The second day of ESMO included the oral genitourinary (GU) oncology session that focused on renal cell (kidney) and urothelial (bladder) carcinoma.
Several years ago, the SWITCH study evaluated the sequence of sunitinib and sorafenib showing similar overall progression free survival and overall survival regardless of the order by which each drug was utilized. At ESMO 2017, results of the SWITCH-II trial were presented. This study tested the sequence of pazopanib and sorafenib in patients with advanced RCC of any histology (i.e. clear cell or non-clear cell). The study sought to enroll 544 patients, but stopped after 377 patients due to slow accrual. Only half of the patients remained on study and switched to their assigned drug after tumor growth on drug #1. Overall, while the study didn’t complete planned accrual, there was a trend for improved progression-free and overall survival for the pazopanib → sorafenib sequence.
Historically when most patients were treated with cytokines (IL-2 and interferon), two randomized trials by U.S. and European cooperative groups showed that in the setting of metastatic kidney disease, patients live longer by first removing the kidney mass and then treating with interferon rather than treating with interferon without removal of the kidney. Since the introduction of new therapies in late 2005 which have higher rates of tumor shrinkage and longer lifespans for patients, it is unknown if patients should still have their kidney tumor removed prior to drug therapy.
In the EORTC 30073 SURTIME trial, European investigators decided to try to assess whether tumors remained under control longer and patients lived longer if surgery was performed first or if patients initiated sunitinib for 3 cycles prior to cytoreductive nephrectomy. Because enrollment was slow, the study design was changed to assess the percent of patients that were free of tumor progression at 28 weeks. Ninety-nine patients were randomized to immediate versus delayed surgery, most with large kidney tumors and intermediate-risk cancer. Overall there was no difference in the percent with cancer progression at 28 weeks with either approach. With the caveat of a small study, there were trends for longer survival and less surgical complications in those with delayed surgery. While the amended study is not able to prove that delayed surgery is the better approach, it gives comfort for those physicians/patients that the choice to initiate medical therapy and then re-evaluate for surgery is acceptable. We await the results of the larger CARMENA study that is testing surgery followed by drug versus drug alone (with no surgery) to see if removal of the primary kidney tumor is necessary.
Additionally, two early-phase studies of novel drug combinations of immunotherapy + targeted therapy were presented. In a phase I study led by the NCI, the safety of the combinations of cabozantinib/nivolumab and cabozantinib/nivolumab/ipilimumab were tested in patients with a number of different treatment-refractory tumor types, especially urothelial and other types of bladder cancers. Overall, both combinations were deemed to be safe and are moving forward in a phase III trial. However, many toxicities did occur and most patients needed to reduce the dose of at least one drug so these combinations should only be used in a clinical trial setting.
The phase II portion of a phase I/II study testing the combination of lenvatinib + pembrolizumab. The initial (phase 1) portion of the study presented at ESMO 2016 determined the safe dose in patients with different types of tumors (mostly RCC). This year, new results were presented with 22 additional patients added to the 8 previously treated on the phase I portion. Overall, there was an impressive tumor response rate of 63%, with 83% significant tumor shrinkage in those patients treated in the 1st line setting. This combination is also being tested in a phase III study for patients with advanced RCC which will soon be opening at Weill Cornell Medicine and NewYork-Presbyterian.
We’ve outlined some key highlights from the first day of the conference below.
For men with newly diagnosed “hormone sensitive” high risk / advanced prostate cancer, several recent studies have changed the standard of care. Data from the CHAARTED, STAMPEDE, and LATITUDE studies that investigated the addition of docetaxel or abiraterone and low dose prednisone to standard androgen deprivation therapy (ADT) for men with advanced prostate cancer has led to significantly longer and better lives. Updates to this data were presented at ESMO 2017.
The STAMPEDE study included an overlapping period where some men were randomized to ADT + docetaxel chemotherapy and others were randomized to ADT + abiraterone/prednisone. It was comforting to know that whether men received either chemotherapy with docetaxel for 6 cycles or abiraterone and prednisone continuously for at least 2 years that they lived significantly longer compared to men receiving the old standard of ADT alone.
The interesting comparison presented at ESMO 2017 was that men who took abiraterone had longer time to cancer progression (mostly assessed by rising PSA). There were similar overall survival outcomes with either initial treatment strategy. As expected, the types of side effects were different depending upon the type of treatment, but severe toxicity was equally common with either type of treatment.
For the first time, “patient reported outcomes” assessing symptoms and quality of life on the LATITUDE study (including men with high-risk metastatic disease treated with ADT + abiraterone/prednisone or ADT + placebos) were presented. In addition to living significantly longer and having major delays in cancer growth, men taking ADT + abiraterone/prednisone had better pain control and were less likely to have reductions in quality of life, particularly after the initial 4 months on treatment.
Prostate-specific membrane antigen (PSMA) is a protein that is on the cell surface of most prostate cancers and can be used as a treatment target since it is not present many other places in the body. At Weill Cornell Medicine and NewYork-Presbyterian, we have been targeting this protein with radioactive particles for more than a decade. Other institutions have also more recently begun using this approach. Over the past several years, there have been many patients receiving this type of therapy in Europe who may have benefitted from this treatment, but no real prospective clinical trials have been performed. Australian researchers presented data at ESMO in which they enrolled and treated 30 men whose tumors “lit up” on PSMA-PET scans with 177Lu-PSMA-617 in a clinical trial. Patients received up to 4 cycles of therapy. Most patients experienced a significant decrease in PSA, some had tumors shrink on scans, and severe side effects were limited.
We have previously published on the (initially) surprisingly high frequency of inherited “germline” alterations in men with advanced prostate cancer. A Spanish group performed a prospective study of 419 men and found that about 9% had alterations in genes that affect the body’s ability to repair damaged DNA. Among the 6.2% with the most common alterations – BRCA2, ATM, and BRCA1 — overall survival was not significantly shorter compared to men without these genetic mutations. However, when examining just the most common BRCA2 gene, men did not live as long. Whether or not these inherited DNA alterations were present, men could respond to approved therapeutic agents, so if clinical trials are not available men should be encouraged to take standard hormonal or chemotherapy.
Each year, the American Society of Clinical Oncology (ASCO) Annual Meeting brings together more than 30,000 oncology professionals. At this year’s meeting in Chicago, physicians and scientists presented the latest research findings in an effort to bring the best cancer treatments to patients across the United States and the world. We’ve outlined some of the genitourinary (GU) oncology highlights, broken down by disease type.
At this year’s meeting, there was also some important research presented related to communication, quality of life and survival. In a study that involved patients with GU cancers, as well as those with other types of tumors, patients were randomized to two groups: 1) a control group of standard care 2) a group to utilize a web-based patient-reported outcome questionnaire between visits. Results from any answers completed in the online system were sent to the treatment team in real time. In this study, the patients that were randomized to the online questionnaire group experienced better quality of life. In addition, these patients lived longer, with a 17% improvement in survival simply by using the online tracker reporting symptoms to their treatment team between visits. While the study was only conducted at a single institution, it underscores the importance of communicating and relaying any symptoms to your treatment team members responsible for your medical care (generally physicians, nurses and advanced practitioners).
The results from two large phase 3 clinical trials will lead to a change in the standard of care treatment for men with advanced prostate cancer. The LATITUDE and STAMPEDE trials investigated the addition of abiraterone and low dose prednisone to standard androgen deprivation therapy (ADT) for men with advanced prostate cancer. Similar to the unprecedented results presented at ASCO in 2014 (CHAARTED) and 2015 (STAMPEDE) with the use of docetaxel chemotherapy, a major improvement in overall survival was demonstrated, improving length of life by nearly 40%. The results from these studies will provide an additional treatment option for men presenting with advanced prostate cancer.
For men with metastatic castration-resistant prostate cancer (mCRPC), a randomized phase 2 trial demonstrated no significant differences in the efficacy, or effectiveness, of abiraterone or enzalutamide, two of the leading treatments for prostate cancer that is resistant to hormonal therapy. This research finding was consistent with most clinicians’ belief that either drug may be utilized, allowing physician and patient choice. Importantly, the study incorporated a number of interesting biomarkers using circulating tumor cell (CTC) DNA from a liquid biopsy, and the data gleaned from the DNA revealed prognostic insights about disease aggressiveness and biology. Another study showed a lack of utility to continue enzalutamide after disease progression, confirming the current practice of switching treatments after cancer growth.
Additional data was presented on genomic signatures from prostate tissue, which in combination with clinical data, are more powerful in indicating prognosis in men who receive treatment for clinically localized (low stage / early) prostate cancer.
Prostate cancer acquires resistance to systemic treatment as a result of tumor evolution and selection, but repeat biopsies to study how cancers evolve are challenging, invasive, and may be confounded by tumor heterogeneity. Dr. Himisha Beltran evaluated a non-invasive approach: whole exome sequencing of circulating tumor DNA in the blood. Additional data utilizing circulating tumor cell (CTC) counts as an early indicator of response may speed drug development. Clinical trials are currently evaluating measuring circulating tumor cell counts as a biomarker for whether or not treatments are working. This may be a better indicator than measuring levels of prostate specific antigen (PSA), the current indicator for response.
Dr. Scott Tagawa presented a trial-in-progress update about the clinical trial he is leading at Weill Cornell Medicine and NewYork-Presbyterian utilizing the small molecule lutetium 177Lu-PSMA-617 to target prostate-specific membrane antigen (PSMA). PSMA is a protein abundantly expressed in 85-90 percent of metastatic prostate cancer cells, and this is the first U.S. trial of its kind. Learn more about this radionuclide therapy-based clinical trial and the eligibility criteria.
Additionally, there were many research updates presented in the area of neuroendocrine prostate cancer (NEPC), an aggressive subtype of prostate cancer that is resistant to many traditional treatment types. Dr. Loredana Puca received a Merit Award from the Conquer Cancer Foundation for her research examining the potential use of antibody-drug conjugate rovalpituzumab tesirine for treatment of NEPC. View the abstract and learn more about our open clinical trial using this antibody-drug conjugate. Dr. Himisha Beltran highlighted the significance of the loss of tumor suppressor ZFP36 in prostate cancer patients.
Prostate cancer was the first tumor type to have a cancer vaccine (sipuleucel-T) lead to longer survival, but the drug’s activity may be limited on its own. In a randomized phase 2 trial, receiving sipuleucel-T in combination with indoximod – a drug with the potential to improve immune response – kept the cancer at bay more than twice as long compared to those who received sipuleucel-T plus a placebo. This was an exciting research update showing promise for patients with prostate cancer.
New research using tumor and liquid (blood-based) biopsies demonstrated that a majority of tumors and circulating tumor cells in men with metastatic castration-resistant prostate cancer express a protein called Trop-2, justifying a targeted treatment approach. With this knowledge, we are now evaluating the safety and efficacy of IMMU-132, an immunotherapy-based drug that targets Trop-2, in an open clinical trial for men with prostate cancer.
Bladder Cancer and Other Urothelial Cancers:
Dr. Bishoy Faltas was invited to present at the ASCO Clinical Science Symposium entitled “Expanding the Actionable Landscape: Bladder Cancer Genomics — Unlocking the Genome: Insights Into Risk and Response in Bladder Cancer.”
During this session, Dr. Faltas discussed the genomics of urothelial cancer, and highlighted the latest research describing new data on the frequency of inherited (germline) mutations as well as tumor (somatic) genomics and relationship to response to chemotherapy and immunotherapy. Patients with “upper tract” urothelial cancer (tumors arising in the kidney or ureter) in particular have a higher chance of harboring an inherited mutation. Different genomic alterations in the tumors may be separated into groups that are associated with better responses to chemotherapy and immunotherapy. This is becoming more clinically relevant as we can test for these genes and the number of treatment options is expanding.
Additionally, updated results of the KEYNOTE-045 study confirmed the overall survival benefit of the anti-PD1 immune checkpoint inhibitor pembrolizumab (Keytruda) compared to second-line chemotherapy in patients with prior platinum-based chemotherapy. Importantly, this was the first head-to-head trial to demonstrate the superiority of immunotherapy over chemotherapy in urothelial cancer.
Several different combination studies for the treatment of advanced renal cell carcinoma (RCC) were presented at the 2017 ASCO Annual Meeting. While some studies demonstrated promising response data, significant toxicity of some combinations underscored the importance of clinical trials and the recommendation to avoid combinations outside of the research setting, which is regulated and in which these types of side effects can be monitored. Several randomized phase III trials testing combination therapy are ongoing with results anticipated to lead to changes in standard of care.
Unfortunately, despite imaging that indicates no evidence of cancer metastases (spread), many patients are not cured with surgery alone. Treatment of many cancers incorporate the use of systemic (medical) therapy in addition to surgery to increase cure rates. For the most part, this strategy has not been overwhelmingly successful in the setting of renal cell carcinoma (RCC). Unfortunately, another “negative” phase III trial showed that the addition of pazopanib (Votrient) to surgery did not improve cure rates for patients with RCC. Additional data was presented utilizing either clinical or genomic biomarkers that may assist physicians in choosing patients that might benefit from the addition of the oral drugs following surgery. We continue to await the results of additional completed studies and some currently enrolling studies utilizing immunotherapy before/after surgery.