Highlights from the 2022 American Society of Clinical Oncology Genitourinary Cancers Symposium

Renee K. McAlister, PharmD, BCOP

RK-McAlister

Clinical Pharmacy Specialist, Genitourinary Oncology
Vanderbilt-Ingram Cancer Center
Nashville, TN

The 2022 American Society of Clinical Oncology Genitourinary (GU) Cancers Symposium took place February 17-19 in San Francisco, CA. Karen E. Knudsen, MBA, PhD, the Chief Executive Officer of the American Cancer Society, provided the keynote address on Friday and discussed inequalities of care in cancer patients. Dr. Knudsen discussed how lack of access to affordable housing/transportation, healthcare, insurance coverage, and other variables can lead to differences in outcomes and mortality, particularly in GU cancers.

Each day of the conference was dedicated to a different cancer diagnosis – prostate cancer (Thursday), bladder cancer (Friday), and kidney/testicular/penile/adrenal cancers (Saturday). Two topics of interest that were discussed in a variety of presentations across several tumor types were the use of biomarkers to drive treatment decision making and the approach to treating a patient with a rare histological variant.

There were also several abstracts presented which will lead to practice changes or confirm recent practice changes in treatment of patients with GU cancers. These abstracts are described below.

ARASENS: darolutamide + ADT + docetaxel for mHSPC
Dr. Matthew Smith of Massachusetts General Hospital Cancer Center in Boston, MA presented the first results of ARASENS, a randomized, phase III, double-blind trial comparing darolutamide + standard androgen-deprivation therapy (ADT) versus darolutamide + ADT + docetaxel for metastatic hormone-sensitive prostate cancer (mHSPC).1 Patients were randomized 1:1 to darolutamide 600 mg twice daily (n=651) or placebo (n=655) in addition to ADT + docetaxel. Randomization was stratified by extent of disease according to TNM (M1a vs M1b vs M1c) and alkaline phosphatase levels. For the primary endpoint of overall survival, darolutamide decreased the risk of death by 32.5% versus placebo (hazard ratio [HR] 0.675, 95% confidence interval [CI] 0.568-0.801; p<0.0001); this finding was consistent amongst all subgroups analyzed. Key secondary endpoints were also in favor of darolutamide, including time to castrate-resistance (HR 0.357, 95% CI 0.302-0.421; p<0.0001), time to pain progression (HR 0.792, 95% CI 0.660-0.950; p=0.0058). Adverse events were similar between treatment arms and were largely attributed to the docetaxel component of the treatment regimen.

The authors concluded that in patients with new mHSPC, initiation of darolutamide in combination with ADT + docetaxel improves overall survival and key secondary endpoints compared ADT + docetaxel alone. The companion paper was published in the New England Journal of Medicine with full results.2

EV-103 Cohort H: neoadjuvant enfortumab vedotin for cisplatin-ineligible MIBC
Dr. Daniel P. Petrylak of Yale Cancer Center in New Haven, CT discussed the results of Cohort H of EV-103, a phase Ib/II trial which studied the use of enfortumab vedotin in cisplatin-ineligible patients with muscle invasive bladder cancer (MIBC).3 This cohort enrolled patients with cT2-T4aN0M0 MIBC who were eligible for radical cystectomy and pelvic lymph node dissection (RC+PLND). Enrolled patients received 3 cycles of neoadjuvant enfortumab vedotin 1.25 mg/kg on days 1 and 8 of a 21-day cycle. Preliminary results from 22 patients were presented. Of the enrolled patients, 68.2% had predominant urothelial cancer (31.8% had a mixed histology), 19 patients completed all 3 cycles of neoadjuvant enfortumab vedotin, and 21 underwent RC+PLND. The primary endpoint, pathological complete response rate, was achieved in 36.4% of patients. A key secondary endpoint, pathologic downstaging, was seen in 50% of patients. No new safety signals were reported with the use of enfortumab vedotin in this setting.

The authors concluded that neoadjuvant enfortumab vedotin showed promising activity in cisplatin-ineligible patients with MIBC, an area of treatment with high unmet need, and note that there are ongoing phase II and III programs to confirm benefit.

Neoadjuvant chemotherapy for UTUC
Dr. Wesley Yip of Memorial Sloan Kettering Cancer Center in New York, NY presented the results of a phase II, multicenter trial studying neoadjuvant cisplatin + gemcitabine in patients with high-grade upper tract urothelial carcinoma (UTUC).4 Enrolled patients (n=57) received cisplatin + gemcitabine for 4 cycles followed by surgical resection and lymph node dissection. The primary endpoint, pathologic response rate (defined as less than pT2N0), was achieved in 63% of patients, including 11 patients (19%) with a complete response (defined as pT0N0). Secondary endpoints included progression free survival (2-year 76% and 5-year 61%) and overall survival (2-year 93% and 5-year 79%).

The authors concluded that neoadjuvant cisplatin + gemcitabine for high-risk UTUC improves pathological response, which translates to improvements in PFS and OS in patients who demonstrate a pathologic response, and should be the new standard of care for patients with high-risk UTUC.

KEYNOTE-564: 30-month follow-up results for adjuvant pembrolizumab for RCC
Dr. Toni Choueiri of Lank Center for Genitourinary Oncology at Dana-Farber Cancer Institute in Boston, MA presented a 30-month follow up of KEYNOTE-564 which was a double-blind, multicenter, randomized study comparing adjuvant pembrolizumab versus placebo for patients with renal cell carcinoma (RCC) at intermediate-high or high risk of recurrence after resection (defined as pT2, grade 4 or sarcomatoid, N0 M0; pT3 or pT4, any grade, N0 M0; any pT, any grade, N+ M0; or M1 with no evidence of disease). Patients were randomized 1:1 to pembrolizumab (n=496) or placebo (n=498).

At 30-month follow up, the primary endpoint of disease-free survival continued to be longer with pembrolizumab compared to placebo at 30 months (HR 0.63, 95% CI 0.50-0.80; p<0.0001); this benefit was seen amongst subgroups. Overall survival, a key secondary endpoint, was also numerically improved with pembrolizumab versus placebo (HR 0.52, 95% CI 0.31-0.86; p=0.0048), however this p-value was not statistically significant at time of analysis. There were no new safety signals reported with the use of pembrolizumab in this setting.

The authors concluded that the use of adjuvant pembrolizumab continued to provide meaningful improvement in DFS at 30 months of follow-up in patients with RCC following resection.

The 2023 ASCO GU Cancers Symposium will be held Feb 16-18 in San Francisco, CA. Additional information can be found at https://conferences.asco.org/gu/dates-know.

References:

  1. Smith MR, Hussain MHA, Saad F, et al. J Clin Oncol 40, 2022 (suppl 6; abstr 13). doi:10.1200/JCO.2022.40.6_suppl.013
  2. Smith MR, Hussain M, Saad F, et al. Darolutamide and survival in metastatic, hormone-sensitive prostate cancer. N Engl J Med. 2022 (Online ahead of print). doi:10.1056/nejmoa2119115.
  3. Petrylak DP, Flaig TW, Mar N, et al. J Clin Oncol 40, 2022 (suppl 6; abstr 435). doi:10.1200/JCO.2022.40.6_suppl.435.
  4. Yip W, Coleman J, Wong NC, et al. J Clin Oncol 40, 2022 (suppl 6; abstr 440). doi:10.1200/JCO.2022.40.6_suppl.440.
  5. Choueiri TK, Tomczak P, Park SH, et al. J Clin Oncol 40, 2022 (suppl 6; abstr 290). doi:10.1200/JCO.2022.40.6_suppl.290.