Prior VEGFR Research Articles

Biomarker analysis of zanzalintinib in clear cell renal cell carcinoma from STELLAR-001.

4545 Background: Zanzalintinib (zanza) is a novel oral multi-targeted TKI that inhibits several receptors, including VEGFR, MET, and TAM kinases. In an expansion cohort of previously treated patients (pts) with clear cell renal cell carcinoma (ccRCC) from the phase 1b STELLAR-001 study (NCT03845166), single-agent zanza showed encouraging activity (ORR, 38%; disease control rate, 88%), with responses seen in VEGFR TKI–pretreated pts, and a manageable safety profile (Pal, IKCS NA 2023:Abs 1). Here, we investigate biomarkers associated with zanza from the STELLAR-001 ccRCC expansion cohort. Methods: Adult pts (N=32) with advanced ccRCC, ECOG ≤1, and 1–3 prior systemic anticancer therapies received zanza 100 mg once daily until unacceptable toxicity or no longer deriving clinical benefit. Circulating plasma biomarkers and immune cell populations in blood were assessed at baseline and on-study. IHC for AXL, c-Met, phosphorylated Met, and VEGFR2 was performed on archival tissue. Associations between response to zanza and biomarker levels (at baseline and treatment-related changes) were investigated by comparing zanza responders (CR/PR; n=10) and non-responders (SD/PD; n=19). The relation between baseline biomarker levels and prior exposure to VEGFR TKI was also evaluated. P values were determined using a Wilcoxon test ( P<0.05 considered significant). Results: Zanza elicited significant changes in soluble biomarkers related to angiogenesis, tumor growth and metastasis, and immune modulation, including an increase in the circulating ligands VEGF ( P<0.001) and GAS6 ( P<0.001); decreases in ANG-1 ( P<0.001) and ANG-2 ( P<0.001), and the soluble angiogenic receptors, VEGFR2 ( P<0.001) and TIE-2 ( P<0.001). A decrease in levels of the chemokine, RANTES ( P<0.001), and an increase in IFNγ ( P=0.039) and the pro-apoptotic protein, granzyme B ( P<0.001) were also observed. An analysis of immune cell subsets showed that zanza raised activated cytotoxic T cell numbers ( P=0.002). Reductions in monocytes ( P=0.001), along with immunosuppressive subsets (total MDSCs [ P=0.013] and granulocytic MDSCs [ P=0.014]) were also observed. Response to zanza was associated with lower baseline levels of plasma biomarkers including CRP ( P=0.025) and HGF ( P=0.017), but not with any tissue biomarkers or zanza-mediated changes in immune cells or plasma biomarkers tested. Lower baseline levels of VEGFR2 were observed in pts with prior VEGFR TKI exposure ( P=0.042). Conclusions: Zanza in pts with advanced ccRCC leads to modulation of plasma biomarkers associated with angiogenesis and peripheral immune cell subsets consistent with its expected mechanism of action. The reduction in immunosuppressive immune cells and activation of effector immune cells by zanza support the rationale for combining zanza with immune checkpoint inhibitors. Given the small sample sizes, further investigation in larger studies is warranted. Clinical trial information: NCT03845166 .

Phase II trial of regorafenib in metastatic medullary thyroid carcinoma (MTC) and radioactive iodine refractory differentiated thyroid carcinoma (RAIR DTC).

6109 Background: Multi-kinase inhibitors show activity in both MTC & RAIR DTC. However, therapeutic options are limited after disease becomes refractory to one or two lines of standard of care therapies. We report here results of an investigator-initiated phase II clinical trial evaluating regorafenib in this population (NCT02657551). Methods: Patients with MTC (disease progression within 6-12 months, mo, prior to study registration) and RAIR DTC (progression within 12 mo) were enrolled regardless of prior lines of therapy. Regorafenib (each cycle 3 weeks ON/1 week OFF) was started at 80 mg daily, with planned escalation after 1 & 2 weeks to 120 mg daily & 160 mg daily, respectively, in absence of significant treatment-related adverse events (TRAEs). The highest tolerated dose was continued from cycle 2 onwards until progression. The primary endpoints were proportion progression-free at 10 months in MTC & overall response rate (ORR) by RECIST v1.1 in RAIR DTC. Simon two-stage design was utilized; MTC: <2 in 8 progression-free in first stage stops for futility, stage 2: enroll 13, >6/21 provides 81% power for proportion >20%; DTC: <3 in 9 in response in first stage stops for futility; stage 2: enroll 11, >7/20 provides 81% power for ORR >25%. Results: 17 patients (8 MTC, 9 DTC) were enrolled between April 2016 and October 2022. Among MTC, median (range) age was 54.7y (48.1, 62.8), 25% female. Among DTC, median age (range) was 62.8y (44.3, 75.8), 55.6% female. In MTC group, the proportion progression-free at 10 months was 12.5% (95% CI 0.3%, 52.7%) & did not meet the criteria to continue into 2nd stage. ORR in MTC group was 12.5% (95% CI 0.3%, 52.7%). In DTC group, ORR was 11.1% (95% CI 0.3%, 48.2%), & did not meet the criteria to continue into 2nd stage. No patients were receiving treatment at cutoff. Patients with MTC and DTC with objective responses (1 each) had received one (vandetanib) & no prior systemic therapy, respectively. The most common reason for discontinuation was disease progression in MTC (4, 50%) & DTC (5, 55.6%). Grade 3-4 TRAEs were observed in 8/17 (47.1%), most frequent were diarrhea, hypophosphatemia, & hypertension (each grade 3: 2, 11.7%). There were no treatment-related deaths. Median progression-free survival (PFS) in MTC & DTC were 5.3 (95% CI 3.6, 20.1) & 11.0 (95% CI 1.2, 24.0) mo, respectively. Median overall survival (OS) in MTC & DTC were 16.1 (95% CI 5.2, NA) and 20.1 (95% CI 1.6, NA) mo, respectively. Conclusions: Regorafenib clinical trial did not reach its primary endpoints in MTC and DTC. Analyses are planned to investigate impact of prior VEGFR inhibitor exposure, biomarkers and resistance mechanisms. Clinical trial information: NCT02657551 . [Table: see text]

A phase I/II study of talazoparib and axitinib in patients with advanced clear cell renal cell carcinoma.

4541 Background: Targeting the VEGF pathway is a backbone therapeutic for patients with advanced clear cell renal cell carcinoma (ccRCC). Tumor and tissue hypoxia may also lead to DNA repair suppression and PARPs are key regulators of DNA damage and genomic maintenance which interact with HIF proteins. Pairing a potent VEGFR TKI with a selective PARP inhibitor (PARPi) may lead to improved outcomes in ccRCC patients. Methods: This was a phase I/II, investigator-initiated, single-center, open-label study (NCT04337970) of talazoparib plus axitinib in previously treated ccRCC patients. In the phase Ib dose escalation, patients must have been previously treated with a PD-1/PD-L1 inhibitor with no maximum lines of prior therapy, and those in dose expansion were required to have prior treatment with a PD-1/PD-L1 inhibitor and prior VEGFR TKI, with a maximum of 2 prior lines of therapy. Patients received escalating doses of talazoparib (0.5 mg, 0.75 mg and 1 mg daily) with axitinib (5 mg twice daily) in a 3+3 design, with primary endpoint of safety and tolerability. After establishing the recommended phase II dose (RP2D), a dose expansion cohort enrolled patients in a Simon two-stage design with a primary endpoint of objective response (ORR), and secondary endpoints including progression-free survival (PFS). Results: From 2020-2023, 23 ccRCC patients were enrolled and treated on study. In the dose escalation, 15 patients enrolled across all 3 dose levels and there were 2 observed DLTS (1 in dose levels 2 and 3). Both DLTs was due to a lack of minimum exposure to study drugs during cycle 1 due to treatment-related toxicities. The maximum tolerated dose and RP2D established was 1 mg talazoparib daily with axitinib 5 mg twice daily. In the phase II dose expansion portion, an additional 9 patients were enrolled to evaluate preliminary efficacy. In total, 13/14 patients treated at the RP2D discontinued therapy due to progressive disease. The objective response rate (ORR) was 7% (90% CI 0, 30), with 1 patient achieving a partial response and 12 patients achieving stable disease (86%). With a median follow-up of 13.2 months (R: 6.6 -29), the median PFS was 6.1 months (95% CI 3.5, 8.4) and median overall survival (OS) was 27 months (95% CI 12- NE). Across the study, 13 (56%) patients had at least one treatment-emergent AE of grade 3+, and 9 (39%) patients had at least one treatment-related AE of grade 3+. Most common grade 3+ AEs included diarrhea, nausea, and anemia. Conclusions: This is the first clinical study evaluating combination PARPi and VEGFR TKI in metastatic ccRCC patients. This study established the RP2D and MTD of combination talazoparib and axitinib and demonstrated a tolerable safety profile across all dose escalation cohorts. The study did not meet the pre-defined efficacy threshold for further enrollment per Simon stage two design. Exploratory efforts to evaluate this treatment approach with tissue biomarker data remain ongoing. Clinical trial information: NCT04337970 .

Abstract B024: KO-2806, a next-generation farnesyltransferase inhibitor, potentiates the antitumor activity of cabozantinib in clear cell renal cell carcinoma models

Abstract Conventional treatments for advanced clear cell renal cell carcinoma (ccRCC) include tyrosine kinase inhibitors (TKI) that target angiogenesis, a critical element for ccRCC tumor growth and survival. Cabozantinib, a TKI that inhibits VEGFR, AXL, and MET, is an approved therapy in advanced RCC. However, cabozantinib has limited therapeutic benefit; for example, patients with prior VEGFR TKI therapy had an overall response rate of 21% and median progression-free survival of 7.4 months. Thus, there is an urgent need to identify combination drug partners that can improve the depth and/or durability of clinical responses to cabozantinib. Here, we present preclinical evidence that supports combining the farnesyltransferase inhibitor (FTI), KO-2806, with cabozantinib in ccRCC. KO-2806 is a next-generation farnesyltransferase inhibitor with increased potency and improved pharmacokinetic properties relative to earlier FTI drug candidates and is poised to enter a first-in-human clinical trial. We demonstrate that addition of KO-2806 enhanced tumor growth inhibition of cabozantinib in multiple ccRCC cell line- and patient-derived xenograft models, resulting in either tumor stasis or regression. Immunohistochemical analysis of angiogenic markers in 786-O tumors revealed that, consistent with its mechanism of action, cabozantinib significantly reduced angiogenesis, an effect that was deepened by KO-2806. In support of this, cell viability experiments performed in primary human endothelial cells showed that the combination of KO-2806 and cabozantinib was more effective in reducing cell viability than cabozantinib alone. In addition, we investigated the mechanism underlying the improved response of tumors with the KO-2806-cabozantinib combination by analyzing the major growth signaling pathways in 786-O tumors. Cabozantinib alone reduced both MAPK and PI3K/AKT/mTOR signaling, but addition of KO-2806 resulted in enhanced inhibition of mTOR signaling and increased cell cycle arrest compared to either agent alone. We hypothesize that exposure to anti-angiogenic TKIs render ccRCC tumors more hypoxic, and thus more reliant on compensatory, oncogenic mechanisms like mTOR signaling that allow them to adapt to a nutrient- and oxygen-deprived environment. Mechanistically, KO-2806 potently inhibits the farnesylation, and hence the activity, of the farnesylation-dependent protein RHEB, a positive regulator of mTOR, suggesting that the improved anti-tumor efficacy of the combination may arise through RHEB inhibition in this model. Further in vitro and in vivo studies are underway to establish the scope and mechanistic underpinnings of the effects of the KO-2806-cabozantinib combination and strengthen the therapeutic rationale for the investigation of this approach in the treatment of patients with ccRCC. Citation Format: Jovylyn Gatchalian, Linda Kessler, Hetika Patel, Stacia Chan, Francis Burrows, Shivani Malik. KO-2806, a next-generation farnesyltransferase inhibitor, potentiates the antitumor activity of cabozantinib in clear cell renal cell carcinoma models [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr B024.

Treatment Outcomes in Patients With Metastatic Renal Cell Carcinoma With Sarcomatoid and/or Rhabdoid Dedifferentiation After Progression on Immune Checkpoint Therapy.

Metastatic RCC with sarcomatoid and/or rhabdoid (S/R) dedifferentiation is an aggressive disease associated with improved response to immune checkpoint therapy (ICT). The outcomes of patients treated with VEGFR-targeted therapies (TT) following ICT progression have not been investigated. Retrospective review of 57 patients with sarcomatoid (S), rhabdoid (R), or sarcomatoid plus rhabdoid (S + R) dedifferentiation who received any TT after progression on ICT at an academic cancer center. Clinical endpoints of interest included time on TT, overall survival (OS) from initiation of TT, and objective response rate (ORR) by RECIST version 1.1. Multivariable models adjusted for epithelial histology, IMDC risk, prior VEGFR TT, and inclusion of cabozantinib in the post-ICT TT regimen. 29/57 patients had S dedifferentiation and 19 had R dedifferentiation. The most frequently used TT was cabozantinib (43.9%) followed by selective VEGFR TT (22.8%). The median time on TT was 6.4 months for all, 6.1 months for those with S dedifferentiation, 15.6 months for R dedifferentiation, and 6.1 months for S + R dedifferentiation. Median OS from initiation of TT was 24.9 months for the entire cohort, and the ORR was 20.0%. Patients with R dedifferentiation had significantly longer time on TT than those with S dedifferentiation (HR 0.44, 95% CI, 0.21-0.94). IMDC risk was associated with OS. A subset of patients with S/R dedifferentiation derive clinical benefit from TT after they have progressive disease on ICT. Patients with R dedifferentiation appeared to derive more benefit from TT than those with S dedifferentiation.

Updated results from a phase 2 study of the oral vascular endothelial growth factor receptor 2 (VEGFR2) inhibitor rivoceranib for recurrent or metastatic (R/M) adenoid cystic carcinoma (ACC).

6040 Background: ACC is a rare tumor that overexpresses VEGF, primarily affecting salivary glands. Often indolent, it can progress, with metastases common in the lungs, liver, and bone. There are no FDA-approved systemic treatments (tx) for R/M ACC. Rivoceranib is an oral tyrosine kinase inhibitor (TKI) that potently and selectively inhibits VEGFR2. Methods: In this single-arm, open-label multicenter trial, patients (pts) with R/M ACC with evidence of ≥20% progression by RECIST v1.1 or new lesions within the preceding 6 months (mos) were eligible, with no limit on prior tx. Pts received rivoceranib 700 mg daily until disease progression or withdrawal with pre-planned dose reductions for toxicity. Primary endpoint was overall response rate (ORR) per RECIST v1.1 by investigator (INV) and by Independent Review Committee (IRC). Secondary endpoints included duration of response (DoR), progression-free survival (PFS), time to progression (TTP), overall survival (OS), and safety exploratory analysis included disease control rate (DCR) and ORR using CHOI criteria by IRC. Results: As of 11/2022, 80 pts (72 evaluable) were enrolled in the US and Korea (53% male; median age, 54 yrs), and 6 pts remain on tx. Primary tumor sites: major (34%) and minor (59%) salivary glands and other (8%). 74 pts (93%) had metastatic disease. 61.3% had prior systemic tx (18% prior VEGFR TKI). INV and IRC-assessed efficacy data are listed in the table. ORR by CHOI was 52.5% (53.1% VEGFR TKI-naive and 50% VEGFR TKI treated). mOS was 25.3 mos (28.3 mos VEGFR TKI-naïve and 22.6 mos VEGFR treated). Common adverse events (AEs) were hypertension (66%), fatigue (64%), and nausea (54%). Grade ≥3 AEs that occurred in >5% of pts were hypertension (43%), stomatitis (8%), fatigue and anemia (6% each). There were 4 Grade 5 AEs (2 epistaxis [1 related], 1 acute respiratory failure, 1 respiratory failure). Conclusions: Updated results with additional 9-month follow-up data continue to demonstrate that Rivoceranib has clinical efficacy and a manageable safety profile in pts with R/M ACC. Clinical trial information: NCT04119453 . [Table: see text]

STELLAR: A Phase II, Open-Label, Single-Arm, Prospective Clinical Study of Tislelizumab Combined with Sitravatinib as Consolidation Treatment after Chemoradiotherapy in Locally Advanced, Unresectable Non-Small-Cell Lung Cancer

<h3>Purpose/Objective(s)</h3> Consolidation durvalumab has become the standard of care in patients with unresectable, stage III non-small-cell lung cancer (NSCLC) without disease progression after concurrent chemoradiation therapy (cCRT) based on the PACIFIC study. However, there are still about 44% of patients experiencing disease progression or recurrence within one year. New regimens for consolidation treatment are worth exploring to further improve survival for this population. Tislelizumab, an anti-PD-1 antibody engineered to minimize binding to FcγR on macrophages to abrogate antibody-dependent phagocytosis (a potential mechanism of resistance), has shown improved efficacy in advanced NSCLC with a tolerable safety profile. Sitravatinib is a spectrum-selective tyrosine kinase inhibitor targeting TAM (Tyro3, Axl, and Mer) and split tyrosine-kinase domain-containing receptors (VEGFR2, KIT), which may potentially augment immune checkpoint blockade through reducing the number of myeloid-derived suppressor cells/regulatory T cells and increasing the ratio of M1/M2 polarized macrophages. An early trial of tislelizumab plus sitravatinib showed acceptable tolerability and promising antitumor activity in advanced NSCLC. STELLAR (NCT05176925) is evaluating tislelizumab plus sitravatinib as consolidation treatment in patients with unresectable, locally advanced, stage III NSCLC after cCRT. <h3>Materials/Methods</h3> This phase II, open-label, single-arm, prospective study is enrolling patients aged from 18-75 years with histologically/cytologically confirmed, locally advanced, unresectable, stage III NSCLC who have not progressed following definitive, platinum-based cCRT, and with ECOG PS of 0 or 1. Patients will be excluded if they have a mixed histological type of small cell lung cancer and NSCLC, or receive prior anti-VEGF mAb, VEGFR TKI or ICI therapy. Patients will receive tislelizumab (200 mg, IV, d1, Q3W) combined with sitravatinib (starting dose 70 mg, po, qd; escalating to 100 mg, qd, after 2 cycles) for up to 1 year until disease progression, intolerable toxicity, withdrawal of consent or death. The primary endpoint is 1-year progression-free survival (PFS) rate by investigator assessment per RECIST v1.1. Secondary end points are PFS, objective response rate, duration of response and disease control rate assessed by investigators per RECIST 1.1, overall survival, time to distant metastasis, and safety. AEs will be graded by National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) v5.0. Enrollment begins in January 2022, and approximately 36 patients will be enrolled. <h3>Results</h3> N/A <h3>Conclusion</h3> N/A

Cabozantinib (C) plus atezolizumab (A) or C alone in patients (pts) with advanced non–small cell lung cancer (aNSCLC) previously treated with an immune checkpoint inhibitor (ICI): Results from Cohorts 7 and 20 of the COSMIC-021 study.

9005 Background: C, a multitargeted receptor tyrosine kinase inhibitor (TKI), promotes an immune-permissive environment that may enhance ICI activity. COSMIC-021 (NCT03170960) is a multicenter phase 1b study evaluating C + A in advanced solid tumors. In COSMIC-021, C + A demonstrated encouraging clinical activity in the cohort of pts with aNSCLC previously treated with ICIs (cohort 7 [C7]) (Neal. ASCO 2020. Abstr 9610). Updated outcomes of C + A in expanded C7 and outcomes for C alone in exploratory cohort 20 (C20) are presented. Methods: Pts with stage IV nonsquamous NSCLC without mutations in EGFR, ALK, ROS1, or BRAF V600E who progressed on one prior ICI and ≤2 prior lines of systemic anticancer therapy but no prior VEGFR TKI were eligible. Cohorts were not accrued contemporaneously. Pts received C 40 mg PO QD plus A 1200 mg IV Q3W (C7) or C alone 60 mg PO QD (C20). Primary endpoint was objective response rate (ORR) per RECIST v1.1 by investigator. Other endpoints included safety, duration of response (DOR), progression-free survival (PFS), and overall survival (OS). CT/MRI scans were performed Q6W for the first year and Q12W thereafter. Results: A total of 81 and 31 pts received C + A and C, respectively; baseline characteristics were as follows: median age, 67 y, 70 y; male, 57%, 58%; ECOG PS 1, 64%, 71%; liver metastasis, 21%, 23%; refractory to prior ICI (progressive disease [PD] as best response), 32%, 45%; median number of prior systemic therapies, 3 and 3. As of Nov 30, 2021, median follow-up (range) (mo) was 24.7 (10.7, 42.8) and 21.5 (17.3, 27.6) for C + A and C, respectively, with 6 (7%) and 1 (3%) on study treatment. Clinical activity was observed for C + A and C alone (Table). Most common treatment-related adverse events (TRAEs) of any grade for C + A and C, respectively, included diarrhea (40%, 42%), nausea (22%, 45%), decreased appetite (25%, 26%), vomiting (14%, 23%), and fatigue (28%, 19%); grade 3/4 TRAEs occurred in 44% and 52% and one grade 5 TRAE occurred in each cohort (pneumonitis [C + A] and gastric ulcer hemorrhage [C]). Conclusions: C + A and C demonstrated encouraging clinical activity with manageable toxicity in pts with aNSCLC previously treated with ICIs. A phase 3 trial (CONTACT-01; NCT04471428) of C + A vs docetaxel is ongoing in NSCLC previously treated with an ICI and platinum-containing chemotherapy. Clinical trial information: NCT03170960. [Table: see text]

Cabozantinib (C) versus placebo (P) in patients (pts) with radioiodine-refractory (RAIR) differentiated thyroid cancer (DTC) who have progressed after prior VEGFR-targeted therapy: Outcomes in prespecified subgroups based on prior VEGFR-targeted therapy.

6083 Background: Based on the results of the phase 3 COSMIC-311 trial, the multikinase inhibitor C was recently approved by the FDA for the treatment of RAIR DTC pts who progress after prior VEGFR-targeted therapies, such as lenvatinib (L) or sorafenib (S), and for whom there was no standard of care (Brose et al. Lancet Oncol. 2021). In an extended follow-up of the intent-to-treat (ITT) population, C-treated pts achieved a median (m) progression-free survival (PFS) of 11 months (mo) vs 1.9 mo with P (HR 0.22, 96% CI 0.15–0.32, P &lt;.0001); here we present outcomes for prespecified subgroups who received prior L, S, or both. Methods: Pts were randomized 2:1 to C (60 mg QD) or P. P pts could cross over to open-label C upon disease progression per confirmation by blinded independent radiology committee (BIRC). The primary endpoints were PFS (ITT) and objective response rate (first 100 randomized pts), per RECIST v1.1 by BIRC. Pts must have received L or S and progressed during or after 1–2 prior VEGFR inhibitors. Results: After a median follow-up of 10.1 mo, 258 pts (170 C, 88 P) had been randomized (data cutoff 8 Feb 2021); 96 (̃37%) had received prior S (no L), 102 (̃40%) prior L (no S), and 60 (̃23%) prior S and L. Median PFS was 16.6 for C vs 3.2 mo for P in prior S (no L) (HR 0.13, 95% CI 0.06–0.26); 5.8 vs 1.9 mo in prior L (no S) (HR 0.28, 95% CI 0.16–0.48), and 7.6 vs 1.9 mo in prior S and L (HR 0.27, 95% CI 0.13–0.54). In the C arm, 21% of pts in prior S (no L), 3% in prior L (no S), and 8% in S and L subgroups had confirmed partial response, and 1 pt had a confirmed complete response in prior L (no S); there were no responses with P. Stable disease as best response was 67% for C vs 45% for P in prior S (no L), 68% vs 32% in prior L (no S), and 74% vs 38% in prior S and L. Median duration of C-exposure was 7.0 mo in prior S (no L), 5.6 mo in prior L (no S) and 5.9 mo in prior S and L. Grade 3/4 treatment-emergent adverse events (TEAE) occurred in 63% pts in prior S (no L), 57% in prior L (no S), and 69% in prior S and L. Discontinuations of C due to TEAE occurred in 16% of pts in prior S (no L), 13% in prior L (no S), and 23% in prior S and L. There were no treatment-related deaths. Conclusions: In the extended follow-up, C maintained its superior PFS vs P irrespective of prior L and/or S. AEs in each subgroup were consistent with that of the overall population. This is also the first phase 3 study demonstrating a clinical benefit with C after prior L in RAIR DTC pts. Clinical trial information: NCT03690388.

LBA67 Cabozantinib versus placebo in patients with radioiodine-refractory differentiated thyroid cancer who have progressed after prior VEGFR-targeted therapy: Updated results from the phase III COSMIC-311 trial and prespecified subgroup analyses by prior therapy

At a preplanned interim analysis (median follow-up 6.2 mo) of the double-blind, phase 3 COSMIC-311 trial (NCT03690388), C significantly improved progression-free survival (PFS) versus P (HR 0.22, 96% CI 0.13–0.36; p<0.0001) in 187 pts with previously treated RAIR-DTC (Brose, Lancet Oncol; 2021). Pts must have received lenvatinib (L) or sorafenib (S) and progressed during or after 1–2 prior VEGFR inhibitors. We present final analysis with a longer follow-up of all randomized pts (ITT population) and for prespecified subgroups who received prior L, S, or both.

Late Breaking Abstracts

Late Breaking Abstracts

673P Cabozantinib-nivolumab (CN) vs. nivolumab-cabozantinib (NC) in patients (pts) with metastatic clear cell renal cell carcinoma (mRCC) following one prior VEGFR tyrosine kinase inhibitor (TKI): The CABIR multicentric matching-adjusted study

N and C are two approved agents after a prior TKI in mRCC pts. However, the optimal sequence, CN or NC, is still unknown. The superiority of C over everolimus in pts with prior anti-PD-1 (HR 0.22) in the METEOR trial suggests a sensitizing role of N. We conducted the CABIR study to identify the optimal sequence between CN and NC after one prior TKI.

Abstract CT165: A phase II trial of all-trans retinoic acid (ATRA) in advanced adenoid cystic carcinoma

Abstract Purpose: Recurrent or metastatic adenoid cystic carcinoma (R/M ACC) is a rare cancer often arising from the salivary glands of the head and neck. While effective therapies are lacking, preclinical models have suggested that retinoic acid agonists may inhibit ACC growth by blocking MYB binding at translocated gene enhancers. We conducted a phase II trial evaluating retinoic acid as a potential novel therapy for R/M ACC. Patients and methods: Patients with histologically confirmed R/M ACC of any primary site with measurable disease (RECIST v1.1), clinical or radiographic progression within 12 months prior to enrollment, and any number of prior lines of therapy were eligible. Cohort 1 (CH1) received ATRA 45 mg/m2 split oral daily dosing on days 1-14 of a 28-day cycle; cohort 2 (CH2) received the same dosing continuously; treatment continued until disease progression. The primary endpoint was best overall response: ≥5 patients in CH1 with disease in response (CR+PR) among N=25 (assuming ≥2 of N=14 accrued in first stage of a two-stage design had disease in response) provided 85% power to target a &amp;gt;10% response rate (one-sided 9% binomial test). Secondary endpoints: safety, progression-free survival (PFS), overall survival. Exploratory analyses: ATRA impact on MYB expression, define resistance mechanisms, and monitor circulating tumor DNA. All had targeted tumor sequencing prior to enrollment. Results: Between 8/2019 and 2/2020, N=14 enrolled in stage 1 CH1. Primary endpoint of response to continue accrual into stage 2 in CH1 was not met; by 5/2020, N=4 enrolled in CH2 when the trial closed to accrual (budget constraints). Among 18 patients, median age: 58, 61% (11/18) women; each patient had a median of 3 organs (range, 1-4) with metastatic disease. 39% had 2+ prior lines of therapy. Best overall response: CR+PR 0%; SD 61% (11/18); PD 28% (5/18); unevaluable 11% (2/18). Median duration of stability 3.5 months (range, 1-12.3+). One patient (CH1) remains on drug with SD &amp;gt;1 year. Half of those who received prior VEGFR therapy achieved SD (4/8). At a median follow-up of 7.9 months, median PFS was 3.2 months (95% CI, 1.8-3.9). N=1 required dose adjustment; N=1 came off drug for toxicity. There were no grade 3-4 adverse events (headache, dry skin were common); no deaths due to treatment. Median tumor mutational burden was 0 (range, 0-5). NOTCH1 was the most frequent alteration (4, 22%) with 2 evaluable NOTCH1-mutant patients exhibiting SD. Mutations in the PI3K pathway, TP53, and TERT promoter were common. Low MYB protein expression was associated with longer duration of stability (p&amp;lt;0.01). Conclusion: While the trial did not meet its prespecified overall response endpoint, SD was observed among R/M ACC patients with disease progression 12 months prior to enrollment. This combined with limited toxicity makes ATRA a treatment option for long-term growth stabilization alone, or worth exploring in combination with other agents for R/M ACC. Citation Format: Glenn J. Hanna, Anne O'Neill, Jennifer M. Cutler, Michelle Flynn, Tushara Vijaykumar, John R. Clark, Lori J. Wirth, Jochen H. Lorch, Jong C. Park, Jeffrey Mito, Jens G. Lohr, Jeffrey Kaufman, Leonard I. Zon, Robert I. Haddad. A phase II trial of all-trans retinoic acid (ATRA) in advanced adenoid cystic carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT165.

A phase II trial of all-trans retinoic acid (ATRA) in advanced adenoid cystic carcinoma

BackgroundEffective therapies are lacking for recurrent, metastatic adenoid cystic carcinoma (R/M ACC) and preclinical models suggest retinoic acid agonists inhibit ACC growth. This phase II trial evaluated all-trans retinoic acid (ATRA) as a novel therapy for ACC. MethodsPatients with R/M ACC (any site) with clinical and/or radiographic progression ≤12 months prior to study entry were eligible. Cohort 1 (CH1) received ATRA 45 mg/m2 split oral daily dosing on days 1–14 of a 28-day cycle; Cohort 2 (CH2) received the same dosing continuously. Primary endpoint was best overall response rate (CR + PR) (RECIST v1.1). Secondary endpoints: safety and progression-free survival (PFS). Exploratory analyses: ATRA impact on MYB expression and genomic predictors of response. ResultsEighteen patients enrolled. There were no responses, but 61% (11/18) had stable disease (SD) and 28% (5/18) progression as best response; 11% (2/18) unevaluable. Median duration of stability: 3.7 months (95%CI, 1.9–3.9). One patient (CH1) remains on drug with SD approaching 1 year. Half of those who received prior VEGFR therapy achieved SD (4/8). At median follow up of 7.9 months, median PFS was 3.2 months (95%CI, 1.8–3.9). N = 1 required dose adjustment; N = 1 came off drug for toxicity. There were no grade 3–4 adverse events. NOTCH1 and PI3K pathway alterations were most frequent. Low MYB protein expression was associated with longer duration of stability on ATRA (P < 0.01). Conclusion(s)While the trial did not meet its prespecified response endpoint, ATRA alone or in combination may be a low toxicity treatment for disease growth stabilization in R/M ACC.

Camrelizumab plus famitinib for advanced renal cell carcinoma or unresectable urothelial carcinoma: Updated results from a phase II trial.

4550 Background: Considering the synergistic/additive effect of PD-1 blockade and angiogenesis inhibition, we conducted an open-label, multi-center phase II study of camrelizumab (an anti-PD-1 antibody) plus famitinib (a TKI against VEGFR-2, PDGFR, c-kit, and FGFR) in pts with heavily treated advanced renal cell carcinoma (RCC) and unresectable urothelial carcinoma (UC). Methods: Based on an adaptive two-stage design, 22 pts were enrolled in the RCC and UC cohort, respectively, at stage 1; if there were ≥7 responders of the 22 pts, enrollment would be extend to 33 at stage 2. Pts received famitinib 20 mg orally QD plus camrelizumab 200 mg IV Q3W. Primary endpoint was ORR per RECIST v1.1. Preliminary data at stage 1 were reported at ASCO 2020 annual meeting (#5085). More than 7 pts in each cohort had CR/PR during stage 1; enrollment of stage 2 had been completed, and the data are firstly reported here. Results: 74 pts (38 advanced RCC and 36 unresectable UC) were enrolled from Jan 23, 2019 to Dec 14, 2020. In RCC cohort, 65.8% of pts had received ≥1 prior VEGFR inhibitors. In UC cohort, all pts had progressed on or relapsed after a platinum-containing chemotherapy. As of Jan 10, 2021, median time from enrollment to data cutoff was 18.8 mos (range, 8.5-22.7) for RCC cohort and 7.0 mos (range, 0.9-23.6) for UC cohort. In RCC cohort, ORR was 63.2% (95% CI, 46.0-78.2; 24 PRs), DCR was 89.5% (95% CI, 75.9-95.8), median DOR was not reached (range 2-19+ mos), mPFS was not reached, and 12-mo OS rate was 88.0%. Most pts (92.1%) had reduction in target lesions, and median reduction was 47% from baseline. ORR was 84.6% (95% CI, 57.8-97.3; 11/13) for untreated RCC pts and 52.0% (95% CI, 31.3-72.2; 13/25) for pre-treated pts; DCR was 100% (95% CI, 77.2-100.0) and 84.0% (95% CI, 65.3-93.6), mPFS was not reached and 13.4 mos (95% CI: 4.1-21.0), respectively. In UC cohort, of the 33 pts with post-baseline efficacy evaluation, ORR was 33.3% (95% CI, 19.8-50.4; 1 CR, 10 PRs), DCR was 60.6% (95% CI, 43.7-75.3), median DOR was not reached (range 1.0+-16.7+ mos), mPFS was 6.4 mos (95% CI, 2.1-11.8), and mOS was not reached. ORR trended to be higher for bladder cancer (43.8%, 7/16) than upper tract urothelial carcinoma (25.0%, 4/16). Treatment-related AEs (TRAEs) occurred in 97.3% of 74 pts. Grade 3 or 4 TRAEs occurred in 63.5% of pts, mainly hypertension (23.4%), decreased platelet count (21.3%), proteinuria (17.0%), anemia (14.9%), and palmar-plantar erythrodysesthesia syndrome (14.9%). 1 pt died of TRAE (multiple organ dysfunction syndrome). Conclusions: Camrelizumab plus famitinib showed potent anti-tumor activity in pts with advanced RCC and UC with no new safety concerns. Additionally, promising ORR and durable DOR were observed in pts with heavily-treated RCC. These results support further investigation in these settings. Clinical trial information: NCT03827837.

Cabozantinib versus placebo in patients with radioiodine-refractory differentiated thyroid cancer who have progressed after prior VEGFR-targeted therapy: Results from the phase 3 COSMIC-311 trial.

6001 Background: Cabozantinib (C), an inhibitor of VEGFR2, MET, AXL, and RET, showed clinical activity in patients (pts) with radioiodine (RAI)-refractory differentiated thyroid cancer (DTC) in phase 1/2 studies (Cabanillas 2017; Brose 2018). This phase 3 study (NCT03690388) evaluated the efficacy and safety of C vs placebo (P) in pts with RAI-refractory DTC who had progressed during/after prior VEGFR-targeted therapy for whom there is no standard of care. Methods: In this double-blind, phase 3 trial, pts were randomized 2:1 to receive C (60 mg QD) or P, stratified by prior lenvatinib treatment (L; yes, no) and age (≤65, &gt; 65 yr). Pts with RAI-refractory DTC must have received L or sorafenib for DTC and progressed during or following treatment with ≤ 2 prior VEGFR inhibitors. Pts randomized to P could cross over to open-label C upon disease progression per blinded independent radiology committee (BIRC). The primary endpoints were objective response rate (ORR) in the first 100 randomized pts and progression-free survival (PFS) in all randomized pts. PFS and ORR were assessed by BIRC per RECIST v1.1. The study was designed to detect an ORR for C vs P (2-sided α = 0.01) and a hazard ratio (HR) for PFS of 0.61 (90% power, 2-sided α = 0.04). A prespecified interim PFS analysis was planned for the ITT population at the time of the primary ORR analysis. Results: As of 19 Aug 2020,125 vs 62 pts had been randomized to the C and P arms, respectively; median age was 66 yr, 55% were female and 63% received prior L. Median (m) follow-up was 6.2 months (mo). At the planned interim analysis, the trial met the primary endpoint of PFS with C demonstrating significant improvement over P (HR 0.22, 96% CI 0.13–0.36; p &lt; 0.0001). mPFS was not reached for C vs 1.9 mo for P; PFS benefit was observed in all prespecified subgroups including prior L (yes, HR 0.26; no, HR 0.11) and age (≤65 yr, HR 0.16; &gt; 65 yr, HR 0.31). ORR was 15% for C vs 0% for P (p = 0.0281) but did not meet the prespecified criteria for statistical significance (p &lt; 0.01). A favorable OS trend was observed for C vs P (HR 0.54, 95% CI 0.27–1.11). Treatment-emergent adverse events (AEs) of any grade with higher occurrences in the C vs P arm included diarrhea (51% vs 3%), hand-foot skin reaction (46% vs 0%), hypertension (28% vs 5%), fatigue (27% vs 8%), and nausea (24% vs 2%); grade 3/4 AEs were experienced by 57% of pts with C vs 26% with P. Dose reductions due to any grade AEs occurred in 57% of pts with C vs 5% with P. Treatment discontinuations due to AEs not related to disease progression occurred in 5% of pts with C vs 0% with P. No treatment-related deaths occurred in either arm. Conclusions: C showed a clinically and statistically significant improvement in PFS over P in pts with RAI-refractory DTC after prior VEGFR-targeted therapy with no unexpected toxicities. C may represent a new standard of care in pts with previously treated DTC. Clinical trial information: NCT03690388.

Real-world data of cabozantinib in patients with VEGF-refractory metastatic renal cell carcinoma (mRCC): Results from the French Early Access Program (CABOREAL).

683 Background: Cabozantinib (Cabo) is approved in Europe for the treatment of mRCC in first line and after failure of tyrosine kinase inhibitors (TKI). We report the results from real-world use of Cabo in the French Early Access Program (EAP) (CABOREAL [NCT03744585]). Methods: Data were retrospectively collected from 26 centers. Patients (pts) were treated with Cabo during the Temporary Authorization for Use (ATU) period from Sep 12, 2016 to licensing in Feb 19, 2018. Pts were eligible after 2 prior VEGFR TKI unless clinical decision for 2nd line (L). The aim was to evaluate the use and activity of Cabo in real-life conditions. Overall survival (OS) was calculated from initiation of Cabo. Results: Overall, 410 pts were included. Median age was 63 years, 85% had clear-cell histology, 41% and 32% were intermediate/poor IMDC risk, respectively. Pts were mostly ECOG 1 (42%) or 2 (30%); 229 (56%) pts had bone metastasis (mets). Median follow-up was 14.4 months (m). Cabo was used as 2L, 3L and 4L or beyond for 101 (25%), 137 (33%) and 172 (41%) pts respectively; 204 pts (50%) were pretreated with nivolumab (Nivo). Activity results and dose reduction are summarized in the table. Starting dose was 60 mg (290 pts, 71%), 40 mg (109 pts, 27%) and 20 mg (8 pts, 2%). Treatment interruption occurred for 267 pts (65%), dose modification for 240 pts (59%) and schedule change for 64 pts (16%). Median daily dose was 40 mg/day. Treatment discontinuation occurred for 348 (85%) pts, with 86 (25%) due to adverse events. Notably, 184 (54%) pts received a subsequent systemic therapy. Conclusions: We report the largest real-world study of Cabo in mRCC to date. CABOREAL demonstrates that using dose modification, median Cabo duration was 7.6 m in a heavily pretreated population, with the longest treatment duration in patients with prior Nivo exposure. Clinical trial information: NCT03744585. [Table: see text]

Is body mass index (BMI) associated with favorable outcomes in metastatic renal cell carcinoma (mRCC) treated with nivolumab? An ancillary study of the NIVOREN-GETUG AFU-26 trial.

630 Background: Adipose tissue might affect response to immune checkpoint inhibitors (CPI) in cancer patients (pts). Higher BMI is associated with improved outcomes in mRCC under VEGFR TKI but BMI impact under CPI remains unclear. Methods: We analysed BMI in the NIVOREN GETUG AFU 26 study, a prospective study that evaluated the safety and efficacy of nivolumab in mRCC after failure of prior VEGFR inhibitors. We investigated the association between BMI, objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). BMI (weight/height 2) was classified according to the World Health Organization (WHO) categories: underweight as BMI &lt; 18.5; normal weight as 18.5 ≤ BMI ≤ 24.9; overweight as 25 ≤ BMI ≤ 29.9 and obesity as BMI ≥ 30. Survival distributions were compared using a Log-Rank test, supported by uni- and multivariate Cox regressions to estimate the Hazard Ratio (HR) and its 95% CIs. Median follow-up (FU) and the 95% CI were calculated using the reverse Kaplan–Meier method. Results: Overall, 708 pts were included in the BMI analysis: 20 pts (2.8%) were underweight, 322(45.5%) had normal weight, 255(36.0%) were overweight and 111(15.7%) obese. Median age was 64 years, 77.3% were male, performance status was ≥ 80% in 81.2%, and IMDC risk group was good, intermediate and poor in respectively 18.2%, 56.4%, 25.4%. Outcomes according to BMI is detailed in table, median FU was 23.9 months (95%CI 23.0-24.5). BMI adjusted to known prognostic factors was not significant in the multivariate analysis. Conclusions: Higher BMI patients seems to have better outcomes with nivolumab in mRCC. Further characterisation is on-going to explore the relation of BMI with established risk factor in pts under CPI in mRCC.[Table: see text]

TIVO-3: Subgroup analysis of progression-free survival of tivozanib compared to sorafenib in subjects with refractory advanced renal cell carcinoma (RCC).

4572 Background: Tivozanib (T) is a biochemically potent and highly selective VEGF tyrosine kinase receptor inhibitor in clinical development in RCC. The TIVO-3 trial in 3rd and 4th line subjects with metastatic (m) RCC showed a median progression free survival (mPFS) of 5.6 months (mos) for T compared to 3.9 mos for sorafenib (S) (p = 0.017, HR = 0.73). Methods: Subjects with mRCC who failed 2 or 3 prior systemic regimens, one of which included a VEGFR TKI other than S or T, were stratified by IMDC risk category and type of prior therapy (two TKIs; TKI plus checkpoint; TKI + other) then randomized in a 1:1 ratio to T or S. The primary objective was to compare PFS by blinded independent radiological review. Pre-specified subgroups included prior treatment, IMDC prognostic group, and demographic characteristics. Results: Tivozanib demonstrated PFS benefit in all subgroups including men, women, patients over 65, and under 65. The hazard ratio was the same for patients enrolled in North America and the EU. Patients with ECOG performance status (PS) of 0 had a lower HR than patients with ECOG PS of 1. There was an increase in HR from IMDC favorable vs IMDC intermediate vs IMDC poor. PFS favored tivozanib in patients who had two prior lines of therapy, those treated with three prior lines, those with a prior checkpoint inhibitor, or with two prior VEGFR TKIs. Conclusions: Tivozanib improved PFS vs. sorafenib across several subgroups in TIVO-3. Patients with favorable and intermediate IMDC risk and ECOG PS 0 seemed to derive the most benefit. Patients treated with a prior checkpoint inhibitor or two VEGFR-TKIs had a longer PFS than patients treated on sorafenib. Clinical trial information: NCT02627963. [Table: see text]

Analysis of overall survival (OS) based on early tumor shrinkage in the phase III METEOR study of cabozantinib (cabo) versus everolimus (eve) in advanced renal cell carcinoma (RCC).

550 Background: In the phase 3 METEOR study (NCT01865747), cabo improved OS (median 21.4 vs 16.5 mo; HR, 0.66; 95% CI, 0.53–0.83), progression-free survival and objective response rate compared with eve in patients (pts) with previously treated advanced RCC (Choueiri 2016). Retrospective studies have shown that early tumour shrinkage (eTS), based on target lesion reduction from baseline to first post-baseline scan, has predictive value for targeted therapies in RCC (Grunwald 2015; Grunwald 2016); here we evaluate its impact on OS in METEOR. Methods: In total, 658 pts were randomized 1:1 to receive cabo (60 mg qd) or eve (10 mg qd), stratified by MSKCC risk group and number of prior VEGFR TKIs. Target lesion size was assessed by independent radiology review using CT/MRI scans at baseline, every 8 wk for the first 12 mo and every 12 wk thereafter. Median OS was estimated for pts with ≥30% eTS, any eTS or no eTS at first post-baseline scan (week 8); data cutoff, 2 October 2016 (Motzer 2018). Results: Median follow-up was 28 mo (IQR 25, 30). Median (range) time to objective response was 1.91 (1.6, 11.0) mo with cabo and 2.14 (1.9, 9.2) mo with eve, and corresponded to the time to the first post-baseline scan. A greater proportion of pts had ≥30% eTS with cabo (20%) than with eve (5%) and the rate of any eTS was higher in the cabo arm (73%) than with eve (47%; Table). Median OS with cabo vs eve for pts with ≥30% eTS was not reached (NR; 95% CI, 23.7–NR) vs 10.2 mo (95% CI, 3.9–NE), respectively (stratified HR, 0.45; 95% CI, 0.21–0.95; p&lt;0.05). Median OS with cabo vs eve for pts with any eTS was 23.7 (95% CI, 21.7–27.7) vs 17.3 mo (95% CI, 15.4–20.8), respectively; (stratified HR, 0.62; 95% CI, 0.48–0.80; p&lt;0.05). OS was similar for cabo and eve for pts with no eTS. Conclusions: Cabo demonstrated a higher rate and greater magnitude of eTS at first post-baseline scan compared with eve, and eTS was associated with prolonged OS in pts treated with cabo. Clinical trial information: NCT01865747. [Table: see text]