Targeted Therapy in Patients with Metastatic Male Germ Cell Tumors

Phase II Study of Sunitinib in Tumors With c-KIT Mutations: Results From the NCI MATCH ECOG-ACRIN Trial (EAY131) Subprotocol V

PURPOSE

The NCI-MATCH study is a tumor-agnostic platform trial enrolling patients to targeted therapies on the basis of genomic alterations. Subprotocol V investigated sunitinib in patients with tumors harboring c-KIT mutations.

METHODS

EAY131-V, is an open-label, single-arm, phase II study. Eligible patients had malignancies containing somatic c-KIT mutation on exons 9, 11, 13, or 14. Exclusions were mutations on exons 17 and 18, gastrointestinal stromal tumors, renal cell carcinoma, and pancreatic neuroendocrine tumors. Patients received sunitinib 50 mg orally once daily for 4 weeks with 2-week rest per cycle, until disease progression or unacceptable toxicity. Primary end point was objective response rate (ORR); secondary end points were progression-free survival (PFS) at 6 months, PFS, overall survival, and toxicities.

RESULTS

Between November 1, 2016, and May 21, 2020, 10 patients were enrolled and nine were eligible and started treatment. The median age was 62 years (range, 30-76), 77.8% received two previous lines of systemic therapy, and 22.2% received >3 lines. The most common histology was melanoma (44%) and then squamous cell carcinoma of the lung or thymus (33%). There were two partial responses with an ORR of 22.2% (90% CI, 4.1 to 55) and stable disease in 44%. All patients demonstrated tumor shrinkage of target lesions. The estimated 6-month PFS was 33.3% (90% CI, 15.4 to 72.4). Grade 3-4 toxicities occurred in five patients (55.6%). This arm was closed in 2022 on the basis of low accrual. Prevalence of eligible c-KIT mutations after screening 5,540 patients was 0.45%.

CONCLUSION

Sunitinib for c-KIT mutations did not meet the primary end point, but in this small sample size, a potential signal cannot be ruled out. Rate of eligible c-KIT mutations was low, affecting accrual to this arm.

Management of recurrent and persistent malignant ovarian germ cell tumors: a narrative review

Approximately 10% of patients with malignant ovarian germ cell tumors will experience a tumor relapse. Given the rarity of malignant ovarian germ cell tumors, management of these patients is challenging. Secondary cytoreductive surgery can be considered for carefully selected patients with a goal to achieve complete gross or optimal resection. For patients with platinum sensitive disease who have already received platinum-based chemotherapy, standard dose chemotherapy with paclitaxel/ifosfamide/cisplatin or vinblastine/ifosfamide/cisplatin can be considered. High-dose chemotherapy protocols at specialized centers should be explored even for patients with platinum-resistant disease; however, optimal timing is under investigation. A subset of patients with malignant ovarian germ cell tumors harbors potentially actionable genomic alterations. Further research is required to identify novel therapeutic approaches for these patients.

Alternative Treatment with Every-Other-Day Dosing of Sunitinib for Metastatic Renal Cell Carcinoma: Extended Follow-Up

INTRODUCTION

We investigated the efficacy and safety of every-other-day dosing of sunitinib for the treatment of metastatic renal cell carcinoma (mRCC) with extended follow-up and the impact of immune checkpoint inhibitor (ICI) drugs.

METHODS

Thirty-two patients received standard dosing treatment (standard group), and 32 received every-other-day treatment (experimental group). Efficacy endpoints included progression-free survival (PFS), overall survival (OS), and objective response rate. We also analyzed the clinical course of patients treated with nivolumab after sunitinib.

RESULTS

The minimum follow-up was 42 months. Median PFS and OS were significantly longer in the experimental group compared with the standard group (27.6 vs. 6.2 and 87.1 vs. 24.6 months, respectively). The incidence of dose interruption of sunitinib caused by adverse events was significantly lower in the experimental group than in the standard group (28.1% vs. 56.3%, p = 0.042). Multivariate analysis showed that every-other-day dosing was a significant independent prognostic factor (p = 0.038), although nivolumab use was not (p = 0.232). Twelve patients were treated with nivolumab after sunitinib, and patients who did not respond to nivolumab tended to respond to pretreatment sunitinib for a long period.

DISCUSSION/CONCLUSION

Long-term follow-up confirmed the efficacy and safety of every-other-day dosing of sunitinib for mRCC patients in the ICI era.

Salvage management of patients with relapsing testicular germ cell tumors

PURPOSE OF REVIEW

This review aims to summarize the latest evidence of medical and surgical treatment options for patients with relapsing testicular germ cell tumors.

RECENT FINDINGS

Depending on International Germ Cell Cancer Classification Group risk classification 10-50% of patients with metastatic TGCT develop relapse which needs further multimodality treatment. With regard to therapy, early relapses are stratified according to their prognostic risk profile which results in a 3-year overall survival between 6% in the very high to 77% in the very low risk group. Prognostic risk score dictates systemic therapy which might be second line chemotherapy (TIP, PEI) or high dose chemotherapy. Any residual masses following salvage chemotherapy need to be completely resected due the presence of viable cancer and/or teratoma in more than 50% of cases. Targeted therapy in men with druggable mutations is for individualized cases only. Patients with late relapses developing more than 2 years after first-line chemotherapy are best managed by surgery. Desperation surgery is reserved for those patients with rising markers during or immediately after chemotherapy and good risk factors such as rising alpha-fetoprotein, <3 metastatic sites and complete resectability. Multimodality treatment will result in long-term cure of 25% to 60%. Due to the complexity of treatment, chemotherapy as well as surgery should be performed in highly experienced centres only.

SUMMARY

Multimodality treatment to salvage relapsing patients with metastatic testis cancer requires extensive experience for both systemic therapy and surgery. If done properly, it will result in moderate to high cure rates. Personalized therapeutic options are currently evaluated in clinical trials.