SAPPHIRE: phase III study of sitravatinib plus nivolumab versus docetaxel in advanced nonsquamous non-small-cell lung cancer

BACKGROUND

Checkpoint inhibitor (CPI) therapy revolutionized treatment for advanced non-small-cell lung cancer (NSCLC); however, most patients progress due to primary or acquired resistance. Sitravatinib is a receptor tyrosine kinase inhibitor that can shift the immunosuppressive tumor microenvironment toward an immunostimulatory state. Combining sitravatinib with nivolumab (sitra + nivo) may potentially overcome initial CPI resistance.

PATIENTS AND METHODS

In the phase III SAPPHIRE study, patients with advanced non-oncogenic driven, nonsquamous NSCLC who initially benefited from (≥4 months on CPI without progression) and subsequently experienced disease progression on or after CPI combined with or following platinum-based chemotherapy were randomized 1 : 1 to sitra (100 mg once daily administered orally) + nivo (240 mg every 2 weeks or 480 mg every 4 weeks administered intravenously) or docetaxel (75 mg/m2 every 3 weeks administered intravenously). The primary endpoint was overall survival (OS). The secondary endpoints included progression-free survival (PFS), objective response rate (ORR), clinical benefit rate (CBR), duration of response (DOR; all assessed by blinded independent central review), and safety.

RESULTS

A total of 577 patients included randomized: sitra + nivo, n = 284; docetaxel, n = 293 (median follow-up, 17.1 months). Sitra + nivo did not significantly improve OS versus docetaxel [median, 12.2 versus 10.6 months; hazard ratio (HR) 0.86, 95% confidence interval (CI) 0.70-1.05; P = 0.144]. The median PFS was 4.4 versus 5.4 months, respectively (HR 1.08, 95% CI 0.89-1.32; P = 0.452). The ORR was 15.6% for sitra + nivo and 17.2% for docetaxel (P = 0.597); CBR was 75.5% and 64.5%, respectively (P = 0.004); median DOR was 7.4 versus 7.1 months, respectively (P = 0.924). Grade ≥3 treatment-related adverse events were observed in 53.0% versus 66.7% of patients receiving sitra + nivo versus docetaxel, respectively.

CONCLUSIONS

Although median OS was numerically longer with sitra + nivo, the primary endpoint was not met in patients with previously treated advanced nonsquamous NSCLC. The safety profiles demonstrated were consistent with previous reports.

Phase III trial of sitravatinib plus nivolumab vs. docetaxel for treatment of NSCLC after platinum-based chemotherapy and immunotherapy (SAPPHIRE)

TPS9635

Background: Sitravatinib is an oral spectrum-selective tyrosine kinase inhibitor that targets the TAM (TYRO3/AXL/MERTK) and split (VEGFR2/KIT) family receptor tyrosine kinases (RTKs), as well as MET. Inhibition of TAM RTKs may promote the depletion of myeloid-derived suppressor cells (MDSCs) in the tumor microenvironment (TME) and repolarize tumor associated macrophages towards the pro-inflammatory M1 phenotype. Inhibition of the split RTKs may reduce immunosuppressive regulatory T cells in addition to MDSCs within the TME. Given these pleiotropic immune-stimulating effects, sitravatinib may reverse resistance to checkpoint inhibitor therapy (CIT) and augment the antitumor immune response of nivolumab in patients (pts) with non-small cell lung cancer (NSCLC). An ongoing Phase 2 study (MRTX-500) demonstrates clinical activity of this combination in pts with metastatic non-squamous NSCLC after progression on or after CIT. Methods: Global, randomized, open-label, Phase 3 study of sitravatinib in combination with nivolumab vs docetaxel in pts with advanced non-squamous NSCLC who have progressed on or after CIT. Pts must have also received platinum-based chemotherapy either in combination with CIT or prior to CIT. Pts are randomized (1:1) to receive oral sitravatinib 120 mg once daily in continuous 28-day cycles combined with nivolumab IV 240 mg every 2 weeks or 480 mg every 4 weeks vs treatment with docetaxel 75 mg/m2 IV every 3 weeks. Patients are stratified based on number of prior treatment regimens in the advanced setting, ECOG performance status, and presence of brain metastases. Key eligibility criteria include duration of treatment of CIT of at least 4 months, discontinuation of prior treatment with CIT < 90 days prior to the date of randomization, and absence of symptomatic or uncontrolled brain metastases. The primary endpoint is overall survival (OS). Key secondary endpoints include safety and tolerability, ORR, PFS, PROs, and PK. OS will be analyzed using Kaplan-Meier methods and the stratified log-rank test to estimate and compare the median OS between the two treatment arms with 95% CI. An IDMC will review safety at regular intervals and efficacy at a planned interim analysis based on OS. Enrollment is ongoing. Clinical trial information: NCT03906071 .

DGM1 may serve as a novel genetic biomarker of response to enzastaurin in glioblastoma

2023

Background: Despite countless clinical trials being conducted, little has changed over the last decade in the chemotherapies available for glioblastoma (GBM) with survival remaining poor. Meaningful advances in treating this deadly malignancy may rely on precision medicine. We discovered a novel pharmacogenomic biomarker for enzastaurin (enz) in treating lymphoma (lymph). We evaluated if this biomarker can be used to predict enz response in GBM. Methods: Biomarker discovery was performed by a genome-wide screen using DNA extracted from blood samples from a ph 3 enz lymph trial and confirmed in an independent ph 2 enz lymph trial. The biomarker was then evaluated for its predictability in GBM using the archived DNA samples from a prior ph 1/2 enz GBM trial. Results: A novel biomarker, Denovo Genomic Marker 1 (DGM1), a germline polymorphism on chromosome 8, was found to be highly correlated with response to enz in the two lymph trials. Using DNA extracted from blood of pts from the single-arm ph 1/2 study of newly diagnosed GBM receiving enz added to radiation and temozolomide (tmz), we found median OS for DGM1+ pts treated with enz was 18 mon vs 12.8 mon for DGM1- pts, HR (95% CI) 0.68 (0.25, 1.81), p = 0.12. In addition, we found pts in the GBM study receiving a mean daily dose of enz ≥ 245 mg had an OS of 19.8 mon vs 14.9 mon for pts receiving a mean daily dose of < 245 mg [HR (95% CI) 0.55 (0.34, 0.90)]; enz 500 mg/day was used in the lymph studies. Conclusions: These data are supportive of DGM1 as a potentially predictive biomarker for enz response in both lymph and GBM. There is an ongoing biomarker-driven pivotal ph 3 study in lymph at 500 mg/day, and DGM1 in GBM will be further evaluated in a planned randomized ph 2b study in newly diagnosed GBM with 500 mg/day of enz in combination with tmz.

ENGINE: Phase III randomized study of enzastaurin/R-CHOP versus placebo/R-CHOP in frontline high-risk diffuse large B-cell lymphoma patients with novel genomic biomarker DGM1

TPS7569

Background: Progress in genome technology allows analysis of previously completed trials to identify patients subgroups potentially benefiting from therapy. Enzastaurin is a potent inhibitor of protein kinase C beta (PKC- b) and suppresses the phosphoinositide 3-kinase (PI3K)/AKT pathway. The safety and efficacy of Enzastaurin has been tested in more than 60 clinical trials including 2 major studies in DLBCL: (1) PRELUDE (A phase III maintenance trial of Enzastaurin vs Placebo, N=758) ( Crump, 2016), and (2) S028 (A randomized phase II study of Enzastaurin/R-CHOP vs R-CHOP in frontline intermediate/high-risk DLBCL, N=101) ( Hainsworth, 2016). DNA samples extracted from blood of patients from PRELUDE were retrospectively genotyped using whole genome SNP arrays. From the genome wide screening a novel genetic biomarker, DGM1, was identified showing high correlation with response to Enzastaurin treatment ( Luo, ASH 2018). Importantly, these findings were replicated in the phase II S028 study. In the S028 study the hazard ratio (HR) for OS in high-risk (IPI ≥ 3) DGM1 positive (+) patients who received Enzastaurin/R-CHOP was 0.28 (0.1-0.81) when compared to subjects who received R-CHOP, a benefit favoring Enzastaurin (p=0.018). These data suggest that addition of Enzastaurin to R-CHOP may significantly improve outcome in frontline high-risk DGM1 (+) DLBCL. The ENGINE study was initiated to validate this finding in a prospective study. Methods: Adult patients must have untreated CD20+ DLBCL, IPI ≥ 3. Patients are randomized 1:1 to Enzastaurin/R-CHOP or Placebo/R-CHOP for 6 cycles during combination phase. Each subject’s treatment assignment will be unblinded after response assessment at the end of the combination phase. Subjects randomized to the investigational arm who have a complete or partial response will have the option to continue in the single agent phase to receive Enzastaurin for up to 2 additional years. The study intends to enroll approximately 235 patients with primary endpoint of OS in DGM1 (+) patients. The study is ongoing with 51 sites open in the US and China. As of 22 Jan 2019, 70 patients have been randomized. Clinical trial information: NCT03263026.

Clinical toxicity of antibody drug conjugates: a meta-analysis of payloads

Background Antibody drug conjugates (ADCs) utilize a monoclonal antibody to deliver a cytotoxic payload specifically to tumor cells, limiting exposure to healthy tissues. Major clinical toxicities of ADCs include hematologic, hepatic, neurologic, and ophthalmic events, which are often dose-limiting. These events may be off-target effects caused by premature release of payload in circulation. A meta-analysis was performed to summarize key clinical safety data for ADCs by payload, and data permitting, establish a dose-response model for toxicity incidence as a function of payload, dose/regimen, and cancer type. Methods A literature search was performed to identify and extract data from clinical ADC studies. Toxicity incidence and severity were collected by treatment arm for anemia, neutropenia, thrombocytopenia, leukopenia, hepatic toxicity, peripheral neuropathy, and ocular toxicity. Exploratory plots, descriptive summaries, and logistic regression modelling were used to explore Grade ≥ 3 (G3/4) toxicities and assess the impact of covariates, including cancer type and dose/regimen. Results The dataset contained 70 publications; quantitative analysis included 43 studies with G3/4 toxicity information reported for the endpoints above. G3/4 anemia, neutropenia and peripheral neuropathy were consistently reported for MMAE ADCs, thrombocytopenia and hepatic toxicity for DM1, and ocular toxicity for MMAF. Safety profiles of MMAE, DM1, and DM4 ADCs differed between solid and hematologic cancers. Conclusions Published ADC clinical data is limited by non-uniform reporting for toxicity and lack of dosing information, limiting the ability to develop quantitative models relating toxicity to exposure. However, the current analysis suggests that key G3/4 toxicities of ADCs in the clinic are likely off-target and related to payload.

ELOQUENT-1: A phase III, randomized, open-label trial of lenalidomide/dexamethasone with or without elotuzumab in subjects with previously untreated multiple myeloma (CA204-006)

TPS8113

Background: Elotuzumab (Elo) is a humanized monoclonal IgG1 antibody targeting the cell surface glycoprotein CS1, which is highly expressed on >95% of MM cells. In a MM xenograft mouse model, the combination of Elo + lenalidomide (Len) significantly reduced tumor volume in a synergistic manner compared with either agent alone. In a phase 2 study (N=73) of Elo (10 or 20 mg/kg) in combination with Len and low-dose-dexamethasone (Dex) in pts with RR MM, the 10 mg/kg dose group (n=36) demonstrated objective response rates (ORR) of 92% in all pts, and 100% in pts who had received only 1 prior therapy (n=16). The higher response rate in pts with fewer prior lines of therapy provides a rationale for investigating this combination earlier in the disease course. This randomized, open-label, phase 3 trial will determine if the addition of Elo to Len/Dex improves progression-free survival (PFS) in pts with newly diagnosed, untreated MM. Methods: Pts (N=750) with newly diagnosed symptomatic MM ineligible for stem cell transplant will be randomized in a 1:1 ratio to receive 28-day cycles of Len 25 mg PO (days1-21) and Dex 40 mg PO (days 1, 8, 15 and 22) with or without Elo. Elo dose and schedule is 10 mg/kg IV on days 1, 8, 15, 22 in the first 2 cycles and on days 1 and 15 of cycles 3-18 followed by 20 mg/kg on day 1 of cycle 19 onward. Dex 8 mg IV + 28 mg PO is used during the weeks with Elo. Treatment will continue until disease progression, death, or withdrawal of consent. Pts will be followed up for response every 4 weeks until progressive disease and for survival every 16 weeks. The primary endpoint is PFS (90% power for a hazard ratio [experimental to control arm] of 0.74) and the secondary endpoints are ORR and overall survival. Exploratory endpoints are safety, time to response, duration of response, time to subsequent therapy, health-related quality of life, and pharmacokinetics and immunogenicity of Elo. Potential biomarkers will also be assessed. As of January 1, 2012, 13 pts were enrolled and 9 pts were treated. NCT01335399.

Successful Treatment of Metastatic Androgen-Independent Prostate Carcinoma in a Transsexual Patient

The occurrence of prostate carcinoma in transsexual patients has rarely been reported. These cases present a unique challenge in that such patients are effectively receiving androgen deprivation therapy. By definition, their disease is androgen-independent prostate cancer, and the role of local therapy is undefined. We report on a male-to-female transsexual patient with metastatic prostate cancer treated successfully with combination chemotherapy after previous standard therapy failed.

Raloxifene, an oestrogen-receptor-beta-targeted therapy, inhibits androgen-independent prostate cancer growth: results from preclinical studies and a pilot phase II clinical trial

OBJECTIVES

To determine, in preclinical in vivo animal and in clinical studies, whether raloxifene (a selective oestrogen-receptor (ER) modulator that targets ER-beta and induces apoptosis in vitro in androgen-independent prostate cancer, AIPC cells) affects prostate cell differentiation, proliferation and carcinogenesis, and in the pilot phase II clinical trial, the response rate and duration of patients with AIPC treated with a daily oral dose of raloxifene.

PATIENTS, MATERIALS AND METHODS

Tumour proliferation rate in response to raloxifene treatment, and molecular markers of cell cycle and apoptosis, were evaluated in established ER-beta-positive androgen-dependent (AD) CWR22 and AI CWRSA9 human xenograft prostate cancer models. Twenty-one patients with AIPC and evidence of disease progression were enrolled into the clinical trial and given daily oral raloxifene.

RESULTS

There was significant growth inhibition by raloxifene in the ADPC and AIPC xenograft models (CWR22 68%, P < 0.010; CWRSA9 64%, P < 0.001), with no tumour regression. There was evidence of G1 arrest by increased p27kip1 expression in the raloxifene-treated group. Eighteen patients comprised the efficacy analysis, as three withdrew before the first evaluation. At the first evaluation, five men had stable disease and continued on the study for a median of five cycles. The longest response was 17 cycles. Drug related toxicity was minimal.

CONCLUSION

Raloxifene has activity in xenograft models, slowing disease progression. This translated to possible disease stabilization in patients with AIPC. Further studies are warranted.

Targeting the HER-kinase axis in cancer

The human epidermal growth factor receptor (HER) family of receptor tyrosine kinases controls critical pathways involved in the differentiation, growth, division, and motility of normal epithelial cells. Most human solid tumors are of epithelial origin. The process of malignant transformation and progression in many cancers may depend on activation of ligands and receptors that function as part of the HER-kinase pathway. This signaling axis has earned increased attention because of the development of antibodies and small-molecule tyrosine kinase inhibitors that specifically target components of the HER-kinase axis for cancer therapy. This review focuses on the basic biology underlying HER-kinase pathway activation and the current state of development for agents that target this axis. In particular, the importance of pan-HER inhibitors is discussed.