Venous thromboembolism in adrenocortical carcinoma: a retrospective analysis

BACKGROUND

Venous thromboembolism (VTE) is a leading cause of death in patients with cancer. Limited data exist about VTE in patients with adrenocortical carcinoma (ACC). The primary objective of this study was to identify the prevalence of VTE in a cohort of patients with ACC. Secondary objectives were to determine the impact of VTE events on overall survival (OS) and to describe the characteristics of VTE in patients with ACC.

PATIENTS AND METHODS

We retrospectively reviewed data from 289 patients with ACC cared for at a major referral center from February 2010 to June 2022.

RESULTS

VTE prevalence was 18.7% (54 events). Thirty patients (55.6%) had pulmonary embolism (PE); 12 patients (22.2%) had deep vein thrombosis (DVT); and 12 patients (22.2%) had both PE and DVT. VTE occurred after ACC diagnosis in 50 patients (92.6%) including 44 patients (88%) with stage 3 or 4 ACC. VTEs were CTCAE grade ≤2 in 32 cases (59.3%), grade 3 in 17 (31.5%), and grade 4 in 2 (3.7%). Thirteen patients (24%) died within 6 months after VTE diagnosis, although there was no statistically significant association between VTE and overall survival.

CONCLUSION

Despite the potential to underestimate the prevalence of VTEs, we found a high frequency of VTE events in patients with ACC. A majority of VTEs occurred in the context of advanced ACC and we observed high short-term mortality. Further studies are needed to validate our findings and investigate mechanisms associated with VTE in ACC.

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

BACKGROUND

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.

PATIENTS AND METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Cabozantinib monotherapy for advanced adrenocortical carcinoma: a single-arm, phase 2 trial

BACKGROUND

Adrenocortical carcinoma is a rare malignancy with poor response to systemic chemotherapy. Mitotane is the only approved therapy for adrenocortical carcinoma. Cabozantinib is a multikinase inhibitor approved in multiple malignancies. This is the first prospective trial to explore the anti-tumour activity, safety, and pharmacokinetic profile of cabozantinib in patients with advanced adrenocortical carcinoma.

METHODS

This investigator-initiated, single-arm, phase 2 trial in adult patients (aged ≥18 years) with advanced adrenocortical carcinoma was done at the University of Texas MD Anderson Cancer Center (Houston, TX, USA). Eligible patients had histologically confirmed adrenocortical carcinoma, were not candidates for surgery with curative intent, had measurable disease, had an estimated life expectancy of at least 3 months, and an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2 with adequate organ function. Patients who had used mitotane within 6 months of study participation were required to have a serum mitotane level of less than 2 mg/L. Patients were given oral cabozantinib 60 mg daily with the option of dose reduction to manage adverse events. The primary endpoint was progression-free survival at 4 months, assessed in all patients who received at least one dose of study drug per protocol. This study is registered with ClinicalTrials.gov, NCT03370718, and is now complete.

FINDINGS

Between March 1, 2018, and May 31, 2021, we enrolled 18 patients (ten males and eight females), all of whom received at least one dose of study treatment. Of the 18 patients, eight (44%) had an ECOG performance status of 0, nine (50%) patients had a performance status of 1, and one (6%) patient had a performance status of 2. Median follow-up was 36·8 months (IQR 30·2-50·3). At 4 months, 13 (72·2%; 95% CI 46·5-90·3) of 18 patients had progression-free survival and median progression-free survival was 6 months (95% CI 4·3 to not reached). One patient remains on treatment. Treatment-related adverse events of grade 3 or worse occurred in 11 (61%) of 18 patients. The most common grade 3 adverse events were lipase elevation (three [17%] of 18 patients), elevated γ-glutamyl transferase concentrations (two [11%] patients), elevated alanine aminotransferase concentrations (two [11%] patients), hypophosphatemia (two [11%] patients), and hypertension (two [11%] patients). One (6%) of 18 patients had grade 4 hypertension. No treatment related deaths occurred on study.

INTERPRETATION

Cabozantinib in advanced adrenocortical carcinoma showed promising efficacy with a manageable and anticipated safety profile. Further prospective studies with cabozantinib alone and in combination with immune checkpoint therapy are ongoing.

FUNDING

Exelixis.

Cabozantinib in patients with unresectable and progressive metastatic phaeochromocytoma or paraganglioma (the Natalie Trial): a single-arm, phase 2 trial

BACKGROUND

Metastatic phaeochromocytomas and paragangliomas (MPPGs) are orphan diseases. Up to 50% of MPPGs are associated with germline pathogenic variants of the SDHB gene. These tumours and many non-familial MPPGs exhibit a phenotype that is characterised by abnormal angiogenesis. We aimed to assess the activity and safety of cabozantinib, an antiangiogenic multi-tyrosine kinase inhibitor, in patients with MPPGs.

METHODS

The Natalie Trial is a single-arm, phase 2 clinical trial being conducted at The University of Texas MD Anderson Cancer Center (Houston, TX, USA). Patients aged 18 years or older with histologically confirmed, progressive, and unresectable MPPGs, with an Eastern Cooperative Oncology Group performance status of 0-2, were treated with oral cabozantinib 60 mg/day. The primary endpoint was the investigator-assessed overall response rate per the Response Evaluation Criteria in Solid Tumours version 1.1 criteria. All outcomes were assessed in all evaluable participants who received any amount of study treatment. The trial is registered with ClinicalTrials.gov (NCT02302833) and is active but not recruiting.

FINDINGS

From March 10, 2015, to May 11, 2021, 17 patients (13 male participants and four female participants) were enrolled. The median follow-up was 25 months (IQR 18-49). The overall response rate was 25·0% (95% CI 7·3-52·4; four of 16 patients). Seven grade 3 adverse events were reported in six patients, including single cases of hand-and-foot syndrome, hypertension, rectal fistula, QT prolongation, and asymptomatic hypomagnesaemia, and two cases of asymptomatic elevations of amylase and lipase. There were no grade 4 adverse events and no patient died on-study.

INTERPRETATION

Cabozantinib shows promising activity in patients with MPPGs.

FUNDING

Team NAT Foundation, Margaret Cazalot, and Clarence P Cazalot.

Phase 1b Trial Evaluating Tolerability and Activity of Targeted Fibroblast Growth Factor Receptor Inhibition in Localized Upper Tract Urothelial Carcinoma

PURPOSE

We initiated a biomarker-informed preoperative study of infigratinib, a fibroblast growth factor receptor (FGFR) inhibitor, in patients with localized upper tract urothelial carcinoma (UTUC), a population with high unmet needs and tumor with a high frequency of FGFR3 alterations.

MATERIALS AND METHODS

Patients with localized UTUC undergoing ureteroscopy or nephroureterectomy/ureterectomy were enrolled on a phase 1b trial (NCT04228042). Once-daily infigratinib 125 mg by mouth × 21 days (28-day cycle) was given for 2 cycles. Tolerability was monitored by Bayesian design and predefined stopping boundaries. The primary endpoint was tolerability, and the secondary endpoint was objective response based on tumor mapping, done after endoscopic biopsy and post-trial surgery. Total planned enrollment: 20 patients. Targeted sequencing performed using a NovaSeq 6000 solid tumor panel.

RESULTS

From May 2021 to November 2022, 14 patients were enrolled, at which point the trial was closed due to termination of all infigratinib oncology trials. Two patients (14.3%) had treatment-terminating toxicities, well below the stopping threshold. Responses occurred in 6 (66.7%) of 9 patients with FGFR3 alterations. Responders had median tumor size reduction of 67%, with 3 of 5 patients initially planned for nephroureterectomy/ureterectomy converted to ureteroscopy. Median follow-up in responders was 24.7 months (14.9-28.9).

CONCLUSIONS

In this first trial of targeted therapy for localized UTUC, FGFR inhibition was well tolerated and had significant activity in FGFR3 altered tumors. Renal preservation was enabled in a substantial proportion of participants. These data support the design of a biomarker-driven phase 2 trial of FGFR3 inhibition in this population with significant unmet clinical needs.

Bone mimetic environments support engineering, propagation, and analysis of therapeutic response of patient-derived cells, ex vivo and in vivo

Bone metastases are the most common milestone in the lethal progression of prostate cancer and prominent in a substantial portion of renal malignancies. Interactions between cancer and bone host cells have emerged as drivers of both disease progression and therapeutic resistance. To best understand these central host-epithelial cell interactions, biologically relevant preclinical models are required. To achieve this goal, we here established and characterized tissue-engineered bone mimetic environments (BME) capable of supporting the growth of patient-derived xenograft (PDX) cells, ex vivo and in vivo. The BME consisted of a polycaprolactone (PCL) scaffold colonized by human mesenchymal stem cells (hMSCs) differentiated into osteoblasts. PDX-derived cells were isolated from bone metastatic prostate or renal tumors, engineered to express GFP or luciferase and seeded onto the BMEs. BMEs supported the growth and therapy response of PDX-derived cells, ex vivo. Additionally, BMEs survived after in vivo implantation and further sustained the growth of PDX-derived cells, their serial transplant, and their application to study the response to treatment. Taken together, this demonstrates the utility of BMEs in combination with patient-derived cells, both ex vivo and in vivo. STATEMENT OF SIGNIFICANCE: Our tissue-engineered BME supported the growth of patient-derived cells and proved useful to monitor the therapy response, both ex vivo and in vivo. This approach has the potential to enable co-clinical strategies to monitor bone metastatic tumor progression and therapy response, including identification and prioritization of new targets for patient treatment.

Cabozantinib in the Routine Management of Renal Cell Carcinoma: A Systematic Literature Review of Real-World Evidence

Real-world cabozantinib use has increased since its approval to treat patients with advanced renal cell carcinoma (RCC) in 2016. We reviewed cabozantinib use in real-world clinical practice and compared outcomes with pivotal cabozantinib randomized control trials (RCTs). This PRISMA-standard systematic literature review evaluated real-world effectiveness and tolerability of cabozantinib in patients with RCC (PROSPERO registration: CRD42021245854). Systematic MEDLINE, Embase, and Cochrane database searches were conducted on November 2, 2022. Eligible publications included ≥ 20 patients with RCC receiving cabozantinib. After double-screening for eligibility, standardized data were abstracted, qualitatively summarized, and assessed for risk of bias using the Newcastle-Ottawa Scale. Of 353 screened publications, 41 were included, representing approximately 11,000 real-world patients. Most publications reported cabozantinib monotherapy cohort studies (40/41) of retrospective (39/41) and multicenter (32/41) design; most included patients from North America and/or Europe (30/41). Baseline characteristics were demographically similar between real-world and pivotal RCT populations, but real-world populations showed greater variation in prevalence of prior nephrectomy, multiple-site/brain metastasis, and nonclear-cell RCC histology. Cabozantinib activity was reported across real-world treatment lines and tumor types. Overall survival, progression-free survival, and objective response rate values from pivotal RCTs were within the ranges reported for equivalent outcomes across real-world studies. Common real-world grade ≥ 3 adverse events were consistent with those in pivotal RCTs (fatigue, palmar-plantar erythrodysesthesia syndrome, diarrhea, hypertension), but less frequent. No new tolerability concerns were identified. Real-world RCC survival outcomes for cabozantinib monotherapy were broadly consistent with pivotal RCTs, despite greater heterogeneity in real-world populations.

Long-Term Oncological Outcomes in Patients Diagnosed With Nonmetastatic Plasmacytoid Variant of Bladder Cancer: A 20-Year University of Texas MD Anderson Cancer Center Experience

PURPOSE

The treated natural history of nonmetastatic plasmacytoid variant of bladder cancer (PV-BCa) is poorly understood owing to its rarity. We sought to examine the disease recurrence and metastasis patterns in this select group of patients in order to identify opportunities for intervention.

MATERIALS AND METHODS

We conducted a natural language processing algorithm-augmented retrospective chart review of 56 consecutive patients who were treated with curative intent for nonmetastatic PV-BCa at our institution between 1998 and 2018. Kaplan-Meier and multivariable Cox regression methods were used for survival analyses.

RESULTS

The stage at presentation was: ≤ cT2N0 in 22 (39.3%), cT3N0 in 15 (26.8%), cT4N0 in 13 (23.2%), and ≥ cN1 in 6 patients (10.7%). Forty-nine patients (87.5%) received chemotherapy, and 42 (75%) were able to undergo the planned surgery. Notably, only 4 patients (7.2%) had pT0 stage, while 22 (52.4%) had pN+ disease at the time of surgery. At 36-month follow-up, 28.4% of patients (95% CI: 22.1%-34.5%) were alive and 22.2% (95% CI: 16.1%-28.5%) were free of metastatic disease. The benefit of surgical extirpation was stage specific: successful completion of surgery was associated with improved metastasis-free survival (at 36 months 32.4% vs 0%, log-rank P < .001) in patients with localized or locally advanced disease (≤cT2N0/cT3N0); however, in patients with regionally advanced disease (cT4N0/≥cN1), consolidative surgery following chemotherapy was not associated with improved metastasis-free survival (12.5% vs 10% at 36 months, log-rank P = .49). The median time to metastasis from primary treatment end was 6.5 months (IQR: 2.9-14.7). The predominant site of recurrence/metastasis was the peritoneum (76.1%), either in isolation or along with extraperitoneal lesions. Salvage immunotherapy in these patients significantly reduced the risk of death (HR = 0.11, P = .001).

CONCLUSIONS

PV-BCa is a disease with high lethality. Despite multimodal treatment, a vast majority of patients develop atypical intraperitoneal metastasis soon after therapy and rapidly succumb to it. Clinical trials evaluating utility of hyperthermic intraperitoneal chemotherapy and/or immunotherapy may be warranted in this high-risk population.

Definitions, End Points, and Clinical Trial Designs for Bladder Cancer: Recommendations From the Society for Immunotherapy of Cancer and the International Bladder Cancer Group

PURPOSE

There is a significant unmet need for new and efficacious therapies in urothelial cancer (UC). To provide recommendations on appropriate clinical trial designs across disease settings in UC, the Society for Immunotherapy of Cancer (SITC) and the International Bladder Cancer Group (IBCG) convened a multidisciplinary, international consensus panel.

METHODS

Through open communication and scientific debate in small- and whole-group settings, surveying, and responses to clinical questionnaires, the consensus panel developed recommendations on optimal definitions of the disease state, end points, trial design, evaluations, sample size calculations, and pathology considerations for definitive studies in low- and intermediate-risk nonmuscle-invasive bladder cancer (NMIBC), high-risk NMIBC, muscle-invasive bladder cancer in the neoadjuvant and adjuvant settings, and metastatic UC. The expert panel also solicited input on the recommendations through presentations and public discussion during an open session at the 2021 Bladder Cancer Advocacy Network (BCAN) Think Tank (held virtually).

RESULTS

The consensus panel developed a set of stage-specific bladder cancer clinical trial design recommendations, which are summarized in the table that accompanies this text.

CONCLUSION

These recommendations developed by the SITC-IBCG Bladder Cancer Clinical Trial Design consensus panel will encourage uniformity among studies and facilitate drug development in this disease.

Comparative Effectiveness Analysis of Treatment Strategies for Surgically Resectable Neuroendocrine Carcinoma of the Urinary Tract

BACKGROUND

Neoadjuvant chemotherapy (neoCTX) has been recommended as the optimal strategy in surgically resectable neuroendocrine carcinoma (NEC) of the urinary tract (NEC-URO).

OBJECTIVE

To determine the systemic therapy regimen and timing, which are most active against NEC-URO.

DESIGN, SETTING, AND PARTICIPANTS

We used our institutional historical clinical and pathological database to study 203 patients (cT2, 74%; cT3/4a, 22%; and cTx, 4%) with surgically resectable NEC-URO between November 1985 and May 2020. A total of 141 patients received neoCTX and 62 underwent initial radical surgery, 24 of whom received adjuvant CTX (adjCTX).

INTERVENTION

Neoadjuvant CTX with etoposide/cisplatin (EP), an alternating doublet of ifosfamide/doxorubicin (IA) and EP, dose-dense methotrexate/vinblastine/doxorubicin/cisplatin (MVAC), gemcitabine/cisplatin (GC), or others.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Overall survival (OS), downstaging rate, and pathological complete response using a multivariable model adjusting for tumor- and patient-related factors.

RESULTS AND LIMITATIONS

Downstaging rate was significantly improved with neoCTX versus initial surgery (49.6% vs 14.5%, p < 0.0001), stage cT2N0 versus cT3/4N0 (44% vs 25%, p = 0.01), or presence of carcinoma in situ (47% vs 28%, p = 0.01). Downstaging was greatest with IA/EP (65%) versus EP (39%), MVAC/GC (27%), or others (36%, p = 0.04). After adjusting for age and Eastern Cooperative Oncology Group performance status, IA/EP was still associated with improved downstaging (odds ratio = 3.7 [1.3-10.2], p = 0.01). At a median follow-up of 59.7 mo, 5-yr OS rates for neoCTX followed by surgery, surgery alone, and surgery followed by adjCTX were 57%, 22%, and 30%, respectively. An NEC regimen (IA/EP or EP) versus a urothelial regimen (MVAC/GC or others) was associated with improved survival (145.4 vs 42.5 mo, hazard ratio = 0.49, 95% confidence interval: 0.25-0.94).

CONCLUSIONS

Neoadjuvant CTX remains the standard-of-care treatment for NEC-URO with an advantage for NEC regimens over traditional urothelial regimens. IA/EP improves pathological downstaging at the time of surgery compared with EP, but is reserved for younger and higher function patients.

PATIENT SUMMARY

In this report, we looked at the outcomes from invasive neuroendocrine carcinoma of the urinary tract in a large US population. We found that the outcomes varied with treatment strategy. We conclude that the best outcomes are seen in patients treated with chemotherapy prior to surgery and regimens tailored to histology and tolerance.

Special Issue Editorial: Emerging Therapies in Renal Cell Carcinoma: The Road to a Cure?

In the past two decades, therapy development in the treatment of renal cell carcinoma has exploded [...].

Cytoreductive Nephrectomy for Patients with Metastatic Sarcomatoid and/or Rhabdoid Renal Cell Carcinoma Treated with Immune Checkpoint Therapy

BACKGROUND

Renal cell carcinoma (RCC) with sarcomatoid and/or rhabdoid (S/R) dedifferentiation is a highly aggressive tumor with a poor prognosis. Immune checkpoint therapy (ICT) has shown significant treatment efficacy in this subtype. There remains uncertainly regarding the role of cytoreductive nephrectomy (CN) for patients with metastatic RCC (mRCC) with S/R who received ICT.

OBJECTIVE

Here, we report the outcomes with ICT for patients with mRCC and S/R dedifferentiation by CN status.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective review was conducted of 157 patients with sarcomatoid, rhabdoid, or sarcomatoid plus rhabdoid dedifferentiation who received an ICT-based regimen at two cancer centers.

INTERVENTION

CN performed at any time point; nephrectomy with curative intent was excluded.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

ICT treatment duration (TD) and overall survival (OS) from ICT initiation were recorded. To address the immortal time bias, a time-dependent Cox regression model was generated that accounted for confounders identified by a directed acyclic graph as well as a time-dependent nephrectomy variable.

RESULTS AND LIMITATIONS

A total of 118 patients underwent CN, and of them, 89 underwent upfront CN. The results did not contradict the supposition that CN does not improve ICT TD (hazard ratio [HR] 0.98, 95% confidence interval [CI] 0.65-1.47, p = 0.94) or OS from ICT initiation (HR 0.79, 95% CI 0.47-1.33, p = 0.37). In patients who underwent upfront CN compared with those who did not undergo CN, there was no association with ICT duration or OS (HR 0.61, 95% CI 0.35-1.06, p = 0.08). A detailed clinical summary of 49 patients with mRCC and rhabdoid dedifferentiation is provided.

CONCLUSIONS

In this multi-institutional cohort of mRCC with S/R dedifferentiation treated with ICT, CN was not significantly associated with improved TD or superior OS when accounting for the lead time bias. There appears to be a subset of patients who derive meaningful benefit from CN, so improved tools for stratification prior to CN are needed to optimize outcomes.

PATIENT SUMMARY

Immunotherapy has improved outcomes for patients with metastatic renal cell carcinoma (mRCC) who have sarcomatoid and/or rhabdoid (S/R) dedifferentiation, which is an aggressive and uncommon feature; yet, the utility of a nephrectomy in this setting is unclear. We found that nephrectomy did not significantly improve survival or time on immunotherapy for these patients with mRCC and S/R dedifferentiation; yet, there may be a subset of patients who benefit from this surgical approach.

Identifying the Needs of Health Care Providers in Advanced First-Line Renal Cell Carcinoma: A Mixed-Methods Research

INTRODUCTION

Systemic treatments for metastatic or unresectable renal cell carcinoma (mRCC) are rapidly evolving. This study aimed at investigating challenges in the care of mRCC to inform future educational interventions for health care providers (HCPs).

MATERIALS AND METHODS

The sequential mixed-method design consisted of a qualitative phase (semistructured interviews) followed by a quantitative phase (online surveys). Participants included US-based medical oncologists, nephrologists, physician assistants, nurse practitioners, and registered nurses. Interview transcripts were thematically analyzed. Survey data was descriptively and inferentially analyzed.

RESULTS

Forty interviews and 265 surveys were completed. Analysis revealed four challenges in the care of mRCC patients. A challenge in staying current with emerging evidence and treatment recommendations was found with 33% of surveyed HCPs reporting suboptimal skills interpreting published evidence on the efficacy and safety of emerging agents. A challenge weighing patient health and preferences in treatment decisions was found, especially among HCPs with 3 to 10 years of practice (37%) who reported suboptimal skills in assessing patients' tolerance to side effects. Promoting a collaborative care approach to the management of immune-related adverse events was a challenge, specifically related to barriers involving nephrologists (eg, diverging treatment goals). Breakdowns in communication were reported (46% of HCPs), especially in the monitoring of side effects and treatment adherence.

CONCLUSION

This study revealed key challenges faced by HCPs when treating and managing patients with mRCC across multiple providers. Future interventions (eg, community of practice) should aim to address the identified gaps and promote a team-based approach to care that strengthens the complementary competencies of HCPs involved.

Phase II trial of neoadjuvant sitravatinib plus nivolumab in patients undergoing nephrectomy for locally advanced clear cell renal cell carcinoma

Sitravatinib is an immunomodulatory tyrosine kinase inhibitor that can augment responses when combined with programmed death-1 inhibitors such as nivolumab. We report a single-arm, interventional, phase 2 study of neoadjuvant sitravatinib in combination with nivolumab in patients with locally advanced clear cell renal cell carcinoma (ccRCC) prior to curative nephrectomy (NCT03680521). The primary endpoint was objective response rate (ORR) prior to surgery with a null hypothesis ORR = 5% and the alternative hypothesis set at ORR = 30%. Secondary endpoints were safety; pharmacokinetics (PK) of sitravatinib; immune effects, including changes in programmed cell death-ligand 1 expression; time-to-surgery; and disease-free survival (DFS). Twenty patients were evaluable for safety and 17 for efficacy. The ORR was 11.8%, and 24-month DFS probability was 88·0% (95% CI 61.0 to 97.0). There were no grade 4/5 treatment-related adverse events. Sitravatinib PK did not change following the addition of nivolumab. Correlative blood and tissue analyses showed changes in the tumour microenvironment resulting in an immunologically active tumour by the time of surgery (median time-to-surgery: 50 days). The primary endpoint of this study was not met as short-term neoadjuvant sitravatinib and nivolumab did not substantially increase ORR.

Evolving systemic management of urothelial cancers

PURPOSE OF REVIEW

Bladder cancer is the 12th most common cancer worldwide. Historically, the systemic management of urothelial carcinoma has been confined to platinum-based chemotherapy. In this review, we discuss the evolving landscape of systemic treatment for urothelial carcinoma.

RECENT FINDINGS

Since 2016, when the Food and Drug Administration approved the first immune checkpoint inhibitor (CPI), programmed cell death 1 and programmed cell death ligand 1 inhibitors have been evaluated in the nonmuscle invasive bladder cancer, localized muscle invasive bladder cancer as well as advanced/metastatic bladder cancer settings. Newer approved treatments such as fibroblast growth factor receptor (FGFR) inhibitors and antibody-drug conjugates (ADCs) represent second-line and third-line options. These novel treatments are now being assessed in combination as well as with older traditional platinum-based chemotherapy.

SUMMARY

Novel therapies continue to improve bladder cancer outcomes. Personalized approach with well validated biomarkers are important to predict response to therapy.

Integrative Clinical and Genomic Characterization of MTAP-deficient Metastatic Urothelial Cancer

Deficiency of MTAP (MTAPdef) mainly occurs because of homozygous loss of chromosome 9p21, which is the most common copy-number loss in metastatic urothelial cancer (mUC). We characterized the clinical and genomic features of MTAPdef mUC in 193 patients treated at MD Anderson Cancer Center (MDACC) and 298 patients from the phase 2 IMvigor210 trial, which investigated atezolizumab in cisplatin-ineligible and platinum-refractory disease. In the MDACC cohort, visceral metastases were significantly more common for MTAPdef (n = 48) than for MTAP-proficient (MTAPprof; n = 145) patients (75% vs 55.2%; p = 0.02). MTAPdef was associated with poor prognosis (median overall survival [mOS] 12.3 vs 20.2 mo; p = 0.007) with an adjusted hazard ratio of 1.93 (95% confidence interval 1.35-2.98). Similarly, IMvigor210 patients with MTAPlo (n = 29) had a higher incidence of visceral metastases than those with MTAPhi tumors (n = 269; 86.2% vs 72.5%; p = 0.021) and worse prognosis (mOS 8.0 vs 11.3 mo; p = 0.042). Hyperplasia-associated genes were more frequently mutated in MTAPdef tumors (FGFR3: 31% vs 8%; PI3KCA: 31% vs 19%), while alterations in dysplasia-associated genes were less common in MTAPdef tumors (TP53: 41% vs 67%; RB1: 0% vs 16%). Our findings support a distinct biology in MTAPdef mUC that is associated with early visceral disease and worse prognosis. PATIENT SUMMARY: We investigated the outcomes for patients with the most common gene loss (MTAP gene) in metastatic cancer of the urinary tract. We found that this loss correlates with worse prognosis and a higher risk of metastasis in internal organs. There seems to be distinct tumor biology for urinary tract cancer with MTAP gene loss and this could be a potential target for treatment.

Phase 2 clinical study evaluating the efficacy and safety of disitamab vedotin with or without pembrolizumab in patients with HER2-expressing urothelial carcinoma (RC48G001)

TPS594

Background: Urothelial carcinoma (UC) is the 10th most diagnosed cancer worldwide, and nearly 50% of patients cannot tolerate the current first-line (1L) standard of care. There is a need to improve outcomes in 1L and later lines of therapy. HER2 is overexpressed in UC and may be associated with poor outcomes. Despite this, no HER2-directed therapies are currently approved for UC. Disitamab vedotin (DV; RC48-ADC) is an investigational antibody-drug conjugate comprising a novel HER2-directed monoclonal antibody, disitamab, conjugated to monomethyl auristatin E (MMAE) via a protease-cleavable mc-vc linker. DV elicits antitumor activity through multimodal mechanisms of action including MMAE-mediated direct cytotoxicity, bystander effect, and immunogenic cell death. Methods: RC48G001 (NCT04879329) is a phase 2, multi-cohort, open-label, multicenter trial to evaluate DV in patients with HER2-expressing locally advanced/metastatic UC (LA/mUC). Patients are enrolled in 3 cohorts based on prior treatment and tumor HER2 expression by immunohistochemistry (IHC) and gene amplification (via in situ hybridization [ISH]), assessed centrally. Cohorts A and B are enrolling patients who have received prior systemic therapy (1 or 2 lines, including platinum-containing chemotherapy) and whose tumors are HER2-positive (IHC 3+, or 2+ and ISH-positive) or HER2-low (IHC 2+ and ISH-negative, or IHC 1+), respectively. Cohort C is enrolling 1L treatment-naive patients in the LA/mUC setting, whose tumors have HER2-positive or HER2-low expression. Cohorts A and B will evaluate DV as monotherapy (intravenous [IV] administration, once every 2 weeks [Q2W]). Cohort C will evaluate DV (IV, Q2W) +/– pembrolizumab (IV, Day 1 of each 6-week cycle). Patients in all cohorts must have measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 and an Eastern Cooperative Oncology Group Performance Status of 0–1 in Cohorts A and B, and 0–2 in Cohort C. The primary endpoint is confirmed objective response rate (cORR) per blinded independent central review (BICR). Secondary endpoints include cORR by investigator assessment, overall survival, duration of response, progression-free survival, disease control rate per RECIST v1.1 by BICR and investigator, safety, and pharmacokinetic parameters. Enrollment for all cohorts is ongoing in North America and Europe, and planned in Latin America, Asia-Pacific, and Israel. Clinical trial information: NCT04879329 .

Biomarkers of response to enfortumab vedotin (EV) in patients (pts) with advanced urothelial carcinoma (aUC): Analysis of the UNITE study

450

Background: EV, an antibody-drug conjugate (ADC) targeting Nectin-4, is used widely in treatment-refractory aUC, but limited data are available on biomarkers predictive of EV outcomes. We investigated potential biomarkers of response to EV in a pt cohort in the UNITE dataset. Methods: We included the retrospective UNITE study pts from 16 sites, with available next generation sequencing using institutional or commercial platforms, treated with EV alone outside clinical trials. Observed response (ORR) was determined by investigators for evaluable pts with scans after ≥1 dose of EV. Assessed molecular biomarkers included tumor mutation burden (TMB), PD-L1 status, somatic alterations (alts) in ≥ 10% of pts ( TERTp, TP53, ARID1A, CDKN2A, CDKN2B, FGFR3, ERBB2, CCND1, KDM6A, MTAP, PIK3CA, RB1, TSC1) and presence of ≥1 DNA damage response mutations ( ATM, BARD1, BRCA1, BRCA2, CDK12, CHEK2, PALB2, PPP2R2A, or RAD51B). ORRs were compared using Chi-squared test, while median progression-free and overall survival (mPFS, mOS) from EV start were compared with log-rank test and Cox proportional hazards in pts with and without biomarker presence. Results: A total of 170 pts had outcomes and NGS data available. Median age was 70, 133 (78%) were men, 144 (85%) Caucasian, 110 (65%) with pure urothelial histology, 118 (69%) with primary bladder tumor, and 116 (68%) had ≥ 2 lines of therapy before EV. For all pts, ORR 47%, mPFS 6 mos, mOS 12 mos. ORRs were higher in pts with ERBB2 (67% vs 44%; p = 0.05) and TSC1 (68% vs 25%; p=0.04) alts vs wild-type. Shorter mPFS was noted in pts with CDKN2A, CDKN2B, and MTAP alts, and longer mOS in pts with high TMB (table). Conclusions: This large, multi-site, retrospective cohort of pts with aUC identified several potential biomarkers associated with differential outcomes to EV. These findings, upon external validation, may help inform clinical decision making and potential therapy sequencing with available ADCs. Limitations include retrospective nature, pt selection, and confounding biases. [Table: see text]

A phase 1b/2 study of batiraxcept (AVB-S6-500) in combination with cabozantinib in patients with advanced or metastatic clear cell renal cell carcinoma (ccRCC)

666

Background: Activation of the GAS6/AXL pathway promotes tumor cell proliferation; high levels of GAS6 and AXL have been associated with drug resistance and decreased survival. Batiraxcept is an ultra-high affinity decoy protein that captures GAS6, preventing it from activating AXL signaling. Serum soluble AXL (sAXL)/GAS6 ratio correlates with response to batiraxcept in advanced ovarian cancer. Batiraxcept in combination with cabozantinib is being evaluated in patients (pts) with metastatic clear cell renal cell carcinoma (ccRCC) in this study. Prior studies of cabozantinib in similar pt populations have shown an overall response rate (ORR) ranging from 15 – 32.5% and progression-free survival (PFS) from 3.7-7.2 months (mo). Methods: Key eligibility criteria include previously treated ccRCC pts, excluding prior cabozantinib. Objectives were to determine the safety of batiraxcept plus cabozantinib 60 mg, the recommended phase 2 dose (RP2D), ORR, PFS, duration of response. Correlative endpoints included assessment of baseline serum sAXL/GAS6 with ORR and PFS. Results: In Phase 1b (P1b), 26 pts received at least one dose of batiraxcept with cabozantinib (16 pts - 15 mg/kg; 10 pts - 20 mg/kg). Median age was 60 (range 40-81), male 85% (n=22), IMDC intermediate/poor risk 77% (n=20). All pts received prior immuno-oncology (IO) therapy, 54% (n=14) also received VEGF-TKI; 85% (n=22) received 1 to 2 prior lines of therapy (range 1-6). Median follow-up time was 11.6 mo (range 3.7-18). The RP2D is 15 mg/kg. Related adverse events (AE) any grade and grade ≥ 3 were 100% and 39% (n=10), respectively. Cabozantinib dose reductions occurred in 54% (n=14). AEs of special interest were grade 1 or 2 infusion related reactions, 27% (n=7). Batiraxcept was discontinued due to disease progression 62% (n=16) or toxicity 12% (n=3). The table shows P1b efficacy, ORR of 42%, median PFS of 9.3 mo, and DCR of 84%. Twenty (77%) pts had high baseline sAXL/GAS6 levels; ORR was 55% (11/20) with mPFS of 9.3 mo, compared to 0% ORR and mPFS 6.4 mo in the low sAXL/GAS6 pts. Conclusions: Batiraxcept was well tolerated when combined with cabozantinib. No new safety signals were noted. Efficacy for the combination is encouraging compared to historical cabozantinib monotherapy data. Higher GAS6 levels were predictive for treatment response. The P2 accrual is complete and efficacy data are maturing. A P3 trial plans to evaluate the efficacy in ccRCC patients who have progressed on IO-based and VEGF-TKI therapies. Clinical trial information: NCT04300140 . [Table: see text]

Enfortumab vedotin (EV) outcomes with and without immediate prior immune checkpoint inhibitor (ICI) in patients (pts) with advanced urothelial carcinoma (aUC)

514

Background: EV is FDA-approved in pts with aUC and ≥1 prior therapy line. Data from EV-103 trial indicate robust response to first-line EV/pembrolizumab, suggesting potentially at least additive treatment effect with EV/ICI combination. Given the long half-life of ICIs, pts who start EV treatment immediately after ICI may potentially derive benefit from that therapy sequence. We hypothesized that the last systemic therapy prior to EV would impact outcomes, as pts treated with ICI immediately prior to EV would have superior outcomes relative to pts treated with chemotherapy (chemo). Methods: UNITE is a retrospective study of pts treated with EV at 16 US sites. Pt characteristics and outcomes were abstracted from EMR review at each site. Observed response was determined by investigators for evaluable pts with scans following ≥1 EV dose. Pts treated with EV monotherapy were divided into two groups based on whether they received chemo or ICI as the line of therapy immediately prior to EV, regardless of other therapy received. Chi-squared test was used to assess differences in pt characteristics and ORR while log-rank tests were used for OS and PFS measured from EV start. Results: Among 325 pts treated with EV monotherapy, 247 had chemo or ICI as immediate prior treatment, with 186 pts receiving ICI (Group A) and 61 pts receiving platinum-based chemo (Group B). In 247-pt cohort, ORR to EV was 52% and mPFS and mOS were 6 and 13 mos. Group B pts were younger, had more bone mets and higher Bellmunt risk factors, but were otherwise similar to Group A (Table). Most pts had both prior chemo and ICI in both group A (58%) and group B (84%). Group A pts had shorter time from last treatment (median 1.2 vs 3.2 mo, p<0.01), lower ORR to immediate prior treatment (16% vs 37%, p<0.01) and fewer prior therapy lines (mean 1.9 vs 2.6, p<0.01). Group A had superior ORR (58% vs 37%, p=0.02), mPFS (6.9 vs 4.8 mo, p=0.02) and mOS (15.2 vs 8.8 mo, p=0.01) from EV start vs Group B. Conclusions: Pts with aUC treated with EV had superior outcomes if they received ICI instead of chemo as immediate prior treatment, suggesting the hypothesis that this may represent an optimal therapy sequence or combination. These data need external validation as limitations include retrospective design, lack of randomization, and selection and confounding biases. [Table: see text]

A phase II study of nivolumab with ipilimumab and cabozantinib in patients with untreated renal cell carcinoma brain metastases

TPS745

Background: A SEER analysis from 2010 to 2013 demonstrated that the incidence of brain metastases(mets) at the diagnosis of renal cell carcinoma(RCC) is 1.51%, and around 12% of patients(pts) with advanced RCC (aRCC) also had mets to the brain. Brain mets confer a poor prognosis. Local management strategies for brain mets from RCC include surgical resection, stereotactic radiosurgery and whole brain radiation therapy. Although systemic therapies including tyrosine kinase inhibitors and immune checkpoint inhibitors have been explored in aRCC pts with brain mets, prospective data is lacking. Cabozantinib is a potent small molecule inhibitor of multiple tyrosine kinases that was approved by FDA for pts with aRCC alone or in combination with nivolumab. Cabozantinib has demonstrated activity in patients with intracranial tumors. A phase III trial (COSMIC-313) recently evaluated cabozantinib in combination with nivolumab and ipilimumab compared to nivolumab plus ipilimumab and demonstrated significantly improved progression-free survival (PFS) in previously untreated pts with aRCC. The combination was found to be safe as frontline systemic treatment. The role of this combination in patients with aRCC with brain mets remains undefined. As such, we propose a study to assess the safety and efficacy of cabozantinib in combination with nivolumab/ipilimumab in RCC pts with untreated brain mets. We believe the results from this trial could provide additional treatment options for pts with RCC brain mets who are typically excluded from clinical trials. Methods: This is a phase II study to assess the safety and efficacy of the combination of nivolumab with ipilimumab and cabozantinib in pts with untreated brain mets from RCC until disease progression or intolerable toxicities or patient withdrawal. Planned accrual is 40 pts. Pts will be treated with nivolumab (3mg/kg) and ipilimumab (1mg/kg) IV every 3 weeks for 4 doses and cabozantinib 40mg daily. Then pts will be treated with nivolumab 480mg IV Q 4 weeks and cabozantinib 40mg daily until progression or intolerable toxicities or patient’s withdrawal. A lead-in group of 6 pts will be closely monitored for dose limiting toxicities(DLT). If stopping criteria (>3 patients develop DLTs) is met, then treatment will be switched to nivolumab plus cabozantinib omitting ipilimumab. The primary objective is intracranial progression free survival(PFS). Secondary objectives include intracranial safety, objective response rate (intracranial + extracranial) by modified RECIST v1.1 and RECIST v1.1, extracranial PFS and overall survival. This phase II trial is currently enrolling pts. Clinical trial information: NCT05048212 .

Competing mortality risk from second primary malignancy in bladder cancer patients following radical cystectomy: Implications for survivorship

INTRODUCTION

Muscle-invasive bladder cancer (BC) often occurs in patients with competing mortality risks, while also being associated with the highest rate of second primary nonurothelial cancers (SNUC) of all solid malignancies. We investigated the incidence, risk factors, and timing of SNUC as a competing mortality risk factor in patients with BC who were treated with curative intent radical cystectomy (RC).

METHODS

We performed a retrospective cohort study assessing patients who underwent RC for cT2-4 N0M0 BC from January 1, 2005 to December 31, 2018 at a single, high volume tertiary care referral center. The Fine-Gray multivariable regression model was used to evaluate predictive factors for SNUC. Cumulative incidence of mortality (CIM) was estimated with modified Kaplan-Meier analysis.

RESULTS

The median follow-up time for the 693 patients who underwent RC was 3.7 years (interquartile range [IQR] 1.9-5.9 years). SNUC developed in 85 (12.3%) patients at a median 3.0 years post-RC (IQR 1.2-5.5 years). On multivariable analysis, the only significant predictor for developing SNUC was freedom from BC recurrence or metastasis (HR 1.54, 95% CI 1.12-1.76, P = 0.019). The most common SNUCs were primary lung cancer (24, 3.2% of cohort) and colon cancer (9, 1.3% of cohort). BC surveillance imaging diagnosed SNUC in 35/52 (67.3%) patients with solid-organ visceral primaries. The overall mortality rate for any SNUC was 38.8%, with the 3 most lethal cancer types being pancreatic, lung, and colon (62.5%, 54.2%, and 44.4% mortality, respectively). The incidence of SNUC uniformly increased postoperatively, with a cumulative incidence of 22.1% (95% CI, 16.8-27.9%) at 12-years post-RC. 163 patients (23.5%) died from BC, 33 patients (4.8%) died from SNUC, and 94 patients (13.6%) died from other causes. While the CIM for BC plateaued around 5-years post-RC at 24%, the incidence of other-cause mortality uniformly rose throughout the postoperative period. By post-RC year 9 there was no significant difference in CIM between BC (CIM 27.2%, 95% CI, 23.5-31.1%) and other-causes (CIM 20.0%, 95% CI, 15.8-24.6%).

CONCLUSIONS

The cumulative incidence of SNUC at 12-years post-RC was 22%, with the majority identified on BC surveillance imaging. While BC mortality plateaued around 5-years post-RC, mortality related to SNUC or other causes rose steadily in the postoperative period. These data have clinical significance with regards to patient counseling, survivorship and oncologic surveillance in the highly comorbid muscle-invasive BC population.

A phase 1b/2 study of batiraxcept (AVB-S6-500) in combination with cabozantinib, cabozantinib and nivolumab, and as monotherapy in patients with advanced or metastatic clear cell renal cell carcinoma (NCT04300140)

TPS4599

Background: In clear cell renal cell carcinoma (ccRCC) the constitutive expression of hypoxia induced factor 1-α leads to increased expression of AXL. AXL overexpression has been associated with the development of resistance to VEGF inhibitors and suppression of the innate immune response through inhibition of macrophage-driven inflammation. Batiraxcept is a recombinant fusion protein dimer containing an extracellular region of human AXL combined with the human immunoglobulin G1 heavy chain (Fc), which demonstrates highly potent, specific AXL inhibition. In preclinical studies using the 786-O, M62, and SN12L1 tumors, batiraxcept monotherapy resulted in a significant reduction of tumor growth compared to control. In healthy volunteer and ovarian cancer clinical studies, batiraxcept was well tolerated with no dose-related adverse events, and a maximum tolerated dose was not reached. Therefore, batiraxcept could be tested as either a monotherapy or in combination with standard of care drugs in patients with metastatic ccRCC. The Phase 1b dose-escalation portion of this study evaluated batiraxcept in combination with standard of care cabozantanib in patients who progressed on or after first line therapy. No DLT was observed at either of two batiraxcept doses evaluated. The recommended Phase 2 dose of batiraxcept has been identified as 15 mg/kg every 2 weeks (q2w) with cabozantinib 60 mg based upon safety, PK/PD, and preliminary efficacy data. Methods: This Phase 2, multi-center, open-label study includes three parts: Part A) batiraxcept 15 mg/kg q2w in combination with cabozantinib 60 mg daily for ccRCC subjects who have progressed on or after one line of therapy, n=25. Part B) batiraxcept 15 mg/kg q2w with cabozantinib 40 mg daily and nivolumab at the investigator’s choice (240 mg q2w or 480 mg q4w) for first line treatment of advanced or metastatic ccRCC subjects, n=20. If no safety signals are observed in the first 6 subjects enrolled, 10 subjects will be enrolled in the first stage of a Simon 2-stage minmax statistical design. If ≥ 6/10 subjects achieve PR or CR, stage 2 will open to enroll up to 20 total subjects. Part C) batiraxcept 15 mg/kg q2w monotherapy for subjects with advanced/metastatic ccRCC ineligible for curative intent therapies, n=10. The primary objective for each arm is objective response rate by RECIST v1.1. Secondary objectives include safety, duration of response, clinical benefit rate, progression free survival by RECIST v1.1, and overall survival. Exploratory objectives include pharmacokinetic and pharmacodynamic assessments. The Phase 2 portion of this Ph1b/2 study is currently enrolling. Clinical trial information: NCT04300140.

A phase 1b/2 study of batiraxcept (AVB-S6-500) in combination with cabozantinib in patients with advanced or metastatic clear cell renal cell (ccRCC) carcinoma who have received front-line treatment (NCT04300140)

4511

Background: AXL is up-regulated by hypoxia-inducible factor-1 signaling in both VHL-deficient and hypoxic tumor cells and plays a critical role in the metastatic phenotype of ccRCC. Batiraxcept is a recombinant fusion protein containing an extracellular region of human AXL combined with the human immunoglobulin G1 heavy chain (Fc), demonstrating highly potent, specific AXL inhibition. Methods: Batiraxcept at doses of 15 and 20 mg/kg, plus cabozantinib 60 mg daily, was evaluated using a 3+3 dose escalation study design. The primary objective was safety; secondary and exploratory objectives included identification of the recommended phase 2 dose (RP2D), overall response rate (ORR), and duration of response (DOR). Correlation of serum soluble AXL (sAXL)/GAS6 with ORR was evaluated. Key eligibility criteria include previously treated (2L+) ccRCC patients; prior treatment with cabozantanib was not allowed. sAXL/GAS6 was evaluated at baseline. Results: Data as of 4-February-2022, Phase 1b enrolled 26 patients, 16 patients treated with 15 mg/kg and 10 patients with 20 mg/kg dose of batiraxcept. Baseline characteristics: median age 60 (40-81); male 22 (85%); median prior line of therapy 1 (1-5); IMDC risk group of favorable 6 (23%); prior VEGF inhibitor 15 (58%); 100% with prior immunotherapy. At median follow up of 4.9 months, 92% (n=24) patients remained on the study. No dose limiting toxicities were observed at either 15 mg/kg or 20 mg/kg dose. Batiraxcept and cabozantinib related adverse events (AEs) occurred in 17 subjects (65%). Most common related AE include decreased appetite 31% (n=8), diarrhea and fatigue 23% (n=6). Grade 3 related AEs occurred in 4 patients (15%) including diarrhea, thromboembolism, hypertension, small bowel obstruction, and thrombocytopenia (n=1, 4% each) being most common. No grade 4 or 5 related AEs were observed. The ORR was 46% (n=12, partial response [PR]; Table). No patients had primary progressive disease. Among the patients who had baseline sAXL/GAS6 ratio of ≥ 2.3, the ORR was 67% (12/18). Regardless of baseline sAXL/GAS6 ratio, 3-month DOR was 100%; and 6-month progression free survival was 79%. Batiraxcept PK levels were similar across both doses and GAS6 levels suppressed through the dosing period. Conclusions: Batiraxcept plus cabozantinib is well tolerated. The RP2D of batiraxcept was identified as 15 mg/kg. Early efficacy signals were observed including 100% DOR at 3 months. Baseline sAXL/GAS6 may serve as a potential biomarker to enrich the population. Clinical trial information: NCT04300140. [Table: see text]

A phase II trial evaluating combination pemetrexed and avelumab in patients with MTAP-deficient advanced urothelial cancer

TPS4612

Background: MTAP-deficiency occurs primarily due to homozygous loss in chromosome 9p21 and is seen in approximately 25% of urothelial cancers. MTAP-deficiency portends aggressive biology with poorer outcomes than in MTAP-proficient tumors; for example, in the IMvigor210 data, MTAP-deficient patients had median overall survival of 8.0 months, compared to 11.3 months in MTAP-proficient patients (p = 0.042). MTAP-deficient tumors lack salvage nucleotide synthesis pathways and thus are uniquely sensitive to anti-folate agents; however, in prior clinical work with pemetrexed in these tumors, responses are relatively short-lived. In-vivo data has suggested that pemetrexed can increase tumor infiltrating T-cells, macrophages, dendritic cells, and PD-L1 expression in MTAP-deficient tumors and decrease myeloid-derived suppressor cells (MDSCs). As such, it was postulated that sequential treatment with anti-folate chemotherapy (pemetrexed) and immune checkpoint inhibition (avelumab) would improve responses in MTAP-deficient urothelial cancer. Methods: A prospective phase II trial of patients with advanced MTAP-deficient urothelial cancer is being conducted under IRB-approved protocol NCT03744793. This study will enroll 25 patients at a single site (The University of TX, MD Anderson Cancer Center). Key eligibility criteria include patients with advanced MTAP-deficient urothelial cancer with measurable disease in second-line or beyond. MTAP-deficiency is confirmed with CLIA-approved IHC or NGS. Patients are stratified as being IO-pretreated versus IO-naïve. All patients receive a lead-in cycle of pemetrexed (500 mg/m2) followed by combination pemetrexed (500 mg/m2) and avelumab (10 mg/kg) IV every three weeks until disease progression, patient withdrawal, or unacceptable toxicity. Three biopsies per patient with tissue collection at trial baseline, on single agent pemetrexed, and on combination pemetrexed-avelumab are performed. The primary objective of this trial is to evaluate response rate with sequential pemetrexed and avelumab in MTAP-deficient urothelial cancer. Imaging response assessment is done via RECIST v1.1. Secondary objectives are to evaluate progression-free survival (PFS) and overall survival (OS), as well as to perform correlative studies evaluating the effect of this therapy on immune cells and tumor microenvironment. This correlative work includes but is not limited to evaluation of peripheral T-cells, tumor-infiltrating T-cells, macrophages, and MDSCs. Interim analyses for futility and safety occur in cohorts of 5 patients and are performed based on Bayesian sequential methods. Fifteen patients have been enrolled thus far. Clinical trial information: NCT03744793.

A phase 1-2 trial of sitravatinib and nivolumab in clear cell renal cell carcinoma following progression on antiangiogenic therapy

The accumulation of immune-suppressive myeloid cells is a critical determinant of resistance to anti-programmed death-1 (PD-1) therapy in advanced clear cell renal cell carcinoma (ccRCC). In preclinical models, the tyrosine kinase inhibitor sitravatinib enhanced responses to anti-PD-1 therapy by modulating immune-suppressive myeloid cells. We conducted a phase 1-2 trial to choose an optimal sitravatinib dose combined with a fixed dose of nivolumab in 42 immunotherapy-naïve patients with ccRCC refractory to prior antiangiogenic therapies. The combination demonstrated no unexpected toxicities and achieved an objective response rate of 35.7% and a median progression-free survival of 11.7 months, with 80.1% of patients alive after a median follow-up of 18.7 months. Baseline peripheral blood neutrophil-to-lymphocyte ratio correlated with response to sitravatinib and nivolumab. Patients with liver metastases showed durable responses comparable to patients without liver metastases. In addition, correlative studies demonstrated reduction of immune-suppressive myeloid cells in the periphery and tumor microenvironment following sitravatinib treatment. This study provides a rationally designed combinatorial strategy to improve outcomes of anti-PD-1 therapy in advanced ccRCC.

Temporal Trends in Outcomes in Patients With Adrenocortical Carcinoma: A Multidisciplinary Referral-center Experience

CONTEXT

Reporting temporal trends in adrenocortical carcinoma (ACC) helps guide management strategies.

OBJECTIVE

This work aimed to report the trends in disease burden and clinical outcomes over time that cannot be adequately captured from individual clinical trials.

METHODS

A retrospective study was held of ACC patients seen at a referral cancer center between February 1998 and August 2019. Clinical outcomes were compared between an early cohort (February 1998-June 2007) and a late cohort (July 2007-August 2019).

RESULTS

A total of 621 patients included with a median age at diagnosis of 49.3 years (range, 0.5-86.6 years). There were 285 (45.9%) patients with hormonal overproduction. More patients in the late cohort had stage IV disease compared to the early cohort (36.8% vs 23.1%; P < .0001). Resection of the primary tumor was performed in 502 patients (80.8%). Complete resection (R0) was more common in the late cohort (165 [60.2%]) than in the early cohort (100 [44.6%]; P = .0005). Of 475 patients with metastatic disease (stage IV or recurrent metastatic disease), 352 (74.1%) received mitotane, 320 (67.4%) received chemotherapy, and 53 (11.2%) received immunotherapy. In the early cohort, 70 (33%) received 2 or more lines of therapy, whereas in the late cohort, 127 (48%) received 2 or more lines of therapy. The 5-year overall survival (OS) rates were 65%, 58%, 45%, and 10% for stage I, II, III, and IV disease, respectively, whereas the 2-year OS rates in patients with stage IV disease was 24% in the early cohort and 46% in the late cohort (P = .01).

CONCLUSION

ACC clinical outcomes improved over the past 2 decades as more patients had complete resection or received more lines of systemic therapy.

MTAP deficiency creates an exploitable target for antifolate therapy in 9p21-loss cancers

Methylthioadenosine phosphorylase, an essential enzyme for the adenine salvage pathway, is often deficient (MTAPdef) in tumors with 9p21 loss and hypothetically renders tumors susceptible to synthetic lethality by antifolates targeting de novo purine synthesis. Here we report our single arm phase II trial (NCT02693717) that assesses pemetrexed in MTAPdef urothelial carcinoma (UC) with the primary endpoint of overall response rate (ORR). Three of 7 enrolled MTAPdef patients show response to pemetrexed (ORR 43%). Furthermore, a historic cohort shows 4 of 4 MTAPdef patients respond to pemetrexed as compared to 1 of 10 MTAP-proficient patients. In vitro and in vivo preclinical data using UC cell lines demonstrate increased sensitivity to pemetrexed by inducing DNA damage, and distorting nucleotide pools. In addition, MTAP-knockdown increases sensitivity to pemetrexed. Furthermore, in a lung adenocarcinoma retrospective cohort (N = 72) from the published BATTLE2 clinical trial (NCT01248247), MTAPdef associates with an improved response rate to pemetrexed. Our data demonstrate a synthetic lethal interaction between MTAPdef and de novo purine inhibition, which represents a promising therapeutic strategy for larger prospective trials.

Very Late Recurrence in Germ Cell Tumor of the Testis: Lessons and Implications

Background. Very late recurrence (LR), i.e., >5 years after initial presentation, occurs in about 1% of patients with germ cell tumors of the testis (TGCT) and is associated with poor prognosis. Methods. We retrospectively reviewed the records of patients at the M. D. Anderson Cancer Center who developed LR > 5 years after their initial diagnosis of TGCT. Results. We identified 25 patients who developed LR between July 2007 and August 2020. The median age at the time of LR was 46 years (range, 29−61). Pathology of LR: somatic transformation to carcinoma or sarcoma—11, nonseminoma with yolk sac tumor or teratoma—11, nonseminoma without yolk sac tumor or teratoma—2, not available—1. With a median follow-up of 3.5 years, 68% of patients are alive 3 years after LR. Patients with prior post-chemotherapy consolidation surgery do not have statistically significant longer survival compared to patients who did not receive post-chemotherapy consolidation surgery, 83.3% vs. 60.8% at 3 years, respectively, p = 0.50. Conclusions. Patients with LR > 5 years tend to harbor nonseminoma (with yolk sac tumor and or teratoma). Among these patients, a majority who did not undergo surgery to remove residual disease after chemotherapy developed somatic transformation and succumbed to their LR.

Factors associated with improved outcomes in surgically resectable small cell urothelial cancer (SCUC)

495

Background: We have established that neoadjuvant (neo) chemotherapy (CTX) is the optimal strategy in localized SCUC given the frequent under staging. We have also demonstrated that alternating ifosfamide/doxorubicin (IA) and etoposide/cisplatin (EP) are active against SCUC; however, the optimal regimen has not been defined. Methods: We reviewed the records of 410 patients with SCUC treated at our institution between 1985 and 2020. Fisher’s exact test and logistic regression were used to determine the association between pathological complete response (pCR) and management approach. The Kaplan-Meier method was used to estimate overall survival (OS) from time of SCUC diagnosis to death or last follow up. Log rank test and Cox proportional models were used to determine the hazard-ratio (HR) between OS and management approach. Results: We included 203 patients with cT2-4aN0M0 SCUC who underwent cystectomy either after neoCTX (141, 69%), alone (38, 19%), or followed by adjuvant CTX (24, 12%). Clinical stage was cT2N0 (151, 74%), cT3/4N0 (44, 22%), or cTxN0 (8, 4%). Median age at diagnosis of SCUC was 66.7, 65.7, and 62.3 (p = 0.1) in the neoCTX, surgery alone and adjuvant CTX groups, respectively. Mean (+/- standard deviation) baseline glomerular filtration rate (GFR) was 75.6 (+/- 19.5), 61.3 (+/- 18.7), 70.5 (+/- 30.1) (p = 0.002) in the neoCTX, surgery alone and adjuvant CTX groups, respectively. Downstaging was significantly improved with neoCTX vs initial surgery (49.6% vs 14.5%, p <.0001), stage cT2N0 vs cT3/4N0 (44% vs 25%, p = 0.01), presence of carcinoma-in-situ (47% vs 28%, p = 0.01), or higher GFR (OR = 1.02, p = 0.06). In a multi-variable analysis of these factors, neoCTX was the only factor associated with pCR [OR = 3.9 (1.6-9.6) p = 0.003]. When comparing neoCTX regimens, downstaging was greatest with IA/EP (65%) as compared to EP (39%), MVAC/Gem/Cis (27%) or others (36%), p = 0.04. IA/EP was associated with younger age and good ECOG PS. In a multi-variable analysis of these factors, only IA/EP was associated with downstaging [OR = 3.7 (1.3-10.2), p = 0.01] and cT3/4 trended toward negatively impacting downstaging [OR = 0.5 (0.15-1.57), p = 0.23]. In the survival analysis, neoCTX, T2 vs T3/4, predominant small cell histology, good ECOG PS, higher GFR, and younger age were all significantly associated with improved outcomes. The best survival outcomes were observed with IA/EP (5-yr OS 64.2%), as compared to EP (5-yr OS 55.6%), MVAC/Gem/Cis (5-yr OS 50%) or others (5-yr OS 46.4%), p = 0.06, although these findings did not achieve statistical significance. Conclusions: NeoCTX remains the standard of care treatment for SCUC. The best downstaging was observed with IA/EP with a trend toward improved overall survival. We recommend the use of IA/EP whenever possible and consider EP for patients who are not able to tolerate ifosfamide.

Initial results of a phase II study of nivolumab(N) and ipilimumab(I) in genitourinary malignancies with neuroendocrine differentiation

569

Background: Patients with metastatic genitourinary malignancies with neuroendocrine have limited therapeutic options following platinum therapy. Given encouraging results in initial cohort analysis for small cell urinary tract carcinoma, a cohort of any genitourinary malignancy with neuroendocrine differentiation was added to a multicenter, single arm, multi-cohort phase II trial to evaluate the efficacy of N and I in this setting. (NCT 03333616) Methods: Eligible patients had metastatic or locally advanced genitourinary malignancy with neuroendocrine differentiation with an ECOG performance status of 0-2; they may have received any line of prior therapy excluding prior immunotherapy. Patients underwent baseline biopsy and received treatment with N 3 mg/kg and I 1 mg/kg intravenously every 3 weeks for 4 cycles with continued maintenance of N 480 mg IV every 4 weeks. Imaging was performed at 12 weeks and then every 8 weeks through month 6 and then every 12 weeks thereafter. The primary endpoint was investigator assessed objective response rate (ORR) by RECIST 1.1. Results: A total of 27 patients were enrolled between 06/27/2018 and 06/21/2021, 10 (37%) had urinary tract cancer and 17 (63%) had prostate cancer (19 in expansion cohort, 3 urinary tract and 5 prostate cancer from earlier cohorts). The majority (n=25, 93%) patients received prior systemic therapy. Nine (33%) patients received all 4 doses of N and I during the induction period. Nine (33%) patients (7 of whom received 4 cycles N+I) received N maintenance (median number of cycles 9 (range, 2-37)). Median follow-up was 6.8 (range, 0.9-37.3) months. Objective response was achieved in 8 (30%, 80% CI 18%-44%) patients (Table). Median duration of response was not reached with 4 patients maintaining response >9 months. Median progression-free survival time was 2.6 (95% CI 1.8-6.5) months At time of analysis, 13 (48%) death events were reported due to progressive disease, in which 3 were bladder and 10 were prostate cancer. 8 (30%) patients developed treatment-related grade 3 or higher toxicities; one grade 5 toxicity was deemed treatment-unrelated. Conclusions: In this study we demonstrate N+I resulted in objective responses in patients with genitourinary malignancy with neuroendocrine differentiation. ORR of 50% in small cell carcinoma is bladder cancer is noteworthy and will be evaluated further in ongoing expansion cohort of bladder or upper tract carcinoma with variant histology. Clinical trial information: NCT03333616. [Table: see text]

Mixed methods assessment of providers’ needs in the management of advanced renal cell carcinoma

313

Background: There is a paucity of data regarding the challenges associated with the timely and accurate diagnosis of Renal Cell Carcinoma (RCC) and its effective multidisciplinary management. This study aimed to assess the knowledge and skills of healthcare providers (HCPs) managing and coordinating the care of patients with advanced RCC (aRCC) across multidisciplinary teams. Methods: A sequential mixed methods needs assessment was conducted across the United States with medical oncologists (ONCs), nephrologists (NEPHs), physician assistants (PAs), nurse practitioners (NPs), and registered nurses (RNs). Interviews, transcribed and thematically analyzed, and online surveys, statistically analyzed, were triangulated. Results: A total of 305 HCPs completed an interview (n=40) or the survey (n=265): 78 ONCs, 62 NEPHs, 57 PAs, 55 NPs, 53 RNs. One third (33%) of HCPs reported suboptimal skills in adjusting the dose of a treatment for aRCC in the event of adverse reactions. Interviews underscored a lack of clarity for HCPs on when to reduce the dose or when to discontinue and/or switch to other drugs. Suboptimal knowledge and skills related to toxicities were found (Table). Breakdowns in communication across multidisciplinary teams were identified by 46% of HCPs. Of those, 61% occurred when monitoring side effects and 48% when referring to ONCs. Some NEPHs reported never, rarely, or sometimes being involved with ONCs in the management of nephritis (25%), chronic kidney disease (19%), or acute renal failure (24%). Interviews suggested the role of NEPHs in the care of aRCC is poorly recognized and that NEPHs are perceived to have limited time to spend in the care of cancer patients. Few NEPHs reported gaps in knowledge/skills managing key renal complications such as nephritis (13%/15%), chronic kidney disease (6%/15%), and acute renal failure (9%/9%). Conclusions: This study identified a need to improve HCPs’ knowledge of the signs/symptoms of treatment side effects, skills in identifying/referring patients to appropriate specialists, and skills in managing adverse events. Barriers to involving NEPHs in the co-management of aRCC included a lack of recognition of their role in managing treatment-induced renal complications.These results should inform educational interventions for professionals caring for aRCC patients.[Table: see text]

Treatment outcomes in patients (pts) with metastatic renal cell carcinoma (mRCC) with sarcomatoid and/or rhabdoid (S/R) features after progressive disease (PD) on immune checkpoint therapy (ICT): The MD Anderson Cancer Center experience

351

Background: S/R mRCC is an aggressive disease that is associated with improved response to ICT. Studies performed prior to the approval of ICT demonstrated poor outcomes of S/R RCC with VEGF targeted therapies (TT). Here, we report outcomes of pts with S/R mRCC treated with VEGF TT after PD on ICT. Methods: We retrospectively reviewed the records of pts with mRCC with sarcomatoid (S), rhabdoid (R), or sarcomatoid plus rhabdoid (S+R) features who received VEGF TT after PD on ICT. Clinical endpoints of interest were time on VEGF TT and OS from treatment initiation. Directed acyclic graphs were used to identify confounders for adjustment in regression models. Hazard ratios (HR) and 95% confidence intervals (95% CI) were calculated using multivariable Cox regression. Multivariable models adjusted for epithelial histology, IMDC risk, prior VEGF TT, and inclusion of cabozantinib in the post-ICT VEGF TT regimen. Results: 57 pts with metastatic S/R RCC (52 with clear cell and 5 with non-clear cell histology) received a VEGF TT after PD on ICT. 46% of pts received a VEGF TT prior to ICT. After PD on ICT, 67% of pts had IMDC intermediate-risk disease; the most commonly used VEGF TT were cabozantinib (44%), either sunitinib, pazopanib, or axitinib (24%), and a VEGF TT in combination with an ICT (21%). Pts with R RCC had significantly longer time on VEGF TT compared with S RCC (adjusted HR = 0.45, 95% CI 0.21-0.94, p = 0.034), whereas the OS comparison was inconclusive (adjusted HR = 0.77, 95% CI 0.36-1.62, p = 0.486). IMDC risk classification following ICT progression was predictive of OS (adjusted HR = 2.22, 95% CI 1.07-4.61, p = 0.032), whereas, its association with time on VEGF TT was less conclusive (adjusted HR = 1.78, 95% CI 0.88-3.60, p = 0.107). Conclusions: Patients with S/R mRCC derive clinical benefit from VEGF TT after progression on ICT, and it is similar to the benefit previously described for patients without S/R features. Our findings suggest that the type of S/R features present and IMDC risk score inform the clinical benefit that VEGF TT will produce in this setting.[Table: see text]

Safety and differential clinical activity of nivolumab plus ipilimumab (nivo-ipi) in patients (pts) with non-clear cell renal cell carcinoma (nccRCC)

356

Background: Pembrolizumab monotherapy recently showed promising efficacy in nccRCC. The objective response rate (ORR) by histology was 28.8% for papillary, 9.5% for chromophobe, and 30.8% for unclassified RCC (McDermott, JCO 2021). However, combination immunotherapy data are limited in nccRCC. Methods: We retrospectively evaluated the efficacy and safety of nivo-ipi in pts with nccRCC treated at our institution. ORR and progression-free survival (PFS) were determined using RECIST. Overall survival (OS) was measured from therapy start to death or last follow up. Results: Between November 2017 and July 2020, 27 pts with nccRCC were treated with nivo-ipi at our institution; 25 pts (93%) received nivo-ipi as first-line therapy and 14 pts (52%) had prior nephrectomy. Histology subtypes included 13 (48%) papillary (4 with sarcomatoid features [SF]), 7 (26%) chromophobe (4 with SF), and 7 (26%) unclassified. Sites of metastases included lung in 52%, bone in 37%, and liver in 22% of pts. IMDC risk was favorable (8%), intermediate (48%) and poor (44%). ORR in all pts was 30%; 7 pts achieved a partial response (PR), and 1 patient achieved a complete response (CR). ORR by histology subtype was 54% for papillary, 14% for chromophobe, and 0% for unclassified (table). Clinical benefit (defined as PR, CR, or stable disease [SD] for > 6 months) was achieved in 62% for papillary, 57% for chromophobe, and 29% for unclassified. At a median follow-up time of 17.1 months, for all 27 pts, median PFS was 7.2 months, and median OS was 18.5 months. Median OS per each variant histology subtype was not reached in papillary, 25.7 months in chromophobe, and 7.4 months in unclassified. Median PFS per variant histology subtype was 11.8 months in papillary, 4.0 months in chromophobe, and 2.8 months in unclassified. Seven pts (26%) developed Grade ≥3 toxicity: pneumonitis (2), colitis (2), hepatitis (1), rash (1), and immune-mediated glomerulonephritis (1). Conclusions: In this small retrospective study, nivo-ipi was well-tolerated in pts with nccRCC and yielded high ORR and prolonged PFS in papillary RCC but disappointing efficacy results in chromophobe and unclassified RCC. Molecular studies are ongoing to understand the mechanisms of response and resistance to nivo-ipi in these tumor subtypes.[Table: see text]

Efficacy of enfortumab vedotin in advanced urothelial cancer: Analysis from the Urothelial Cancer Network to Investigate Therapeutic Experiences (UNITE) study

BACKGROUND

Enfortumab vedotin (EV) is a novel antibody-drug conjugate approved for advanced urothelial cancer (aUC) refractory to prior therapy. In the Urothelial Cancer Network to Investigate Therapeutic Experiences (UNITE) study, the authors looked at the experience with EV in patient subsets of interest for which activity had not been well defined in clinical trials.

METHODS

UNITE was a retrospective study of patients with aUC treated with recently approved agents. This initial analysis focused on patients treated with EV. Patient data were abstracted from chart reviews by investigators at each site. The observed response rate (ORR) was investigator-assessed for patients with at least 1 post-baseline scan or clear evidence of clinical progression. ORRs were compared across subsets of interest for patients treated with EV monotherapy.

RESULTS

The initial UNITE analysis included 304 patients from 16 institutions; 260 of these patients were treated with EV monotherapy and included in the analyses. In the monotherapy cohort, the ORR was 52%, and it was >40% in all reported subsets of interest, including patients with comorbidities previously excluded from clinical trials (baseline renal impairment, diabetes, and neuropathy) and patients with fibroblast growth factor receptor 3 (FGFR3) alterations. Progression-free survival and overall survival were 6.8 and 14.4 months, respectively. Patients with a pure urothelial histology had a higher ORR than patients with a variant histology component (58% vs 42%; P = .06).

CONCLUSIONS

In a large retrospective cohort, responses to EV monotherapy were consistent with data previously reported in clinical trials and were also observed in various patient subsets, including patients with variant histology, patients with FGFR3 alterations, and patients previously excluded from clinical trials with an estimated glomerular filtration rate < 30 mL/min and significant comorbidities.

LAY SUMMARY

Enfortumab vedotin, approved by the Food and Drug Administration in 2019, is an important new drug for the treatment of patients with advanced bladder cancer. This study looks at the effectiveness of enfortumab vedotin as it has been used at multiple centers since approval, and focuses on important patient populations previously excluded from clinical trials. These populations include patients with decreased kidney function, diabetes, and important mutations. Enfortumab vedotin is effective for treating these patients. Previously reported clinical trial data have been replicated in this real-world setting, and support the use of this drug in broader patient populations.

First-Line Immuno-Oncology Combinations for Metastatic Clear Cell Renal Cell Carcinoma (mRCC): A Systematic Review of Phase III Clinical Trials

BACKGROUND: The introduction of immune checkpoint inhibitors rapidly changed treatment for patients with metastatic clear cell renal cell carcinoma (mRCC). First-line treatment now includes multiple immuno-oncology (IO) combinations that were approved over a short time period and were not directly compared in randomized clinical trials. Thus, clinicians face a challenge in individualizing first-line treatment to optimize clinical outcomes. OBJECTIVE: We sought to systematically review clinical outcomes for first-line IO combinations for patients with mRCC. METHODS: Literature reporting outcomes from phase III clinical trials that evaluated first-line IO combination therapies was identified through a search of the PubMed electronic database following PRISMA guidelines. Abstracts were screened to identify manuscripts that fit the search criteria, and then, a descriptive review was performed. RESULTS: Our literature search identified 2,229 abstracts that met the initial search criteria, and then, it was narrowed to 431 abstracts using filters for “clinical trial” and a “ten year” time window. After review of the abstracts, six manuscripts were selected for data extraction and subsequent review. CONCLUSION: When compared to sunitinib, four IO combinations improved overall survival as first-line treatment, and five improved progression free survival for patients with mRCC. These IO combination therapies have unique characteristics, so clinicians should take into account patient and cancer factors to individualize treatment recommendations.

Clinicopathological analysis and outcomes of inflammatory myofibroblastic tumours of the urinary bladder

OBJECTIVES

To describe clinical, imaging, and histopathological characteristics of inflammatory myofibroblastic tumour (IMT) of the urinary bladder and provide initial management and surveillance recommendations.

PATIENTS AND METHODS

We identified patients with IMT of the bladder treated at our facility from 1998 to 2020. Categorical variables were analysed with chi-square and Fisher's exact tests and continuous variables with the Mann-Whitney U-test. Kaplan-Meier analysis was performed for recurrence-free survival.

RESULTS

IMT was diagnosed in 35 patients with median (interquartile range [IQR]) follow-up of 20 (11.5-68.5) months. At initial diagnosis 86% were clinically organ-confined, 9% locally advanced, and 5% metastatic. Majority of patients (92%) had residual disease on re-staging transurethral resection (TUR). Of the 15 patients with organ-confined disease managed initially with TUR alone, five (33%) recurred at a median (IQR) of 5 (3.0-5.5) months from initial diagnosis. Presentation with visible haematuria was associated with recurrence (100% in recurrence vs 40% in non-recurrence groups, P = 0.044). There were no patients who developed a recurrence beyond 6 months after diagnosis. Partial or radical cystectomy was required in 23% and 9% of patients, respectively. One patient presented with metastatic disease associated with anaplastic lymphoma kinase (ALK) translocation and achieved a durable complete remission with 7 months of crizotinib therapy.

CONCLUSIONS

No patient with IMT treated with aggressive endoscopic management developed recurrences beyond 6 months. There were additionally no recurrences noted after definitive radical or partial cystectomy. These data support organ sparing therapy with aggressive endoscopic management and short-term surveillance in patients with localised IMT, with extirpative surgery reserved for refractory cases.

Pilot study of Tremelimumab with and without cryoablation in patients with metastatic renal cell carcinoma

Cryoablation in combination with immune checkpoint therapy was previously reported to improve anti-tumor immune responses in pre-clinical studies. Here we report a pilot study of anti-CTLA-4 (tremelimumab) with (n = 15) or without (n = 14) cryoablation in patients with metastatic renal cell carcinoma (NCT02626130), 18 patients with clear cell and 11 patients with non-clear cell histologies. The primary endpoint is safety, secondary endpoints include objective response rate, progression-free survival, and immune monitoring studies. Safety data indicate ≥ grade 3 treatment-related adverse events in 16 of 29 patients (55%) including 6 diarrhea/colitis, 3 hepatitis, 1 pneumonitis, and 1 glomerulonephritis. Toxicity leading to treatment discontinuation occurs in 5 patients in each arm. 3 patients with clear cell histology experience durable responses. One patient in the tremelimumab arm experiences an objective response, the median progression-free survival for all patients is 3.3 months (95% CI: 2.0, 5.3 months). Exploratory immune monitoring analysis of baseline and post-treatment tumor tissue samples shows that treatment increases immune cell infiltration and tertiary lymphoid structures in clear cell but not in non-clear cell. In clear cell, cryoablation plus tremelimumab leads to a significant increase in immune cell infiltration. These data highlight that treatment with tremelimumab plus cryotherapy is feasible and modulates the immune microenvironment in patients with metastatic clear cell histology.

Multimodal kidney‐preserving approach in localised and locally advanced high‐risk upper tract urothelial carcinoma

Objectives

Multimodal kidney‐preserving (MKP) strategies may be an option for patients with localised or locally advanced high‐risk upper tract urothelial carcinoma (UTUC) who have a relative contraindication for nephroureterectomy (NU).

Materials and methods

We studied patients with UTUC who were managed with MKP strategies, consisting of systemic anticancer therapy, with or without local/topical strategies after endoscopic control of intraluminal tumours. Primary end points were overall survival (OS) and progression‐free survival (PFS).

Results

Fourteen patients received MKP treatment between August 2013 and April 2020. Median baseline estimated glomerular filtration rate was 43 mL/min/1.73m². MKP was mainly pursued to avoid dialysis (10/14, 71%), followed by low performance status and/or comorbidities (2/14, 14%). All patients had received systemic therapy: chemotherapy (64%) and immunotherapy (36%). Endoscopic control and/or laser ablation was feasible in 7 (50%) patients. Calculated overall risk of non‐organ confined disease was 35%. Predicted 2‐year and 5‐year relapse‐free probability (RFP) was 74% (24–92%) and 62% (10–85%), respectively. Median follow‐up was 31 months (95% CI: 22.6, NE), median OS was 48.1 months (95% CI: 48.1, NE) and 2‐year OS probability was 0.89 (95% CI: 0.71, 1). Median metastases‐free survival was 48.1 months (95% CI: 26.8, NE), median PFS was 22.4 months (95% CI: 15.6, NE) and 2‐year PFS probability was 0.48 (0.26, 0.89).

Conclusion

Management of high‐risk localised or locally advanced UTUC with MKP strategies was associated with good tolerance, preservation of renal function, and comparable PFS and OS to predicted in vulnerable patients. Prospective studies with more patients are needed to evaluate these possible benefits relative to current standards.

Tumor diameter response in patients with metastatic clear cell renal cell carcinoma is associated with overall survival

OBJECTIVE

Tumor shrinkage of at least 10% after presurgical targeted molecular therapy (TMT) in renal cell carcinoma (RCC) patients has been associated with better overall survival (OS) outcomes. We characterized primary and metastatic tumor diameter response and OS in patients with metastatic clear cell RCC (ccRCC) who received preoperative TMT, immunotherapy, or both followed by deferred cytoreductive nephrectomy (dCN).

MATERIALS AND METHODS

Patients with metastatic ccRCC (n = 198) who underwent preoperative therapy and dCN from 2005 to 2019 were identified retrospectively. Longest primary and metastatic tumor diameters were calculated using cross-sectional images obtained before systemic therapy and dCN using the Response Evaluation Criteria in Solid Tumors. Patients were stratified by tumor shrinkage of at least 10% in the primary and/or metastatic tumors after systemic therapy. The Kaplan-Meier method was used to estimate OS, and Cox proportional hazards models were used to assess the association of patient characteristics with OS.

RESULTS

In total, 31.31% of patients had only metastatic tumor shrinkage (MTS) ≥ 10%, 8.08% had only primary tumor shrinkage (PTS) ≥ 10%, 32.32% had PTS and MTS ≥ 10%, and 28.28% had PTS/MTS < 10%. The median OS, number of patients with tumor shrinkage ≥ 10%, and International Metastatic Database Consortium (IMDC) scores were similar among the 3 systemic therapy groups (all P ≥ 0.80). Patients with MTS ≥ 10%, PTS ≥ 10%, and PTS/MTS ≥ 10% had significantly longer median OS compared to patients with PTS/MTS < 10% (P < 0.01). Patients with intermediate-risk IMDC scores had significantly longer median OS compared to patients in the poor-risk group. After adjusting for preoperative therapy and IMDC risk group, MTS ≥ 10%, PTS ≥ 10%, and PTS/MTS ≥ 10% were associated with better OS outcomes (HR 0.48 95% CI 0.32-0.73, P < 0.001; HR 0.48, 95% CI 0.23-0.98, P = 0.04; HR 0.44, 95% CI 0.29-0.67, P < 0.001, respectively).

CONCLUSIONS

Intermediate risk score and shrinkage of at least 10% in the primary tumor, metastases, or both were associated with better OS outcomes in patients with metastatic ccRCC who underwent dCN independent of the type of preoperative systemic therapy.

Evaluation of Technology-Enabled Monitoring of Patient-Reported Outcomes to Detect and Treat Toxic Effects Linked to Immune Checkpoint Inhibitors

IMPORTANCE

Immune checkpoint inhibitors can produce distinct toxic effects that require prompt recognition and timely management.

OBJECTIVE

To develop a technology-enabled, dynamically adaptive protocol that can provide the accurate information needed to inform specific remedies for immune toxic effects in patients treated with immune checkpoint inhibitors.

DESIGN, SETTING, AND PARTICIPANTS

An open-label cohort study was conducted at a single tertiary referral center from September 6, 2019, to September 3, 2020. The median follow-up duration was 63 (interquartile range, 35.5-122) days. Fifty patients with genitourinary cancers treated with immune checkpoint inhibitors were enrolled.

INTERVENTIONS

A fit-for-purpose electronic platform was developed to enable active patient and care team participation. A smartphone application downloaded onto patients' personal mobile devices prompted them to report their symptoms at least 3 times per week. The set of symptoms and associated queries were paired with alert thresholds for symptoms requiring clinical action.

MAIN OUTCOMES AND MEASURES

The primary end point of this interim analysis was feasibility, as measured by patient and care team adherence, and lack of increase in care team staffing. Operating characteristics were estimated for each symptom alert and used to dynamically adapt the alert thresholds to ensure sensitivity while reducing unnecessary alerts.

RESULTS

Of the 50 patients enrolled, 47 had at least 1 follow-up visit and were included in the analysis. Median age was 65 years (range, 37-86), 39 patients (83%) were men, and 39 patients (83%) had metastatic cancer, with the most common being urothelial cell carcinoma and renal cell carcinoma (22 [47%] patients each). After initial onboarding, no further care team training or additional care team staffing was required. Patients had a median study adherence rate of 74% (interquartile range, 60%-86%) and 73% of automated alerts were reviewed within 3 days by the clinic team. Symptoms with the highest positive predictive value for adverse events requiring acute intervention included dizziness (21%), nausea/vomiting (26%), and shortness of breath (14%). The symptoms most likely to result in unnecessary alerts were arthralgia and myalgia, fatigue, and cough.

CONCLUSIONS AND RELEVANCE

The findings of this cohort study suggest an acceptable and fiscally sound method can be developed to create a dynamic learning system to detect and manage immune-related toxic effects.

Durable responses in patients with genitourinary cancers following immune checkpoint therapy rechallenge after moderate-to-severe immune-related adverse events

Background

Immune checkpoint therapy (ICT) prolongs survival in subsets of patients with cancer but can also trigger immune-related adverse events (irAEs) requiring treatment discontinuation. Recent studies have investigated safety of ICT rechallenge after irAEs, and evidence suggests that rechallenge may be associated with improved antitumor responses. However, data are limited on response duration after ICT rechallenge, particularly after severe irAEs.

Objective

To evaluate safety and efficacy of ICT rechallenge after moderate-to-severe irAEs in patients with renal cell carcinoma (RCC), urothelial carcinoma (UC), and prostate cancer.

Methods

In this retrospective cohort study, medical records from September 25, 2013, to June 1, 2020, for patients with genitourinary (GU) cancers at MD Anderson Cancer Center who were rechallenged with the same or different ICT following irAEs were reviewed. Demographics, ICT exposure, irAEs (grade and treatment), ICT discontinuation or rechallenge, rates of subsequent irAEs (new or recurrent) and antitumor activity (objective response rates and response duration) were reviewed.

Results

Sixty-one patients with RCC, UC, and prostate cancer were rechallenged with ICT after experiencing 105 total irAEs. Objective response rates after rechallenge, that is, upgrade in response, were 14% in RCC (4/28), 21% in UC (3/14), and 0% in prostate cancer. All seven patients who achieved upgrade in response had initial grade 2 or 3 irAEs. Responses were durable among these seven patients, with median radiographic progression-free survival not reached (range: 3.7–66.4 months) as of the March 8, 2021, data cut-off (median follow-up 40.9 months (95% CI 35.3 to 46.5)). All achieved complete response except one patient who was lost to follow-up. The rate of subsequent grade 3 or 4 irAEs after rechallenge was 30%, with no fatal irAEs. The rate of recrudescence of the same irAE was 26% (16/61). 54% of patients received corticosteroids (33/61), and 21% received targeted immunosuppression (13/61) for the initial irAEs.

Conclusions and relevance

ICT rechallenge after moderate-to-severe irAEs was associated with deep and durable responses in a subset of patients with RCC and UC, with acceptable safety and no fatal events. Strategies to enable ICT resumption after moderate-to-severe irAEs, such targeted immunosuppression, warrant further study.

Validation of Prognostic Scores in Patients With Metastatic Urothelial Cancer Enrolling in Phase I Targeted Therapy or Next Generation Immunotherapy Trials

INTRODUCTION

Enrolling patients with metastatic urothelial carcinoma (mUC) in phase I trials provides an opportunity to identify biological drug activity. Developing prognostic scores may aid in patient selection for phase 1 trials.

PATIENTS AND METHODS

We analyzed records of patients with mUC who participated in targeted therapy and immunotherapy phase I clinical trials at MD Anderson Cancer Center (MDACC). The Bellmunt and Bajorin scores were calculated as bladder cancer-specific prognostic scores. The Royal Marsden Hospital (RMH) and MDACC scores were calculated as phase I prognostic scores. Hazard ratios (HR) were calculated using the Cox proportional hazard model. The prognostic value of the Bellmunt, Bajorin, RMH, and MDACC scores were assessed using the Likelihood ratio (LR) χ2 test and the c-index.

RESULTS

Between 2015 and 2019, 43 patients were enrolled in phase I trials and 12 were enrolled in >I trial leading to a total of 57 trial participants (TPs). Ninty-seven percent of TPs received prior platinum therapy and 60% received a prior checkpoint inhibitor. Median overall survival (OS) and progression-free survival (PFS) were significantly shorter with increasing Bajorin, RMH, or MDACC scores, but not with increasing Bellmunt score. The RMH (c-index=0.658, LR χ2=11.8, P=.008) and MDACC scores (c-index =0.66, LR χ2=12.76, P=.01) outperformed the Bajorin score (c-index=0.522, LR χ2=1.22, P=.5) and the Bellmunt score (c-index=0.537, LR χ2=0.36, P=.9) in predicting overall survivalover. The Bajorin, RMH, and MDACC scores, but not the Bellmunt score, were also predictive of progression-free survival (PFS)prog. The RMH and MDACC scores again outperformed the Bajorin scoreand the Bellmunt score for predicting PFS.

CONCLUSION

The RMH and MDACC phase I prognostic scores accurately predicted survival in patients with mUC and outperformed the bladder cancer-specific scores at time of enrollment on phase 1 clinical trials. The RMH and MDACC scores could optimize selection of patients with mUC for phase I clinical trials.

Definitive radiotherapy for extracranial oligoprogressive metastatic renal cell carcinoma as a strategy to defer systemic therapy escalation

OBJECTIVE

To study whether delivering definitive radiotherapy (RT) to sites of oligoprogression in metastatic renal cell carcinoma (mRCC) enabled deferral of systemic therapy (ST) changes without compromising disease control or survival.

PATIENTS AND METHODS

We identified patients with mRCC who received RT to three or fewer sites of extracranial progressive disease between 2014 and 2019 at a large tertiary cancer centre. Inclusion criteria were: (1) controlled disease for ≥3 months before oligoprogression, (2) all oligoprogression sites treated with a biologically effective dose of ≥100 Gy, and (3) availability of follow-up imaging. Time-to-event end-points were calculated from the start of RT.

RESULTS

A total of 72 patients were identified (median follow-up 22 months, 95% confidence interval [CI] 19-32 months), with oligoprogressive lesions in lung/mediastinum (n = 35), spine (n = 30), and non-spine bone (n = 5). The most common systemic therapies before oligoprogression were none (n = 33), tyrosine kinase inhibitor (n = 23), and immunotherapy (n = 13). At 1 year, the local control rate was 96% (95% CI 87-99%); progression-free survival (PFS), 52% (95% CI 40-63%); and overall survival, 91% (95% CI 82-96%). At oligoprogression, ST was escalated (n = 16), maintained (n = 49), or discontinued (n = 7), with corresponding median (95% CI) PFS intervals of 19.7 (8.2-27.2) months, 10.1 (6.9-13.2) months, and 9.8 (2.4-28.9) months, respectively. Of the 49 patients maintained on the same ST at oligoprogression, 21 did not subsequently have ST escalation.

CONCLUSION

Patients with oligoprogressive mRCC treated with RT had comparable PFS regardless of ST strategy, suggesting that RT may be a viable approach for delaying ST escalation. Randomised controlled trials comparing treatment of oligoprogression with RT vs ST alone are needed.

Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immunotherapy for the treatment of urothelial cancer

A number of immunotherapies have been developed and adopted for the treatment of urothelial cancer (encompassing cancers arising from the bladder, urethra, or renal pelvis). For these immunotherapies to positively impact patient outcomes, optimal selection of agents and treatment scheduling, especially in conjunction with existing treatment paradigms, is paramount. Immunotherapies also warrant specific and unique considerations regarding patient management, emphasizing both the prompt identification and treatment of potential toxicities. In order to address these issues, the Society for Immunotherapy of Cancer (SITC) convened a panel of experts in the field of immunotherapy for urothelial cancer. The expert panel developed this clinical practice guideline (CPG) to inform healthcare professionals on important aspects of immunotherapeutic treatment for urothelial cancer, including diagnostic testing, treatment planning, immune-related adverse events (irAEs), and patient quality of life (QOL) considerations. The evidence- and consensus-based recommendations in this CPG are intended to give guidance to cancer care providers treating patients with urothelial cancer.

Lenvatinib with or Without Everolimus in Patients with Metastatic Renal Cell Carcinoma After Immune Checkpoint Inhibitors and Vascular Endothelial Growth Factor Receptor-Tyrosine Kinase Inhibitor Therapies

INTRODUCTION

Lenvatinib (Len) plus everolimus (Eve) is an approved therapy for metastatic renal cell carcinoma (mRCC) after first-line vascular endothelial growth factor receptor-tyrosine kinase inhibitors (VEGFR-TKIs), but limited data exist on the efficacy of Len ± Eve after progression on immune checkpoint inhibitors (ICIs) and VEGFR-TKIs.

METHODS

We retrospectively reviewed the records of patients with mRCC at our institution who were treated with Len ± Eve after ICI and VEGFR-TKI. A blinded radiologist assessed objective response as defined by RECIST version 1.1. Descriptive statistics and the Kaplan-Meier method were used.

RESULTS

Fifty-five patients were included in the analysis. Of these patients, 81.8% had clear-cell histology (ccRCC), and 76.4% had International Metastatic RCC Database Consortium intermediate-risk disease. Median number of prior therapies was four (range, 2-10); all patients had prior ICIs and VEGFR-TKIs, and 80% were previously treated with ICI and at least two VEGFR-TKIs, including cabozantinib. One patient (1.8%) achieved a complete response, and 11 patients (20.0%) achieved a partial response, for an overall response rate (ORR) of 21.8%; 35 patients (63.6%) achieved stable disease. In all patients, median progression-free survival (PFS) was 6.2 months (95% confidence interval [CI], 4.8-9.4) and median overall survival (OS) was 12.1 months (95% CI, 8.8-16.0). In patients with ccRCC, ORR was 24.4%, PFS was 7.1 months (95% CI, 5.0-10.5), and OS was 11.7 months (95% CI, 7.9-16.1). 50.9% of patients required dose reductions and 7.3% discontinued treatment because of toxicity.

CONCLUSION

Len ± Eve demonstrated meaningful clinical activity and tolerability in heavily pretreated patients with mRCC after disease progression with prior ICIs and VEGFR-TKIs.

IMPLICATIONS FOR PRACTICE

As the therapeutic landscape for patients with metastatic renal cell carcinoma continues to evolve, this single-center, retrospective review highlights the real-world efficacy of lenvatinib with or without everolimus in heavily pretreated patients. This article supports the use of lenvatinib with or without everolimus as a viable salvage strategy for patients whose disease progresses after treatment with immune checkpoint inhibitors and vascular endothelial growth factor receptor-tyrosine kinase inhibitor therapies, including cabozantinib.

Survival outcomes in patients receiving immune checkpoint inhibitor (ICI) for metastatic small cell urothelial cancer (SCUC)

4543

Background: The prognosis in patients with metastatic SCUC (mSCUC) remains poor with median survival around 1 year with systemic chemotherapy. We aimed to investigate the impact of ICI on survival of patients with mSCUC. Methods: Patients who received systemic therapy at MD Anderson Cancer Center (MDACC) for de novo or metachronous mSCUC after completing local management. within 12 months of neoadjuvant or adjuvant chemotherapy were included in this cohort, with overall survival (OS) calculated from the time of receipt of initial chemotherapy. Hazard ratios (HR) and 95% confidence intervals (95% CI) were calculated using logrank test. Results: 102 patients with mSCUC received systemic therapy at MDACC between April 2006 and June 2020. Median age was 66 (range 24 – 86 years), male to female ratio was 5. Bladder was the primary site in 85 (83%), 45 (44%) had prior cystectomy and 9 (9%) had prior nephroureterectomy. Histologies included 51 (50%) with predominant small cell (SC) features, 28 (27%) with focal SC features, 20 (20%) with pure SC, and 3 (3%) mixed with large cell component. Thirty-nine (38%) received ICI during their disease course: 29 (28%) following front-line chemotherapy (15 of whom within 12 months of neoadjuvant/adjuvant platinum therapy), 5 (5%) combined with front-line chemotherapy, and 5 (5%) received ICI front-line (two of whom were able to receive second-line chemotherapy). ICI agents used included anti-PD-1 (n=19), anti-PD-L1 (n=12), anti-PD-1/anti-CTLA-4 (n=5), anti-PD-1/anti-TIM3 (n=1), anti-PD-1/anti-STAT3 (n=1), anti-PD-L1/PARPi (n=1). Those who received ICI at any time had an improved median OS compared to those treated with chemotherapy alone (20.1 vs 12 months), [HR=0.45, 95% CI 0.27-0.72, p=0.003]. When we limited the analysis to those with de novo mSCUC (n=36), those who received ICI at any time (n=13) had an improved median OS compared to those treated with chemotherapy alone (n=23) (not reached vs 9.41 months), [HR=0.28, 95% CI 0.12-0.68, p=0.03]. Among patients who received ICI (n=39), median OS in those with liver metastases (n=11) was numerically shorter than those without (n=28) (13.1 vs 21.6 months), [HR=1.83, 0.59-5.7, p=0.21]. Conclusions: ICI improves OS for patients with mSCUC. Although clinical trials remain difficult in these rare variants, further prospective studies are indicated to confirm this finding.

Very late recurrence in germ cell tumor of the testis: Lessons and implications

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Background: Up to 30% of patients with germ cell tumor of the testis (TGCT) develop recurrent disease after initial treatment. The majority of recurrences occur in the first 2 years after treatment. Very late recurrence (LR), i.e. > 5 years after initial presentation, occurs in about 1% of patients with TGCT and is associated with poor prognosis. Current guideline does not require follow-up after 5 years to detect LR, except in those presenting with metastatic NSGCT. Methods: We retrospectively reviewed the records of patients from the Genitourinary Medical Oncology clinic at the M. D. Anderson Cancer Center, who developed recurrent disease > 5 years after their initial diagnosis of TGCT. Specifically, we examined the pathology and location of their primary and recurrent tumors, treatments rendered (e.g., surgery, radiotherapy, chemotherapy), and overall survival after LR. Overall survival from the time of LR was estimated using Kaplan-Meier estimates and compared for patient subgroups with log rank tests. Fisher’s exact test was used to compare proportions in patient subgroups. Results: We identified 25 patients who developed LR between July 2007 and August 2020. Age at time of LR: median 46 years (range, 29-61); time of late LR: median 16.1 years (range, 6.8-33.1 years) after diagnosis. Stage at time of diagnosis: I – 5, II-IIIA – 13, IIIB-C – 7. Pathology of primary: nonseminoma with yolk sac tumor or teratoma – 15, nonseminoma without yolk sac tumor or teratoma – 1, not available – 9. Pathology of LR: somatic transformation to carcinoma – 9, somatic transformation to sarcoma – 2, nonseminoma with yolk sac tumor or teratoma – 10, nonseminoma without yolk sac tumor or teratoma – 2, not available – 2. Overall, 5 patients (20%) had LR in retroperitoneum alone, 6 patients (24%) had non-retroperitoneal nodal or pulmonary metastases, and 14 patients (56%) had non-pulmonary visceral metastases. Nine patients (36%) are deceased, ten patients (40%) are alive without evidence of disease (NED), and 6 patients are alive with disease (24%). With a median follow-up of 42 months, 68% of patients are alive 3 years after LR. Patients with prior post-chemotherapy consolidation surgery have longer survival, 80% vs. 53% at 3 years, respectively (p = 0.01). Additionally, at their last follow-up 9/12 vs. 1/13 patients were NED with vs. without prior post-chemotherapy consolidation surgery, respectively (p = 0.001). Conclusions: Patients with LR > 5 years after initial presentation tend to harbor nonseminoma (with yolk sac tumor and or teratoma). Among these patients, a majority who did not undergo surgery to remove residual disease after chemotherapy developed somatic transformation and succumbed to their LR. Further investigation into rates of LR among all patients may be warranted given the poor survival after LR.