Targeting CTLA-4 Research Articles

Combined PD-1 and CTLA-4 Blockade in an International Cohort of Patients with Acral Lentiginous Melanoma.

Combination immune checkpoint blockade targeting PD-1 and CTLA-4 leads to high response rates and improved survival in advanced cutaneous melanoma (CM). Less is known about the efficacy of this combination in acral lentiginous melanoma (ALM). To determine the efficacy of combination immune checkpoint blockade targeting PD-1 and CTLA-4 in a real-world, diverse population of ALM. This multi-institutional retrospective study analyzed patients with histologically confirmed ALM treated with the combination of PD-1 and CTLA-4 inhibitors between 2010-2022. The primary objective of the study was objective response rate (ORR) per RECIST criteria. The secondary objectives were progression-free survival (PFS) and overall survival (OS). In total, 109 patients with advanced ALM treated with combined PD-1 and CTLA-4 blockade in any line of treatment were included. The majority of patients had stage IV disease (n=81, 74.2%). The ORR for the entire cohort was 18.3% (95% CI 11.6-26.9%), with 9 (8.3%) complete responses (CR) and 11 (10.1%) partial responses (PR). An additional 22 patients (20.2%) had stable disease (SD), and the disease control rate (DCR) was 38.5%. The median PFS was 4.2 months [95% CI 3.25-5.62], while the median OS was 17 months [95% CI 12.4%-23.1%]. A total of 95 patients (87.2%) had a treatment-related adverse event, with 40.4% (n=44/109) experiencing at least one grade 3 or 4 toxicity. Elevated LDH (p=.04), 2+ lines of prior therapy (p=.03), and Asian race/ethnicity (p=.04) were associated with worse OS, while Hispanic/Latino race/ethnicity was associated with better OS (p=.02). Combination of PD-1 and CTLA-4 blockade is less effective for ALM, as compared to CM, despite similar toxicity. Asian patients, in particular, appear to derive lower benefit from this regimen. Novel treatment approaches are needed for this rare melanoma subtype.

A novel anti-CTLA-4 nanobody-IL12 fusion protein in combination with a dendritic cell/tumour fusion cell vaccine enhances the antitumour activity of CD8+ T cells in solid tumours.

We previously developed a nanobody targeting CTLA-4 and demonstrated that it can boost antitumour T-cell responses in vitro; however, the resulting responses after the injection of T cells into cancer models are usually weak and transient. Here, we explored whether fusing our nanobody to IL-12 would enable it to induce stronger, longer-lasting T-cell immune responses after exposure to immature dendritic cell and tumour cell fusions. The fusion protein enhanced the response of CD8+ T cells to tumour antigens in vitro and led to stronger, more persistent immune responses after the T cells were injected into mice bearing different types of xenografts. Our in vitro and in vivo results suggest the anticancer potential of our nanobody-interleukin fusion system and support the clinical application of this fusion approach for various nanobodies.

Cadonilimab plus platinum-based chemotherapy with or without bevacizumab as first-line treatment for persistent, recurrent, or metastatic cervical cancer (COMPASSION-16): a randomised, double-blind, placebo-controlled phase 3 trial in China

Cadonilimab is a bispecific antibody targeting PD-1 and CTLA-4, which has shown substantial clinical benefits in advanced cervical cancer. In the COMPASSION-16 trial, we aimed to evaluate the addition of cadonilimab to first-line standard chemotherapy in persistent, recurrent, or metastatic cervical cancer. In this randomised, double-blind, multicentre, placebo-controlled phase 3 trial, women aged 18-75 years across 59 clinical sites in China with previously untreated persistent, recurrent, or metastatic cervical cancer were randomly assigned (1:1) to receive cadonilimab (10 mg/kg) or placebo plus platinum-based chemotherapy with or without bevacizumab every 3 weeks for six cycles, followed by maintenance therapy every 3 weeks for up to 2 years. Randomisation was performed centrally through an interactive web-response system. Stratification factors were the use of bevacizumab (yes or no) and previous concurrent chemoradiotherapy (yes or no). The dual primary outcomes were progression-free survival as assessed by blinded independent central review and overall survival in the full analysis set. This study is registered with ClinicalTrials.gov, NCT04982237; the study has completed enrolment and is ongoing for treatment and follow-up. 445 eligible women were enrolled between Sept 11, 2021, and June 23, 2022. Median progression-free survival was 12·7 months (95% CI 11·6-16·1) in the cadonilimab group and 8·1 months (7·7-9·6) in the placebo group (hazard ratio 0·62 [95% CI 0·49-0·80], p<0·0001); median overall survival was not reached (27·0 months to not estimable) versus 22·8 months (17·6-29·0), respectively (hazard ratio 0·64 [0·48-0·86], p=0·0011). The most common grade 3 or higher adverse events were decreased neutrophil count, decreased white blood cell count, and anaemia. The addition of cadonilimab to first-line standard chemotherapy significantly improved progression-free survival and overall survival with a manageable safety profile in participants with persistent, recurrent, or metastatic cervical cancer. The data support the use of cadonilimab plus chemotherapy as an efficacious first-line therapy in persistent, recurrent, or metastatic cervical cancer. Akeso Biopharma.

Cadonilimab (PD-1/CTLA-4) in combination with lenvatinib in unresectable hepatocellular carcinoma (uHCC): A retrospective real-world study

BackgroundPrevious research has shown that combining tyrosine kinase inhibitors (TKIs) with immunotherapy results in synergistic clinical efficacy. Cadonilimab, the first approved bi-specific antibody targeting PD-1 and CTLA-4, was studied to evaluate its efficacy and safety in combination with Lenvatinib as a first-line treatment for patients with unresectable hepatocellular carcinoma (uHCC). MethodsA retrospective study was conducted on 29 uHCC patients diagnosed at Nanfang Hospital, Southern Medical University, between July 7, 2022, and March 3, 2023. Patients received Cadonilimab (10 mg/kg, IV, every 3 weeks) combined with Lenvatinib (8 mg, orally, daily). The primary endpoint was the objective response rate (ORR), with secondary endpoints including disease control rate (DCR), median progression-free survival (mPFS), median overall survival (mOS), median time to progression (mTTP), and safety. ResultsBy April 2023, 29 patients had been enrolled in the study. The ORR was 37.9 %, DCR was 82.8 %, mPFS was 8.1 months, mTTP was 8.2 months, and mOS was not reached. A total of 93.1 % of patients experienced at least one treatment-related adverse event (TRAE). The most common adverse events were weight loss (51.7 %), increased aspartate aminotransferase (48.3 %), leukocytopenia (48.3 %), and neutropenia (48.3 %). TRAEs of grade 3 or higher occurred in 51.7 % of patients, with no grade 4 TRAEs observed. ConclusionThis study demonstrated the efficacy and safety of this combination, potentially improving outcomes as a first-line therapy, and offering a novel therapeutic approach for advanced HCC.

First-line treatment with KN046, chemotherapy and palliative radiotherapy for advanced esophageal squamous cell carcinoma: an open-label, dose escalation, and dose expansion phase Ib trial

There is growing evidence to suggest that radiotherapy might enhance the efficacy of immunotherapy. This study aimed to assess the possibility of KN046, a bispecific antibody targeting PD-L1 and CTLA-4, combined with chemotherapy and palliative radiotherapy for advanced esophageal squamous cell carcinoma (ESCC). In this open-label, phase Ib trial, patients with advanced ESCC were administered chemotherapy with palliative radiotherapy, and KN046 in the predefined escalation dosages of 1, 3, or 5 mg/kg (every 3 weeks during chemotherapy cycles and every 2 weeks during KN046 maintenance). The chemotherapy regimen constituted cisplatin (75 mg/m2 i.v., d1) and paclitaxel (135–175 mg/m2 ivgtt., d1). Radiotherapy specifics, including site, timing, dose, and fragmentation pattern, were at the investigator’s discretion. The primary outcome was dose-limiting toxicity (DLT). From May 2019 to April 2021, 25 patients were enrolled across the dosage groups: 3 in 1 mg/kg, 12 in 3 mg/kg, and 10 in 5 mg/kg. No DLT was observed during the dose escalation. The objective response rate was 41.7% (95%CI 22.1–63.4), while the disease control rate was 87.5% (95%CI 67.6–97.3). At a median follow-up of 11.8 months, the median progression-free survival was 7.8 months (95%CI 5.2–9.7) and median overall survival was 15.9 months (95%CI 8.4-NE). Serious adverse events were reported in 48.0% of patients, predominantly leukopenia (16%), immune-mediated enterocolitis (12%), immune-mediated pneumonitis (8%), and neutropenia (8%). Combining KN046 with chemotherapy and palliative radiotherapy might be feasible, showing a favorable safety profile and notable efficacy in advanced ESCC patients.

Botensilimab, an Fc-enhanced anti-CTLA-4 antibody, is effective against tumors poorly responsive to conventional immunotherapy.

Conventional immune checkpoint inhibitors (ICI) targeting CTLA-4 elicit durable survival, but primarily in patients with immune-inflamed tumors. Although the mechanisms underlying response to anti-CTLA-4 remain poorly understood, Fc-gamma receptor (FcγR) IIIA co-engagement appears critical for activity, potentially explaining the modest clinical benefits of approved anti-CTLA-4 antibodies. We demonstrate that anti-CTLA-4 engineered for enhanced FcγR affinity leverages FcγR-dependent mechanisms to potentiate T cell responsiveness, reduce intratumoral Tregs, and enhance antigen presenting cell activation. Fc-enhanced anti-CTLA-4 promoted superior efficacy in mouse models and remodeled innate and adaptive immunity versus conventional anti-CTLA-4. These findings extend to patients treated with botensilimab, an Fc-enhanced anti-CTLA-4 antibody, with clinical activity across multiple poorly immunogenic and ICI treatment-refractory cancers. Efficacy was independent of tumor neoantigen burden or FcγRIIIA genotype. However, FcγRIIA and FcγRIIIA expression emerged as potential response biomarkers. These data highlight the therapeutic potential of Fc-enhanced anti-CTLA-4 antibodies in cancers unresponsive to conventional ICI therapy.

An open, prospective, single arm, phase II study of cadonilimab (PD-1/CTLA-4 bispecific antibody) with neoadjuvant chemotherapy in patients with advanced ovarian cancer: Interim analysis from the AK104-IIT-003 study.

e17552 Background: There is an unmet need to improve neoadjuvant chemotherapy (NAC) to decrease postoperative residual disease (R0 rate: 50%) and improve prognosis in ovarian cancer (OC). R0 rate and histopathological response of interval cytoreductive surgery (IDS) after NAC combined with immune checkpoint blockades were reported to be encouraging. Cadonilimab (AK104) is a tetravalent bispecific antibody targeting PD-1 and CTLA-4. In this study, we report the efficacy and safety of AK104 with NAC in patients with advanced-stage ovarian cancer (NCT05430906). Methods: This study is an open-label, prospective, single arm, phase II study of evaluating the efficacy and safety of cadonilimab combined with chemotherapy as neoadjuvant treatment for advanced ovarian cancer. Patients received neoadjuvant therapy of cadonilimab plus platinum-taxane chemotherapy (3 to 4 cycles) followed by surgery. Surgery would be performed within 30 days of completion of neoadjuvant therapy. The primary endpoint was the R0 rate. The secondary endpoints included objective response rate (ORR), disease control rate (DCR), chemotherapy response score (CRS), pathologic complete response(pCR), progression-free survival (PFS), and safety. A sample size of 35 achieves 80% power to detect a difference of 0.2 using a two-sided Z-test to estimate the standard deviation with a significance level (alpha) of 0.1. And the sample size was expected to be 40 cases to ensure that the FAS set contains 35 cases for analysis. Results: 17 patients were enrolled from Dec 12, 2022, to Dec 6, 2023. The median patient age was 57 years (range 45–70 years), and most patients presented with high-grade serous carcinoma (94.1%) and stage IVa (5.9%), IVb disease (76.5%). 15 (88.2%) patients had undergone IDS, with an R0 resection rate of 66.7%. ORR was 94.1%, with 1patient achieved CR and 15 patients achieved PR. 11.8% achieved pathological complete response, and 17.6% had a chemotherapy response score (CRS) of 3. PFS or OS data are not mature by cut-off date. Safety and adverse event (AE) were analyzed after completion of neoadjuvant therapy. Treatment-related AEs (TRAEs) of any grade were evaluated for all study populations. TRAEs of any grade occurred in 13 (76.5%) patients. Grade ≥3 TRAEs occurred in 3 (17.6%) patients. The most common TRAEs were thyroid dysfunction (23.5%) and bone marrow suppression (17.6%). Grade ≥ 3 irAE (immune⁃mediated colitis) occurred in 1 (5.9%) patient. All of the TRAEs, including severe AEs, were manageable, with no new safety concerns in this study. Conclusions: This study showed promising activity with a durable clinical response, supporting the potential of NAC with bispecific antibody AK104 in advanced-stage ovarian cancer. Meanwhile, long-term efficacy evaluation still needs following up. Clinical trial information: NCT05430906 .

Outcomes following long-term response to immune checkpoint inhibitors in patients with advanced melanoma.

9520 Background: Immune checkpoint inhibitors (ICI) targeting PD-1 and CTLA-4 can achieve durable responses. Historically, therapies in advanced malignancies were considered palliative, however long-term results from ICI melanoma studies suggest cure may be possible for some patients (pts). Despite clinical trial data, little is known about the risk, character, and clinical outcome of late recurrences after ICI. Methods: ICI treated pts with advanced melanoma who had a long-term disease control, defined as not requiring a subsequent line of systemic therapy within 3 years, were retrospectively identified at 11 centres. Those who had progressive disease managed with local therapies were included if no new systemic therapy was commenced within the 3 years. Demographics, disease characteristics, treatment, toxicity, recurrence patterns, management and outcomes were collected. Results: 567 pts were identified, with a median follow up of 7 years since start of therapy. At ICI commencement, 41% and 17% had M1c or M1d disease respectively, 26% had an elevated LDH, 33% were BRAF mutant and 24% had received prior therapy. The ICIs received were anti-PD-1 +/- an investigational agent (59.3%), anti-PD-1 plus anti-CTLA-4 (35.8%), or an anti-CTLA-4 (5%). The median duration of therapy was 18 months, with 31% of pts stopping due to toxicity. 63 pts (11.1%) had oligo-progression within 3 years from ICI start. 53 pts (9.3%) had progression after 3 years, with median time to progression of 16.3 months. Subsequent late progression was more common in those who had oligo-progression within 3 years of treatment compared to those who had not (14/63, 22% vs 39/504, 7.7%, P&lt;0.001). The risk of late progression was lower in those who achieved a complete response (CR) compared to those without a CR (23/369, 6.2% vs 30/198, 15.2%, P&lt;0.001). The landmark 5 year PFS was 95% compared to 89% in those with or without a CR respectively. Duration of therapy, treatment cessation due to toxicity, or corticosteroid use were not associated with the risk of late progression. Most late progression occurred within year 3 to 5 (38/53, 72%). 15 pts who progressed after 3 years were managed with local therapy alone. In progressors retreated with PD-1 alone as the next subsequent therapy, 14 of 26 (54%) responded (7 CR, 7 PR). In the total cohort, there were 31 (5.5%) deaths, 7 (1.2%) from melanoma. Of the pts with a CR, 14 (3.7%) died, only 1 (0.3%) from melanoma. Of the 53 pts who progressed after 3 years, 10 (19%) died, 7 (13%) from melanoma. Conclusions: In this population of pts with advanced melanoma with long term disease control from ICI, the risk of subsequent disease progression and death was low (1.2%). Predictors for late progression after 3 years were a non-CR best response and prior progression within 3 years. This and other data suggest a significant proportion of long-term ICI responders are likely cured, and may inform frequency and duration of follow up.

Neoadjuvant cadonilimab (PD-1/CTLA-4 bispecific antibody) plus FLOT chemotherapy in locally advanced gastric/gastroesophageal junction cancer (GC/GEJC): A prospective, multi-center, phase II study.

e16108 Background: FLOT remains the preferred neoadjuvant treatment (NAT) for locally advanced GC/GEJC, with evidence suggesting enhanced efficacy when plus PD-1 inhibitors. Cadonilimab, a bispecific antibody targeting PD-1 and CTLA-4, also exhibited survival benefits when combined with chemotherapy as first-line treatment for GC/GEJC. This study aimed to assess the efficacy and safety of Cadonilimab and FLOT as NAT in locally advanced GC/GEJC. Methods: Pathologically confirmed treatment-naïve patients (pts), aged 18-75, with radiologically evaluable primary GC/GEJC at stage cT3/4, ECOG PS 0-1, were enrolled. The study used simon-2 stage design with a total sample size of 38 pts and would be considered effective if more than 4 pts achieved pCR. Pts received surgery after completing NAT with Cadonilimab (10mg/kg, iv, Q3W) and FLOT (50mg/m² docetaxel, 85mg/m² oxaliplatin, 2600mg/m² 5-FU, and 200mg/m² leucovorin, iv). The primary endpoints were pCR and MPR rate. Secondary endpoints included ORR, DCR, R0 resection rate and safety (CTCAE 5.0). Results: In this phase II trial, initially enrolled 29 pts in stage I, with an additional 9 pts in stage II. Of the 34-evaluable pts, 30 pts underwent surgery. The median age was 57 years (range, 38-74), with 88.2% male and 64.7% diagnosed as stage cT4. According to RECIST1.1 criteria, 5 pts (14.7%) achieved CR, and 21pts (61.8%) achieved PR, with an ORR of 76.5% and DCR of 100.0%. According to Becker criteria for Tumor Regression Grade: 6 pts (20.0%) achieved TRG1a, 9 pts (30.0%) reached TRG1b, with a pCR rate of 20.0% and MPR rate of 50.0%. Pts with diffused and poorly differentiated tumors had higher rates of pCR and MPR (36.4%, 81.8%) than the overall population. A notable tumor downstaging was observed: 86.7% in T stage, 70.0% in N stage, and 70.0 in overall TNM stage. During the NAT phase, all 34 pts experienced TRAEs. Mild to moderate TRAEs (grade 1-2) were observed in 73.5% (25 patients), while 26.5% (9 patients) experienced grade 3 TRAEs. There were no reports of grade 4-5 or severe TRAEs. The most common TRAEs were nausea (100.0%), alopecia (97.1%), vomiting (85.3%), fatigue (85.3%), electrolyte disturbance (79.4%) and rash (73.5%). In post-surgery, all 30 pts achieved R0 resection. Surgical complications were relatively minor, predominantly fever (46.7%), ascites (30.0%) and pneumonia (23.3%). The survival benefit will be reported after the follow-up completed. Conclusions: Neoadjuvant Cadonilimab plus FLOT chemotherapy exhibit encouraging anti-tumor effectiveness and manageable toxicities, particularly in pts with diffused Lauren`s classification and poorly differentiation. This immunochemotherapy regimen might provide a promising alternative NAT option for locally advanced GC/GEJC. Clinical trial information: ChiCTR2200066893.

Two stage, multi-center trial of cadonilimab and LM-302 for patients with CLDN18.2+ biliary tract cancer (BTC) that failed chemotherapy and PD-(L)1 antibody (ZSAB-Calm).

e16152 Background: BTC is a lethal disease with limited effective treatments, especially for those who have failed immune checkpoint inhibitors (ICIs) plus chemotherapy. Cadonilimab, a tetrameric bispecific antibody targeting PD-1 and CTLA-4, showed promising safety profile and efficacy in several malignant tumors. LM-302 is a novel antibody-drug conjugate targeting CLDN18.2, a tight junction protein expressed on the cell surface of many solid tumors, including BTC. Here, we present preliminary data on the safety and efficacy of cadonilimab plus LM-302 in CLDN18.2+ BTC patients (pts) with prior treatment of ICI and chemotherapy. Methods: This ongoing study is a multicenter, two-stage, randomized phase Ib/II clinical trial. In the dose-escalation phase, 6 pts (no requirement for CLDN18.2) are enrolled, using "3+3" design to determine the RP2D. Pts will receive LM302 (1.6mg/kg or 1.8mg/kg Q2W) and cadonilimab (6mg/kg Q2W). The expansion stage is expected to enroll 90 pts (CLDN18.2 + staining in ≥40% of tumor cells), randomized into 3 arms with 30 patients each. Arm 1: cadonilimab (6mg/kg Q2W), Arm 2: LM-302 (1.8mg/kg, Q2W), Arm 3: cadonilimab (6mg/kg Q2W) and LM-302 (RP2D). The primary endpoints are the safety (CTCAE 5.0) in phase 1b and ORR (RECIST1.1) in phase 2. The secondary endpoints include DCR, PFS, OS and safety. Results: A total of 18 pts were enrolled from Aug 4, 2023 to Jan 15, 2024. Median age was 62 (range: 42-79), 44% were male. 61% have intrahepatic cholangiocarcinoma. 78% pts with distant metastasis were diagnosed as stage IV. In the dose-escalation phase, 7 pts were enrolled. The first pt was discontinued after only one dose due to percutaneous transhepatic cholangiography and drainage catheter infection and gastrointestinal bleeding (unrelated to treatment). No DLTs were observed. 7 (100%) pts experienced TRAEs. The most common TRAEs were bilirubin increase (71.4%) thrombocytopenia (57.1%), neutropenia (57.1%), infusion reactions (rash) (42.9%), leukopenia (42.9%), anemia (28.6%). Only 2 pts had grade 3 TRAEs including anemia(1pt), neutropenia, leukopenia and rash (1pt). There was no grade≥4 TRAE. Of the 6 efficacy-evaluable pts, 3 pts(CLDN18.2 expression in 30%, 40%, 80%)achieved PR resulting in a BOR of 50% in Phase Ib. The RP2D for LM-302 was 1.8mg/kg. In expansion phase, 11 pts with CLDN18.2+ BTC were randomly enrolled. The median number of treatment cycles was 2 (range 1-8), with 4 pts each in Arm 1 and Arm 2, and 3 pts in Arm 3. Among the 11 pts, 5 (45.5%) occurred TRAEs, with 3 pts in Arm 3 and 2 pts in Arm 1. The most common TRAEs were neutropenia (18.2%), neutropenia (18.2%). Only 1 pt in Arm 3 experienced grade 3 neutropenia. One pt had a SAE of myocardial infarction (unrelated to treatment). Conclusions: Cadonilimab combined with LM-302 has manageable safety and promising antitumor activity in CLDN18.2+ BTC. Clinical trial information: NCT05994001 .

Triage of advanced cervical cancer through immunotherapy induction (TRACTION).

TPS5622 Background: In advanced/recurrent cervical cancer, immune checkpoint inhibitors have emerged as an attractive alternative and have demonstrated impressive therapeutic responses. As a result, the combination of pembrolizumab with platinum/taxane chemotherapy with or without bevacizumab received FDA approval for first-line systemic therapy in persistent, recurrent, or metastatic PD-L1+ cervical cancer. However, this regimen demonstrates the greatest impact on survival when all four drugs are utilized and are not without the potential for significant toxicity. CheckMate-358 utilized two dosing regimens of ipilimumab and nivolumab in advanced/recurrent cervical cancer. In the preliminary results, the utilization of either dosing regimen resulted in remarkable, durable responses in chemo-naïve patients with the median overall survival not reached. Given the potential benefit of CTLA-4/PD-1 blockade in the upfront setting, we propose a phase II trial examining the strategy of induction immunotherapy with lorigerlimab (bispecific antibody targeting CTLA-4 and PD-1) in chemo-naïve cervical cancer patients not amenable to curative treatment. Methods: The study is a phase II, multi-site clinical trial conducted at MD Anderson Cancer Center and Lyndon B. Johnson General Hospital. In the induction phase, patients will receive intravenous (IV) lorigerlimab at the recommended phase II dose (6 mg/kg) for three 21-day cycles with a repeat CT scan performed at week 9 of treatment. Tumor response (by RECIST v1.1) to induction immunotherapy will be used to triage patients to either continuation of lorigerlimab (if at least stable disease) or standard of care treatment (if disease progression) in the triaged treatment phase. Lorigerlimab will be continued until progression or intolerable toxicity, for a maximum of 35 cycles. At any time point, all patients at first disease progression will subsequently receive physician’s choice standard of care systemic therapy with carboplatin/paclitaxel +/- pembrolizumab +/- bevacizumab and will be followed for survival. The primary objective is to estimate disease control rate. Secondary objectives are to determine objective response rate, duration of response, overall survival, progression-free survival, and safety (by CTCAE v5.0). Key eligibility criteria include 1) recurrent, metastatic, or persistent cervical cancer 2) squamous cell carcinoma, adenosquamous, or adenocarcinoma histologic subtype 3) not amenable to curative surgery or radiation. The trial is open with 14 of planned 40 patients enrolled at the time of submission. Clinical trial information: NCT05475171 .

Correlation of previous local vaccination site “flares” during immunotherapy for metastatic melanoma with complete responses to therapy.

e21534 Background: mRNA vaccines have been shown to stimulate T-cells targeting patient-specific tumor neoantigens. When combined with immune checkpoint inhibitors (ICI) in a randomized Phase II trial, mRNA vaccines demonstrated improvement in recurrence free survival and distant metastasis free survival compared to ICI alone. We retrospectively examined patients (pts) with advanced melanoma treated more than 5 years ago on clinical trials with adjuvant NYESO1 or mRNA vaccine therapies (VT) then ICI upon recurrence and analyzed biomarkers correlating with treatment response. Methods: This retrospective study examined 22 pts with advanced melanoma treated between 2004-2017 with adjuvant vaccine therapies (VT). 10 of the 22 pts subsequently developed recurrent disease and were treated with ICI. We evaluated disease free interval following ICI, sex, age, BRAF status, HLA type, site of primary and metastatic disease, initial vaccine treatment, vaccine toxicities, stage and sites of melanoma recurrence, ICI treatment, response and toxicities, vaccine site flares or cutaneous immune related adverse events (irAEs) following ICI. Results: Of the 22 patients (11 male, 11 female) treated with adjuvant VT, median age at first vaccine was 53 years old. HLA type was known for 11 pts. Stage at initial VT was IIB to IIIC. 14 pts recurred following adjuvant VT. Median time from vaccine initiation to melanoma recurrence was 3.2 years (range 6.5 months to 11 years). 10 pts received ICI for recurrent melanoma, 3 pts received ipilimumab, 2 anti-PD1 monotherapy, 4 ipilimumab and nivolumab, and 1 nivolumab/relatlimab. Stage at first ICI was IIIB to IV M1d. 9 pts experienced cutaneous irAEs. 7 pts experienced local vaccine site flare reactions following ICI treatment. Additionally, 2 pts experienced vitiligo, 2 with dermatologic flares (bullous pemphigoid and psoriatic rash), 2 with generalized rash that resolved with steroid cream. 1 pt did not experience rash, vaccine site flare, nor irAE dermatologic flare. Of the pts who recurred, 2 pts had BRAF V600E mutations, and 1 of these pts experienced vaccine flare, the other did not. 1 pt with a BRAF Q16L mutation did not have vaccine flare. 6 out of 7 BRAF wild type pts who recurred and received ICI experienced a localized vaccine site flare. Median disease-free interval following ICI treatment was 1.5 years (range 3 months to 9 years). All 10 pts are disease-free and off ICI being closely monitored. Conclusions: Evidence of prior localized vaccination “flare” may be a biomarker for a complete immunologic response in pts with metastatic disease treated with immunotherapy. ICI targeting CTLA-4 and/or PD-1 both triggered this localized vaccination site response, suggesting that T cell memory and immunologic activation against melanoma antigens translate into clinical responses.

A novel doxorubicin/CTLA-4 blocker co-loaded drug delivery system improves efficacy and safety in antitumor therapy

Doxorubicin’s antitumor effectiveness may be constrained with ineffective tumor penetration, systemic adverse effects, as well as drug resistance. The co-loading of immune checkpoint inhibitors and doxorubicin into liposomes can produce synergistic benefits and address problems, including quick drug clearance, toxicity, and low drug penetration efficiency. In our previous study, we modified a nanobody targeting CTLA-4 onto liposomes (LPS-Nb36) to be an extremely potent CTLA-4 signal blocker which improve the CD8+ T-cell activity against tumors under physiological conditions. In this study, we designed a drug delivery system (LPS-RGD-Nb36-DOX) based on LPS-Nb36 that realized the doxorubicin and anti-CTLA-4 Nb co-loaded and RGD modification, and was applied to antitumor therapy. We tested whether LPS-RGD-Nb36-DOX could targets the tumor by in vivo animal photography, and more importantly, promote cytotoxic T cells proliferation, pro-inflammatory cytokine production, and cytotoxicity. Our findings demonstrated that the combination of activated CD8+ T cells with doxorubicin/anti-CTLA-4 Nb co-loaded liposomes can effectively eradicate tumor cells both in vivo and in vitro. This combination therapy is anticipated to have synergistic antitumor effects. More importantly, it has the potential to reduce the dose of chemotherapeutic drugs and improve safety.

Abstract SY39-03: Illuminating the tumor immune GPCRome: Novel immunotherapy targets

Abstract Immune checkpoint blockade (ICB) targeting PD-1 and CTLA-4 has revolutionized cancer treatment. However, many cancers do not respond to ICB, prompting the search for additional strategies to achieve durable cancer remission. In this regard, G-protein-coupled receptors (GPCRs) represent the largest family of cell surface receptors involved in signal transduction and are the target of &amp;gt;30% of all approved drugs. GPCRs are the most pharmacologically favorable targets due to their druggability and direct relevance to many key physiological processes and a myriad of human diseases. However, GPCRs have been largely underexploited in oncology, and specifically understudied in cancer immunotherapy. GPCRs are primarily coupled to 4 distinct families of G proteins α subunit (Gαi, Gαs, Gαq, and Gα12), which dictate the signaling events controlled by each GPCR. Recently, we cross-integrated large single-cell RNA-sequencing datasets from CD8+ T cells covering 19 distinct cancer types and identified an enrichment of Gαs-coupled GPCRs on exhausted CD8+ T cells. These include GPCRs activated by inflammatory mediators, protons, neurotransmitters, and metabolites that accumulate in the tumor microenvironment, thereby promoting T cell dysfunction. We also developed transgenic mice expressing a chemogenetic CD8-restricted Gαs-GPCR and showed that a Gαs-PKA signaling axis promotes CD8+ T cell exhaustion and immunotherapy failure. These studies revealed that tumor cells may avoid immune elimination by stimulating Gαs-GPCRs on infiltrating CD8 T cells, thereby exposing novel druggable immune checkpoints that can be exploited therapeutically. We have recently extended these studies and mapped the expression patterns of all human GPCRs in nearly a million-tumor infiltrating immune cells. The emerging tumor-immune GPCR atlas may provide a valuable resource to explore the role of GPCRs in cancer immunology. Ultimately, our study may reveal new and exciting GPCR therapeutic targets to enhance the response to ICB, and help identify potential co-medications that may limit the success of ICB therapies. Citation Format: J. Silvio Gutkind. Illuminating the tumor immune GPCRome: Novel immunotherapy targets [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr SY39-03.

Sintilimab-induced severe erosive hemorrhagic gastritis and pyloric obstruction: a case report and literature review.

Immune checkpoint inhibitors could restore immune surveillance to attack tumor through targeting CTLA-4, PD-1 or PD-L1, and have achieved huge success. However, immune-related adverse events (irAEs) have been attracting attention as their application is expanding. Gastritis is relatively rare as a subtype of irAEs, particularly severe gastritis. Guidelines on its clinical management still remain undefined due to limited data. Sintilimab is a PD-1 inhibitor approved in China. Here we offer a case of sintilimab-induced severe erosive hemorrhagic gastritis and pyloric obstruction. Conventional proton pump inhibitors and mucosal protective agents did not take effect, so glucocorticoid was chosen. This severe gastritis was successfully cured finally. Our report describing its clinical performances, endoscopic characteristics and treatments, could assist clinicians to better know this rare irAE.

Abstract 1366: Dual immune checkpoint inhibition enhances the anti-tumor activity of trastuzumab deruxtecan in preclinical models

Abstract Background Trastuzumab deruxtecan (T-DXd) is an antibody-drug conjugate (ADC) composed of an anti-human epidermal growth factor receptor 2 (HER2) antibody, a cleavable tetrapeptide-based linker, and a topoisomerase I inhibitor payload. Recent clinical trials such as BEGONIA have highlighted the potential therapeutic benefit in combining T-DXd with immuno-oncology (IO) agents such as the PD-L1 inhibitor durvalumab. Here, we report preclinical findings demonstrating enhanced anti-tumor activity when T-DXd is combined with dual immune checkpoint inhibition. Methods HER2-expressing human cancer cell lines were treated in vitro with T-DXd and assessed for induction of immunogenic cell death (ICD) markers and expression of NK cell-activating ligands. Human macrophages and T cells were incubated with supernatants from treated cancer cells, and their activation status evaluated via flow cytometry. In vivo, the effects of T-DXd in combination with inhibitors of PD-L1, CTLA-4, and a monovalent bispecific anti-PD-1/TIGIT antibody - a murine surrogate of rilvegostomig - on tumor growth were evaluated in BALB/c mice bearing human HER2-low EMT6 murine mammary tumors. The anti-tumor activity of T-DXd in combination with volrustomig, a monovalent bispecific antibody targeting PD-1 and CTLA-4, was also assessed in hu-CD34+ NSG mice bearing HER2-low Caki-1 renal cell carcinoma tumors. Results In vitro, T-DXd induced ICD via DXd-mediated extracellular release of inflammatory mediators ATP and HMGB1, and cell surface exposure of calreticulin. This was associated with a greater than 2-fold increase in expression of NK cell-activating ligands, and activation of both macrophages and T cells. In immunocompetent mice bearing human HER2 expressing EMT6 tumors, T-DXd treatment drove tumor growth inhibition (53%, P &amp;lt;0.001) that was associated with an increase in tumoral T cells (2.6-fold, P &amp;lt;0.05) and increased CD8+ T cell expression of the immune checkpoints PD-1, TIGIT, and TIM-3. Tumor growth inhibition relative to vehicle-treated mice was enhanced when T-DXd was combined with inhibitors of PD-L1 (108%, P &amp;lt;0.001), PD-L1 plus CTLA-4 (172%, P &amp;lt;0.001), or a bispecific PD-1/TIGIT inhibitor (181%, P &amp;lt;0.001). Pharmacodynamic analysis revealed how the combination of T-DXd and PD-1/TIGIT inhibition increased tumoral NK cells (3.2-fold, P &amp;lt;0.001) and CD8+ T cells (3.8-fold, P &amp;lt;0.001) relative to vehicle. Consistent with findings in syngeneic models, the combination of T-DXd with a bispecific PD-1/CTLA-4 inhibitor also enhanced tumor growth inhibition in a humanised Caki-1 model (121%) compared to T-DXd alone (72%) (P &amp;lt;0.001). Conclusions These data provide insight into the clinical activity observed with T-DXd and provide scientific rationale for combination strategies with novel, bispecific IO agents targeting CTLA-4 or TIGIT in addition to the PD-1/PD-L1 axis. Citation Format: Liam Jenkins, Laura Kazlauskas, Matt Wilson, Scott A. Hammond, Theresa Proia, Jerome Mettetal. Dual immune checkpoint inhibition enhances the anti-tumor activity of trastuzumab deruxtecan in preclinical models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1366.

Anti-metabolic agent pegaspargase plus PD-1 antibody sintilimab for first-line treatment in advanced natural killer T cell lymphoma

Natural killer T cell lymphoma (NKTCL) is highly aggressive, with advanced stage patients poorly responding to intensive chemotherapy. To explore effective and safe treatment for newly diagnosed advanced stage NKTCL, we conducted a phase II study of anti-metabolic agent pegaspargase plus PD-1 antibody sintilimab (NCT04096690). Twenty-two patients with a median age of 51 years (range, 24–74) were enrolled and treated with induction treatment of pegaspargase 2500 IU/m2 intramuscularly on day 1 and sintilimab 200 mg intravenously on day 2 for 6 cycles of 21 days, followed by maintenance treatment of sintilimab 200 mg for 28 cycles of 21 days. The complete response and overall response rate after induction treatment were 59% (95%CI, 43–79%) and 68% (95%CI, 47–84%), respectively. With a median follow-up of 30 months, the 2 year progression-free and overall survival rates were 68% (95%CI, 45–83%) and 86% (95%CI, 63–95%), respectively. The most frequently grade 3/4 adverse events were neutropenia (32%, n = 7) and hypofibrinogenemia (18%, n = 4), which were manageable and led to no discontinuation of treatment. Tumor proportion score of PD-L1, peripheral blood high-density lipoprotein cholesterol, and apolipoprotein A-I correlated with good response, while PD-1 on tumor infiltrating lymphocytes and peripheral Treg cells with poor response to pegaspargase plus sintilimab treatment. In conclusion, the chemo-free regimen pegaspargase plus sintilimab was effective and safe in newly diagnosed, advanced stage NKTCL. Dysregulated lipid profile and immunosuppressive signature contributed to treatment resistance, providing an alternative therapeutic approach dual targeting fatty acid metabolism and CTLA-4 in NKTCL.

Dual Checkpoint Aptamer Immunotherapy: Unveiling Tailored Cancer Treatment Targeting CTLA-4 and NKG2A.

Recent strides in immunotherapy have illuminated the crucial role of CTLA-4 and PD-1/PD-L1 pathways in contemporary oncology, presenting both promises and challenges in response rates and adverse effects. This study employs a computational biology tool (in silico approach) to craft aptamers capable of binding to dual receptors, namely, inhibitory CTLA4 and NKG2A, thereby unleashing both T and NK cells and enhancing CD8+ T and NK cell functions for tumor cell lysis. Computational analysis highlighted AYA22T-R2-13 with HADDOCK scores of -78.2 ± 10.2 (with CTLA4), -60.0 ± 4.2 (with NKG2A), and -77.5 ± 5.6 (with CD94/NKG2A). Confirmation of aptamer binding to targeted proteins was attained via ELISA and flow cytometry methods. In vitro biological functionality was assessed using lactate dehydrogenase (LDH) cytotoxicity assay. Direct and competitive assays using ELISA and flow cytometry demonstrated the selective binding of AYA22T-R2-13 to CTLA4 and NKG2A proteins, as well as to the cell surface receptors of IL-2-stimulated T cells and NK cells. This binding was inhibited in the presence of competition from CTLA4 or NKG2A proteins. Remarkably, the blockade of CTLA4 or NKG2A by AYA22T-R2-13 augmented human CD8 T cell- and NK cell-mediated tumor cell lysis in vitro. Our findings highlight the precise binding specificity of AYA22T-R2-13 for CTLA4-B7-1/B7-2 (CD80/CD86) or CD94/NKG2A-HLA-E interactions, positioning it as a valuable tool for immune checkpoint blockade aptamer research in murine tumor models. These in vitro studies establish a promising foundation for further enhancing binding capacity and establishing efficacy and safety in animal models. Consequently, our results underscore the potential of AYA22T-R2-13 in cancer immunotherapy, offering high specificity, low toxicity, and the potential for cost-effective production.

KN046, a bispecific antibody against PD-L1 and CTLA-4, plus chemotherapy as first-line treatment for metastatic NSCLC: A multicenter phase 2 trial

KN046, a bispecific antibody targeting PD-L1 and CTLA-4, presents a promising therapeutic option for metastatic non-small cell lung cancer (NSCLC). In this multicenter phase 2 trial, patients with nonsquamous (non-sq) NSCLC receive pemetrexed, whereas those with sq-NSCLC receive paclitaxel, plus KN046 and carboplatin. Following four cycles, maintenance therapy includes KN046 with pemetrexed for non-sq-NSCLC and KN046 for sq-NSCLC. The objective response rate is 46.0%, and the median duration of response is 8.1months. The median progression-free and overall survival are 5.8 and 26.6months, respectively. The common adverse events include anemia (87.4%), loss of appetite (72.4%), and neutropenia (70.1%). The most prevalent immune-related adverse event is pruritus (28.7%). These findings indicate that first-line treatment with KN046 and chemotherapy is effective and tolerable in metastatic NSCLC patients, warranting further investigation in a larger phase 3 trial. The trial is registered at ClinicalTrials.gov (NCT04054531).

Development of Plant-Derived Bispecific Monoclonal Antibody Targeting PD-L1 and CTLA-4 against Mouse Colorectal Cancer.

Checkpoint blockade immunotherapy has revolutionized cancer treatment, with monoclonal antibodies targeting immune checkpoints, yielding promising clinical benefits. However, with the advent of resistance to immune checkpoint inhibitor treatment in clinical trials, developing next-generation antibodies with potentially increased efficacy is critical. Here, we aimed to generate a recombinant bispecific monoclonal antibody for dual inhibition of programmed cell death protein 1/programmed cell death ligand 1 and cytotoxic T-lymphocyte-associated protein 4 axes. The plant system was used as an alternative platform for bispecific monoclonal antibody production. Dual variable domain immunoglobulin atezolizumab × 2C8 is a plant-derived bispecific monoclonal antibody that combines both programmed cell death ligand 1 and cytotoxic T-lymphocyte-associated protein 4 blockade into a single molecule. Dual variable domain immunoglobulin atezolizumab × 2C8 was transiently expressed in Nicotiana benthamiana and the expression level was determined to be the highest after 4 days of infiltration. The size and assembly of the purified bispecific monoclonal antibody were determined, and its function was investigated in vitro and in vivo. The molecular structures of plant-produced dual variable domain immunoglobulin atezolizumab × 2C8 are as expected, and it was mostly present as a monomer. The plant-produced dual variable domain immunoglobulin atezolizumab × 2C8 showed in vitro binding to programmed cell death ligand 1 and cytotoxic T-lymphocyte-associated protein 4 proteins. The antitumor activity of plant-produced bispecific monoclonal antibody was tested in vivo by treating humanized Balb/c mice bearing a CT26 colorectal tumor. Plant-produced dual variable domain immunoglobulin atezolizumab × 2C8 significantly inhibited tumor growth by reducing tumor volume and weight. Body weight changes indicated that the plant-produced bispecific monoclonal antibody was safe and tolerable. Overall, this proof of concept study demonstrated the viability of plants to produce functional plant-based bispecific immunotherapy.