Extended evaluation of a phase 1/2 trial on dosing, safety, immunogenicity, and overall survival after immunizations with an advanced-generation Ad5 [E1-, E2b-]-CEA(6D) vaccine in late-stage colorectal cancer.

A phase 1/2 clinical trial evaluating dosing, safety, immunogenicity, and overall survival on metastatic colorectal cancer (mCRC) patients after immunotherapy with an advanced-generation Ad5 [E1-, E2b-]-CEA(6D) vaccine was performed. We report our extended observations on long-term overall survival and further immune analyses on a subset of treated patients including assessment of cytolytic T cell responses, T regulatory (Treg) to T effector (Teff) cell ratios, flow cytometry on peripheral blood mononuclear cells (PBMCs), and determination of HLA-A2 status. An overall survival of 20 % (median survival 11 months) was observed during long-term follow-up, and no long-term adverse effects were reported. Cytolytic T cell responses increased after immunizations, and cell-mediated immune (CMI) responses were induced whether or not patients were HLA-A2 positive or Ad5 immune. PBMC samples from a small subset of patients were available for follow-up immune analyses. It was observed that the levels of carcinoembryonic antigen (CEA)-specific CMI activity decreased from their peak values during follow-up in five patients analyzed. Preliminary results revealed that activated CD4+ and CD8+ T cells were detected in a post-immunization sample exhibiting high CMI activity. Treg to Teff cell ratios were assessed, and samples from three of five patients exhibited a decrease in Treg to Teff cell ratio during the treatment protocol. Based upon the favorable safety and immunogenicity data obtained, we plan to perform an extensive immunologic and survival analysis on mCRC patients to be enrolled in a randomized/controlled clinical trial that investigates Ad5 [E1-, E2b-]-CEA(6D) as a single agent with booster immunizations.

Derazantinib alone and with atezolizumab in metastatic urothelial carcinoma with activating FGFR aberrations.

BACKGROUND: This Phase 1b/2 study assessed the efficacy in terms of objective response rate (ORR) of the FGFR1/2/3 kinase inhibitor derazantinib as monotherapy or in combination with atezolizumab in patients with metastatic urothelial cancer (mUC) and FGFR1-3 genetic aberrations (FGFR1-3GA). METHODS: This multicenter, open-label study comprised 5 substudies. In Substudies 1 and 5, patients with mUC with FGFR1-3GA received derazantinib monotherapy (300 mg QD in Substudy 1, 200 mg BID in Substudy 5). In Substudy 2, patients with any solid tumor received atezolizumab 1200 mg every 3 weeks plus derazantinib 200 or 300 mg QD. In Substudy 3, patients with mUC harboring FGFR1-3GA received derazantinib 200 mg BID plus atezolizumab 1200 mg every 3 weeks. In Substudy 4, patients with FGFR inhibitor-resistant mUC harboring FGFR1-3GA received derazantinib 300 mg QD monotherapy or derazantinib 300 mg QD plus atezolizumab 1200 mg every 3 weeks. RESULTS: The ORR for Substudies 1 and 5 combined was 4/49 (8.2%, 95% confidence interval = 2.3% to 19.6%), which was based on 4 partial responses. The ORR in Substudy 4 was 1/7 (14.3%, 95% confidence interval = 0.4% to 57.9%; 1 partial response for derazantinib 300 mg monotherapy, zero for derazantinib 300 mg plus atezolizumab 1200 mg). In Substudy 2, derazantinib 300 mg plus atezolizumab 1200 mg was identified as a recommended dose for Phase 2. Only 2 patients entered Substudy 3. CONCLUSIONS: Derazantinib as monotherapy or in combination with atezolizumab was well-tolerated but did not show sufficient efficacy to warrant further development in mUC. Clinicaltrials.gov NCT04045613, EudraCT 2019-000359-15.

Novel adenoviral vector induces T-cell responses despite anti-adenoviral neutralizing antibodies in colorectal cancer patients.

First-generation, E1-deleted adenovirus subtype 5 (Ad5)-based vectors, although promising platforms for use as cancer vaccines, are impeded in activity by naturally occurring or induced Ad-specific neutralizing antibodies. Ad5-based vectors with deletions of the E1 and the E2b regions (Ad5 [E1-, E2b-]), the latter encoding the DNA polymerase and the pre-terminal protein, by virtue of diminished late phase viral protein expression, were hypothesized to avoid immunological clearance and induce more potent immune responses against the encoded tumor antigen transgene in Ad-immune hosts. Indeed, multiple homologous immunizations with Ad5 [E1-, E2b-]-CEA(6D), encoding the tumor antigen carcinoembryonic antigen (CEA), induced CEA-specific cell-mediated immune (CMI) responses with antitumor activity in mice despite the presence of preexisting or induced Ad5-neutralizing antibody. In the present phase I/II study, cohorts of patients with advanced colorectal cancer were immunized with escalating doses of Ad5 [E1-, E2b-]-CEA(6D). CEA-specific CMI responses were observed despite the presence of preexisting Ad5 immunity in a majority (61.3 %) of patients. Importantly, there was minimal toxicity, and overall patient survival (48 % at 12 months) was similar regardless of preexisting Ad5 neutralizing antibody titers. The results demonstrate that, in cancer patients, the novel Ad5 [E1-, E2b-] gene delivery platform generates significant CMI responses to the tumor antigen CEA in the setting of both naturally acquired and immunization-induced Ad5-specific immunity.

Zanubrutinib in patients with previously treated B-cell malignancies intolerant of previous Bruton tyrosine kinase inhibitors in the USA: a phase 2, open-label, single-arm study.

BACKGROUND: We hypothesised that zanubrutinib, a highly selective next-generation Bruton tyrosine kinase (BTK) inhibitor, would be a safe and active treatment for patients intolerant of ibrutinib, acalabrutinib, or both. We aimed to assess whether zanubrutinib would prolong treatment duration by minimising treatment-related toxicities and discontinuations in patients with previously treated B-cell malignancies. METHODS: This ongoing, phase 2, multicentre, open-label, single-arm study was done in 20 centres in the USA. Patients aged 18 or older with previously treated B-cell malignancies (chronic lymphocytic leukaemia, small lymphocytic lymphoma, mantle cell lymphoma, Waldenström macroglobulinaemia, or marginal zone lymphoma) who became intolerant of ibrutinib, acalabrutinib, or both, were orally administered zanubrutinib 160 mg twice daily or 320 mg once daily per investigator. The primary endpoint was recurrence and change in severity of ibrutinib or acalabrutinib intolerance events based on investigator-assessed adverse events. Secondary endpoints were investigator-assessed overall response rate; duration of response; disease control rate; and progression-free survival. Analyses included all patients who received any dose of the study drug. This study is registered with ClinicalTrials.gov, NCT04116437. FINDINGS: Between Oct 14, 2019, and Sept 8, 2021, 67 patients (36 [54%] men and 31 [46%] women) who were intolerant of ibrutinib (n=57; cohort 1) or of acalabrutinib or acalabrutinib and ibrutinib (n=10; cohort 2) were enrolled. 63 (94%) patients were White, one (2%) had multiple ethnicities, and three (5%) had unreported or unknown ethnicity. Most intolerance events (81 [70%] of 115 for ibrutinib; 15 [83%] of 18 for acalabrutinib) did not recur with zanubrutinib. Of the recurring events, seven (21%) of 34 ibrutinib intolerance events and two (67%) of three acalabrutinib intolerance events recurred at the same severity with zanubrutinib; 27 (79%) ibrutinib intolerance events and one (33%) acalabrutinib intolerance event recurred at a lower severity with zanubrutinib. No events recurred at higher severity. No grade 4 intolerance events recurred. 64 (96%) of 67 patients had one or more adverse events with zanubrutinib; the most common adverse events were contusion (in 15 [22%] of 67 patients), fatigue (14 [21%]), myalgia (ten [15%]), arthralgia (nine [13%]), and diarrhoea (nine [13%]). Atrial fibrillation occurred in three (4%) patients (all grade 2). Eight (12%) of 67 patients had serious adverse events (anaemia, atrial fibrillation, bronchitis, COVID-19, COVID-19 pneumonia, febrile neutropenia, salmonella gastroenteritis, transfusion reaction, trigeminal nerve disorder, and urinary tract infection). No treatment-related deaths occurred. The median follow-up time was 12·0 months (IQR 8·2-15·6). Among the 64 efficacy-evaluable patients, disease control rate was 93·8% (60; 95% CI 84·8-98·3) and overall response rate was 64·1% (41; 95% CI 51·1-75·7). The median duration of response was not reached; the 12-month event-free duration of response rate was 95·0% (95% CI 69·5-99·3). Similarly, median progression-free survival was not reached; 18-month progression-free survival was 83·8% (95% CI 62·6-93·6). INTERPRETATION: Patients intolerant of previous BTK inhibitors have limited treatment options. These results suggest that zanubrutinib, a safe and viable treatment for patients with B-cell malignancies, might fill that unmet need for those who exhibit intolerance to ibrutinib or acalabrutinib. FUNDING: BeiGene.

A Randomized, Phase II Trial of Cetuximab With or Without PX-866, an Irreversible Oral Phosphatidylinositol 3-Kinase Inhibitor, in Patients With Metastatic Colorectal Carcinoma.

BACKGROUND: The phosphotidylinositol-3 kinase (PI3K)/serine-threonine kinase/mammalian target of rapamycin signaling pathway is frequently altered in colorectal cancer (CRC). PX-866 is an oral, irreversible, pan-isoform inhibitor of PI3K. This randomized phase II study evaluated cetuximab with or without PX-866 in patients with metastatic, anti-epidermal growth factor receptor-naive, KRAS codon 12 and 13 wild-type CRC. PATIENTS AND METHODS: Patients with metastatic CRC who had received both oxaliplatin and irinotecan were randomized (1:1) to cetuximab (400 mg/m2 loading then 250 mg/m2 weekly) with or without PX-866 (8 mg orally daily; arms A and B, respectively). The primary endpoint was progression-free survival (PFS). Secondary endpoints included objective response rate, overall survival (OS), toxicity, and correlation of relevant biomarkers with efficacy outcomes. RESULTS: A total of 85 patients were enrolled. The median PFS was 59 days versus 104 days for arms A (cetuximab + PX-866) and B (cetuximab alone), respectively (P = .77). OS between the 2 arms (266 vs. 333 days for arm A vs. B) were similar (P = .83). Overall toxicity, including treatment-related toxicity, was higher in arm A compared with arm B, especially in terms of all-grade nausea (66% vs. 37%), vomiting (50% vs. 29%), diarrhea (64% vs. 18%), and rash (66% vs. 37%). Grade 3 diarrhea occurred in 19% of patients in Arm A and 0% in Arm B. PIK3CA mutations and PTEN loss by immunohistochemistry were infrequently seen. CONCLUSION: The addition of PX-866 to cetuximab did not improve PFS, objective response rate, or OS in patients with metastatic CRC. The combination arm had greater toxicity and may have been harmful in this study.