles followed by tagitanlimab or placebo monotherapy Q3W until disease progression, unacceptable toxicity, or withdrawal of consent. The median follow-up time was 11.7 months.

The PFS per blinded independent central review (BICR) was met with a 53% reduction in risk of progression or death (HR=0.47, one-sided P <0.0001). The median PFS was not reached in tagitanlimab plus GP arm and 7.9 months in placebo plus GP arm. The ORR per BICR was 81.7% in tagitanlimab plus GP arm and 74.5% in placebo plus GP arm, with a median DoR of 11.7 months and 5.8 months (HR=0.48), respectively. The OS benefit was observed in tagitanlimab plus GP arm vs placebo plus GP arm (median OS not reached for either arm; HR=0.62). Tagitanlimab also showed a manageable safety profile.

6. Results from a Phase 1 study of KL590586 in patients with advanced RET-mutant medullary thyroid cancer (MTC)

Poster Presentation: June 2, 9:00-12:00 CDT (Abstract #6098: Head and Neck Cancer)

As of September 20, 2024, 27 advanced RET-mutant MTC patients without prior selective RET inhibitors were enrolled and treated in the phase 1 part across 4 dose levels (20 to 90 mg once a day (QD)). The median follow-up was 19.0 months.

As of September 20, 2024, the confirmed ORR was 63.0% and the DCR was 100% for overall population. The confirmed ORR was 56.3% (9/16) and 62.5% (5/8) in patients with prior multikinase inhibitor (MKI) or treatment naïve, respectively. Median DoR was not reached, with the longest duration still ongoing at 25.8 months. Similarly, median PFS was not reached, with the 24-month PFS rate of 77.8%.

All patients experienced TRAEs, with grade ≥3 TRAEs occurred in 22.2% of patients. No TRAEs led to treatment discontinuation or death.

About sac-TMT

Sac-TMT, a core product of the Company, is a novel human TROP2 ADC in which the Company has proprietary intellectual property rights, targeting advanced solid tumors such as NSCLC, breast cancer (BC), gastric cancer (GC), gynecological tumors, among others. Sac-TMT is developed with a novel linker to conjugate the payload, a belotecan-derivative topoisomerase I inhibitor with a drug-to-antibody-ratio (DAR) of 7.4. Sac-TMT specifically recognizes TROP2 on the surface of tumor cells by recombinant anti-TROP2 humanized monoclonal antibodies, which is then endocytosed by tumor cells and releases KL610023 intracellularly. KL610023, as a topoisomerase I inhibitor, induces DNA damage to tumor cells, which in turn leads to cell-cycle arrest and apoptosis. In addition, it also releases KL610023 in the tumor microenvironment. Given that KL610023 is membrane permeable, it can enable a bystander effect, or in other words kill adjacent tumor cells.

In May 2022, the Company licensed the exclusive rights to MSD (the tradename of Merck & Co., Inc, Rahway, NJ, USA) to develop, use, manufacture and commercialize sac-TMT in all territories outside of Greater China (which includes Mainland China, Hong Kong, Macao and Taiwan).

To date, two indications for sac-TMT have been approved and marketed in China for the treatment of adult patients with unresectable locally advanced or metastatic TNBC who have received at least two prior systemic therapies (at least one of them for advanced or metastatic setting) and EGFR mutation-positive locally advanced or metastatic non-squamous NSCLC following progression on EGFR-TKI therapy and platinum-based chemotherapy. Sac-TMT became the first domestically developed and fully approved for marketing ADC in China with global intellectual property rights. It is also the world’s first TROP2 ADC to be approved for marketing in a lung cancer indication. In addition, two new indication applications for sac-TMT for the treatment of adult patients with EGFR-mutant locally advanced or metastatic NSCLC who progressed after treatment with EGFR-TKI therapy and with unresectable locally advanced, metastatic hormone receptor-positive (HR+) and human epidermal growth factor receptor 2-negative (HER2-) BC who have received prior endocrine therapy and other systemic treatments in the advanced or metastatic setting were accepted by the National Medical Products Administration (NMPA), and were (to be) reviewed via the priority review and approval process. As of today, the Company has initiated 8 registrational clinical studies in China. MSD has initiated 14 ongoing Phase 3 global clinical studies of sac-TMT as a monotherapy or with pembrolizumab[1] or other agents for several types of cancer. These studies are sponsored and led by MSD.

About Tagitanlimab

Tagitanlimab is the first PD-L1 mAb to receive authorization for the first-line treatment of NPC. Previously, the NMPA has approved the marketing in China of tagitanlimab used in combination with cisplatin and gemcitabine for the first-line treatment of patients with R/M NPC and monotherapy for the treatment of patients with recurrent or metastatic NPC who have failed after prior 2L+ chemotherapy, respectively.

About KL590586 (A400/EP0031)

KL590586(A400/EP0031) is a novel next-generation selective RET inhibitor for NSCLC, MTC and other solid tumors with a high prevalence of RET alterations. The Company are currently conducting pivotal clinical studies for both 1L and 2L+ advanced RET+ NSCLC as well as a phase 1b/2 clinical study for RET+ MTC and solid tumor in China.

In March 2021, The Company granted Ellipses Pharma Limited, a U.K.-based international oncology drug development company, an exclusive license to develop, manufacture and commercialize this agent outside Greater China and certain Asian countries under the code EP0031.

In March 2024, it was announced that EP0031/A400 was granted Fast Track designation by the Food and Drug Administration (FDA) for the treatment of RET-fusion positive NSCLC. In April 2024, EP0031/A400 was cleared by the FDA to progress into Phase 2 clinical development and is now open in the US, UK, EU and UAE.