Aung Naing

Phase 1/2 trial of avelumab combined with utomilumab (4‐1BB agonist), PF‐04518600 (OX40 agonist), or radiotherapy in patients with advanced gynecologic malignancies

AbstractBackgroundImmune checkpoint blockade has shown mixed results in advanced/recurrent gynecologic malignancies. Efficacy may be improved through costimulation with OX40 and 4‐1BB agonists. The authors sought to evaluate the safety and efficacy of avelumab combined with utomilumab (a 4‐1BB agonist), PF‐04518600 (an OX40 agonist), and radiotherapy in patients with recurrent gynecologic malignancies.MethodsThe primary end point in this six‐arm, phase 1/2 trial was safety of the combination regimens. Secondary end points included the objective response rate (ORR) according to Response Evaluation Criteria in Solid Tumors and immune‐related Response Evaluation Criteria in Solid Tumors, the disease control rate (DCR), the duration of response, progression‐free survival, and overall survival.ResultsForty patients were included (35% with cervical cancer, 30% with endometrial cancer, and 35% with ovarian cancer). Most patients (n = 33; 83%) were enrolled in arms A–C (no radiation). Among 35 patients who were evaluable for efficacy, the ORR was 2.9%, and the DCR was 37.1%, with a median duration of stable disease of 5.4 months (interquartile range, 4.1–7.3 months). Patients with cervical cancer in arm A (avelumab and utomilumab; n = 9 evaluable patients) achieved an ORR of 11% and a DCR of 78%. The median progression‐free survival was 2.1 months (95% CI, 1.8–3.5 months), and overall survival was 9.4 months (95% CI, 5.6–11.9 months). No dose‐limiting toxicities or grade 3–5 immune‐related adverse events were observed.ConclusionsThe findings from this trial highlight that, in heavily pretreated patients with gynecologic cancer, even multidrug regimens targeting multiple immunologic pathways, although safe, did not produce significant responses. A DCR of 78% in patients with cervical cancer who received avelumab and utomilumab indicates that further research on this combination in select patients may be warranted.

The clinical efficacy and safety of single-agent pembrolizumab in patients with recurrent granulosa cell tumors of the ovary: a case series from a phase II basket trial

Background Treatment of recurrent, unresectable granulosa cell tumor (GCT) of the ovary can be challenging. Given the rarity of the tumor, alternative therapies have been difficult to evaluate in large prospective clinical trials. Currently, to our knowledge, there are no reports of the use of immune checkpoint inhibitors in GCT patients. Here, we present a case series of GCT patients treated with pembrolizumab who were enrolled in a phase II basket trial in advanced, rare solid tumors (ClinicalTrials.gov: NCT02721732). Cases We identified 5 patients with recurrent GCT (4 adult and 1 juvenile type); they had an extensive history of systemic therapy at study enrollment (range, 3-10), with most regimens resulting in less than 12 months of disease control. Pembrolizumab was administered in these patients, as per trial protocol. Although there were no objective responses according to the irRECIST guidelines, 2 patients with adult-type GCT experienced disease control for ≥ 12 months (565 and 453 days). In one, pembrolizumab represented the longest duration of disease control compared to prior lines of systemic therapy (565 days vs. 13 months). In the other, pembrolizumab was the second longest systemic therapy associated with disease control (453 days vs. 22 months) compared to prior lines of therapy. In this patient, pembrolizumab was discontinued following withdrawal of consent. PD-L1 expression was not observed in any baseline tumor samples. Pembrolizumab was well tolerated, with no grade 3 or 4 treatment-related adverse events. Conclusions Although our results do not support the routine use of pembrolizumab monotherapy in unselected GCT patients, some patients with adult-type GCT may derive a clinical benefit, with a low risk of toxicity. Future studies should investigate the role of immunotherapy and predictors of clinical benefit in this patient population.

Pembrolizumab in vaginal and vulvar squamous cell carcinoma: a case series from a phase II basket trial

AbstractVaginal and vulvar squamous cell carcinoma (SCC) are rare tumors that can be challenging to treat in the recurrent or metastatic setting. We present a case series of patients with vaginal or vulvar SCC who were treated with single-agent pembrolizumab as part of a phase II basket clinical trial to evaluate efficacy and safety. Two cases of recurrent and metastatic vaginal SCC, with multiple prior lines of systemic chemotherapy and radiation, received pembrolizumab. One patient had significant reduction (81%) in target tumor lesions prior to treatment discontinuation at cycle 10 following confirmed progression of disease with new metastatic lesions (stable disease by irRECIST criteria). In contrast, the other patient with vaginal SCC discontinued treatment after cycle 3 due to disease progression. Both patients had PD-L1 positive vaginal tumors and tolerated treatment well. One case of recurrent vulvar SCC with multiple surgical resections and prior progression on systemic carboplatin had a 30% reduction in her target tumor lesions following pembrolizumab treatment with a PD-L1 positive tumor. Treatment was discontinued for grade 3 mucositis after cycle 5. Pembrolizumab may provide some clinical benefit to some patients with vaginal or vulvar SCC and is overall safe to utilize in this population. Future studies are needed to evaluate the efficacy of pembrolizumab in these rare tumor types and to identify predictive biomarkers of response.