Efficacy and safety of pembrolizumab in metastatic urothelial carcinoma: results from KEYNOTE-045 and KEYNOTE-052 after up to 5 years of follow-up

BACKGROUND

Immune checkpoint inhibitors are a standard therapy in metastatic urothelial carcinoma (UC). Long-term follow-up is necessary to confirm durability of response and identify further safety concerns.

PATIENTS AND METHODS

In KEYNOTE-045, patients with metastatic UC that progressed on platinum-containing chemotherapy were randomly assigned 1:1 to receive pembrolizumab or investigator's choice of paclitaxel, docetaxel, or vinflunine. Primary endpoints were progression-free survival per RECIST version 1.1 by blinded independent central review (BICR) and overall survival. In KEYNOTE-052, cisplatin-ineligible patients with metastatic UC received first-line pembrolizumab. The primary endpoint was objective response rate per RECIST version 1.1 by BICR.

RESULTS

A total of 542 patients (pembrolizumab, n = 270; chemotherapy, n = 272) were randomly assigned in KEYNOTE-045. The median follow-up was 62.9 months (range 58.6-70.9 months; data cut-off 1 October 2020). At 48 months, overall survival rates were 16.7% for pembrolizumab and 10.1% for chemotherapy; progression-free survival rates were 9.5% and 2.7%, respectively. The median duration of response (DOR) was 29.7 months (range 1.6+ to 60.5+ months) for pembrolizumab and 4.4 months (range 1.4+ to 63.1+ months) for chemotherapy; 36-month DOR rates were 44.4% and 28.3%, respectively. A total of 370 patients were enrolled in KEYNOTE-052. The median follow-up was 56.3 months (range 51.2-65.3 months; data cut-off 26 September 2020). The confirmed objective response rate was 28.9% (95% confidence interval 24.3-33.8), and the median DOR was 33.4 months (range 1.4+ to 60.7+ months); the 36-month DOR rate was 44.8%. Most treatment-related adverse events for pembrolizumab in either study were grade 1 or 2 and manageable, which is consistent with prior reports.

CONCLUSION

With ∼5 years of follow-up, pembrolizumab monotherapy continued to demonstrate durable efficacy with no new safety signals in patients with platinum-resistant metastatic UC and as first-line therapy in cisplatin-ineligible patients.

CLINICAL TRIAL REGISTRY AND ID

With ClinicalTrials.gov NCT02256436 (KEYNOTE-045); https://clinicaltrials.gov/ct2/show/NCT02256436 and NCT02335424 (KEYNOTE-052); https://clinicaltrials.gov/ct2/show/NCT02335424.

Ibrutinib in combination with nab-paclitaxel and gemcitabine for first-line treatment of patients with metastatic pancreatic adenocarcinoma: phase III RESOLVE study

BACKGROUND

First-line treatment of metastatic pancreatic ductal adenocarcinoma (PDAC) includes nab-paclitaxel/gemcitabine. Ibrutinib, a Bruton's tyrosine kinase inhibitor, exhibits antitumor activity through tumor microenvironment modulation. The safety and efficacy of first-line ibrutinib plus nab-paclitaxel/gemcitabine treatment in patients with PDAC were evaluated.

PATIENTS AND METHODS

RESOLVE (NCT02436668) was a phase III, randomized, double-blind, placebo-controlled study. Patients (histologically-confirmed PDAC; stage IV diagnosis ≥6 weeks of randomization; Karnofsky performance score ≥70) were randomized to once-daily oral ibrutinib (560 mg) or placebo plus nab-paclitaxel (125 mg/m²) and gemcitabine (1000 mg/m²). Primary endpoints were overall survival (OS) and investigator-assessed progression-free survival (PFS); overall response rate and safety were assessed.

RESULTS

In total, 424 patients were randomized (ibrutinib arm, n = 211; placebo arm, n = 213). Baseline characteristics were balanced across arms. After a median follow-up of 25 months, there was no significant difference in OS between ibrutinib plus nab-paclitaxel/gemcitabine versus placebo plus nab-paclitaxel/gemcitabine (median of 9.7 versus 10.8 months; P = 0.3225). PFS was shorter for ibrutinib plus nab-paclitaxel/gemcitabine compared with placebo plus nab-paclitaxel/gemcitabine (median 5.3 versus 6.0 months; P < 0.0001). Overall response rates were 29% and 42%, respectively (P = 0.0058). Patients in the ibrutinib arm had less time on treatment and received lower cumulative doses for all agents compared with the placebo arm. The most common grade ≥3 adverse events for ibrutinib versus placebo arms included neutropenia (24% versus 35%), peripheral sensory neuropathy (17% versus 8%), and anemia (16% versus 17%). Primary reasons for any treatment discontinuation were disease progression and adverse events.

CONCLUSIONS

Ibrutinib plus nab-paclitaxel/gemcitabine did not improve OS or PFS for patients with PDAC. Safety was consistent with known profiles for these agents.

Randomized phase III KEYNOTE-045 trial of pembrolizumab versus paclitaxel, docetaxel, or vinflunine in recurrent advanced urothelial cancer: results of >2 years of follow-up

Background

Novel second-line treatments are needed for patients with advanced urothelial cancer (UC). Interim analysis of the phase III KEYNOTE-045 study showed a superior overall survival (OS) benefit of pembrolizumab, a programmed death 1 inhibitor, versus chemotherapy in patients with advanced UC that progressed on platinum-based chemotherapy. Here we report the long-term safety and efficacy outcomes of KEYNOTE-045.

Patients and methods

Adult patients with histologically/cytologically confirmed UC whose disease progressed after first-line, platinum-containing chemotherapy were enrolled. Patients were randomly assigned 1 : 1 to receive pembrolizumab [200 mg every 3 weeks (Q3W)] or investigator’s choice of paclitaxel (175 mg/m² Q3W), docetaxel (75 mg/m² Q3W), or vinflunine (320 mg/m² Q3W). Primary end points were OS and progression-free survival (PFS) per Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST v1.1) by blinded independent central radiology review (BICR). A key secondary end point was objective response rate per RECIST v1.1 by BICR.

Results

A total of 542 patients were enrolled (pembrolizumab, n = 270; chemotherapy, n = 272). Median follow-up as of 26 October 2017 was 27.7 months. Median 1- and 2-year OS rates were higher with pembrolizumab (44.2% and 26.9%, respectively) than chemotherapy (29.8% and 14.3%, respectively). PFS rates did not differ between treatment arms; however, 1- and 2-year PFS rates were higher with pembrolizumab. The objective response rate was also higher with pembrolizumab (21.1% versus 11.0%). Median duration of response to pembrolizumab was not reached (range 1.6+ to 30.0+ months) versus chemotherapy (4.4 months; range 1.4+ to 29.9+ months). Pembrolizumab had lower rates of any grade (62.0% versus 90.6%) and grade ≥3 (16.5% versus 50.2%) treatment-related adverse events than chemotherapy.

Conclusions

Long-term results (>2 years’ follow-up) were consistent with those of previously reported analyses, demonstrating continued clinical benefit of pembrolizumab over chemotherapy for efficacy and safety for treatment of locally advanced/metastatic, platinum-refractory UC.

Trial registration

ClinicalTrials.gov: NCT02256436.

Intratumoral delivery of tavokinogene telseplasmid yields systemic immune responses in metastatic melanoma patients

BACKGROUND

Interleukin 12 (IL-12) is a pivotal regulator of innate and adaptive immunity. We conducted a prospective open-label, phase II clinical trial of electroporated plasmid IL-12 in advanced melanoma patients (NCT01502293).

PATIENTS AND METHODS

Patients with stage III/IV melanoma were treated intratumorally with plasmid encoding IL-12 (tavokinogene telseplasmid; tavo), 0.5 mg/ml followed by electroporation (six pulses, 1500 V/cm) on days 1, 5, and 8 every 90 days in the main study and additional patients were treated in two alternative schedule exploration cohorts. Correlative analyses for programmed death-ligand 1 (PD-L1), flow cytometry to assess changes in immune cell subsets, and analysis of immune-related gene expression were carried out on pre- and post-treatment samples from study patients, as well as from additional patients treated during exploration of additional dosing schedules beyond the pre-specified protocol dosing schedule. Response was measured by study-specific criteria to maximize detection of latent and potentially transient immune responses in patients with multiple skin lesions and toxicities were graded by the Common Terminology Criteria for Adverse Events version 4.0 (CTCAE v4.0).

RESULTS

The objective overall response rate was 35.7% in the main study (29.8% in all cohorts), with a complete response rate of 17.9% (10.6% in all cohorts). The median progression-free survival in the main study was 3.7 months while the median overall survival was not reached at a median follow up of 29.7 months. A total of 46% of patients in all cohorts with uninjected lesions experienced regression of at least one of these lesions and 25% had a net regression of all untreated lesions. Transcriptomic and immunohistochemistry analysis showed that immune activation and co-stimulatory transcripts were up-regulated but there was also increased adaptive immune resistance.

CONCLUSIONS

Intratumoral Tavo was well tolerated and led to systemic immune responses in advanced melanoma patients. While tumor regression and increased immune infiltration were observed in treated as well as untreated/distal lesions, adaptive immune resistance limited the response.

Predictors of responses to immune checkpoint blockade in advanced melanoma

Immune checkpoint blockers (ICB) have become pivotal therapies in the clinical armamentarium against metastatic melanoma (MMel). Given the frequency of immune related adverse events and increasing use of ICB, predictors of response to CTLA-4 and/or PD-1 blockade represent unmet clinical needs. Using a systems biology-based approach to an assessment of 779 paired blood and tumor markers in 37 stage III MMel patients, we analyzed association between blood immune parameters and the functional immune reactivity of tumor-infiltrating cells after ex vivo exposure to ICB. Based on this assay, we retrospectively observed, in eight cohorts enrolling 190 MMel patients treated with ipilimumab, that PD-L1 expression on peripheral T cells was prognostic on overall and progression-free survival. Moreover, detectable CD137 on circulating CD8⁺ T cells was associated with the disease-free status of resected stage III MMel patients after adjuvant ipilimumab + nivolumab (but not nivolumab alone). These biomarkers should be validated in prospective trials in MMel.The clinical management of metastatic melanoma requires predictors of the response to checkpoint blockade. Here, the authors use immunological assays to identify potential prognostic/predictive biomarkers in circulating blood cells and in tumor-infiltrating lymphocytes from patients with resected stage III melanoma.

Effects of Information Access Cost and Accountability on Medical Residents' Information Retrieval Strategy and Performance During Prehandover Preparation: Evidence From Interview and Simulation Study

OBJECTIVE

We aimed to examine the effects of information access cost and accountability on medical residents' information retrieval strategy and performance during prehandover preparation.

BACKGROUND

Prior studies observing doctors' prehandover practices witnessed the use of memory-intensive strategies when retrieving patient information. These strategies impose potential threats to patient safety as human memory is prone to errors. Of interest in this work are the underlying determinants of information retrieval strategy and the potential impacts on medical residents' information preparation performance.

METHOD

A two-step research approach was adopted, consisting of semistructured interviews with 21 medical residents and a simulation-based experiment with 32 medical residents.

RESULTS

The semistructured interviews revealed that a substantial portion of medical residents (38%) relied largely on memory for preparing handover information. The simulation-based experiment showed that higher information access cost reduced information access attempts and access duration on patient documents and harmed information preparation performance. Higher accountability led to marginally longer access to patient documents.

CONCLUSION

It is important to understand the underlying determinants of medical residents' information retrieval strategy and performance during prehandover preparation. We noted the criticality of easy access to patient documents in prehandover preparation. In addition, accountability marginally influenced medical residents' information retrieval strategy.

APPLICATION

Findings from this research suggested that the cost of accessing information sources should be minimized in developing handover preparation tools.

The effect of information access cost and overconfidence bias on junior doctors’ pre-handover performance

This paper examined the effect of information access cost and overconfidence bias on doctors’ information retrieval strategies and performances during pre-handover. Sixteen medical residents participated in a simulated experiment, where they studied four patient cases and later on completed recall and recognition questions. The results showed that an increase in information access cost led to less information access attempts and poorer pre-handover performance. Further, there was an interaction between information access cost and overconfidence on pre-handover performance. When information access cost was high, overconfidence contributed to poor pre-handover performance.

A phase 1 trial of imatinib, bevacizumab, and metronomic cyclophosphamide in advanced colorectal cancer

Background:

This phase 1 clinical trial was conducted to determine the safety, maximum-tolerated dose (MTD), and pharmacokinetics of imatinib, bevacizumab, and metronomic cyclophosphamide in patients with advanced colorectal cancer (CRC).

Methods:

Patients with refractory stage IV CRC were treated with bevacizumab 5 mg kg⁻¹ i.v. every 2 weeks (fixed dose) plus oral cyclophosphamide q.d. and imatinib q.d. or b.i.d. in 28-day cycles with 3+3 dose escalation. Response was assessed every two cycles. Pharmacokinetics of imatinib and cyclophosphamide and circulating tumour, endothelial, and immune cell subsets were measured.

Results:

Thirty-five patients were enrolled. Maximum-tolerated doses were cyclophosphamide 50 mg q.d., imatinib 400 mg q.d., and bevacizumab 5 mg kg⁻¹ i.v. every 2 weeks. Dose-limiting toxicities (DLTs) included nausea/vomiting, neutropaenia, hyponatraemia, fistula, and haematuria. The DLT window required expansion to 42 days (1.5 cycles) to capture delayed toxicities. Imatinib exposure increased insignificantly after adding cyclophosphamide. Seven patients (20%) experienced stable disease for >6 months. Circulating tumour, endothelial, or immune cells were not associated with progression-free survival.

Conclusion:

The combination of metronomic cyclophosphamide, imatinib, and bevacizumab is safe and tolerable without significant drug interactions. A subset of patients experienced prolonged stable disease independent of dose level.

A phase I study of sorafenib and RAD001 for metastatic clear cell renal cell carcinoma

5104

Background: Both RAD001 and sorafenib have activity against advanced clear cell renal cell carcinoma (ccRCC). Inhibition of both mTOR and angiogenesis may improve outcomes; therefore, a phase I trial combining sorafenib and RAD001 was undertaken. Methods: Cohorts of 3 or 6 patients with ccRCC were treated with a 7 day run-in period of sorafenib 400 mg PO BID continuously followed by RAD001 (dose level I: 2.5 mg, dose level II: 5 mg) PO QD and sorafenib 400 mg PO BID continuously. Pharmacokinetic sampling of sorafenib was obtained on day -1, and of both RAD001 and sorafenib on day 15 of combination therapy. Dose-limiting toxicity (DLT) was defined as occurring within the first 28 days of therapy. Results: Fifteen patients with a median age of 65 (range 51–75) have been enrolled. Two patients were not evaluable for response or DLT evaluation. Five pts were treated with sunitinib previously. Zero of 6 pts on dose level 1 experienced a DLT. Two of 9 pts treated at dose level II have experienced protocol-defined DLTs (grade 4 uric acid and grade 3 lipase with grade 2 pancreatitis). Independently-reviewed best objective responses in 13 evaluable pts include 3 confirmed partial responses (10, 17+, and 23+ months), 6 stable disease (2+, 4+, 4.5, 6+, 13, and 23+ months), and 4 progressive disease. Steady state dosing of RAD001 demonstrated a steady state AUC0–24h of RAD001 of 193.3 (± 32.9) ng h/mL at a dosage of 5 mg QD, comparable to the single agent 5 mg QD steady state dosing AUC0–24h of 238 (± 77) ng h/mL, suggesting there is no pharmacokinetic interaction between RAD001 and sorafenib. Linear pharmacokinetics between the 2.5 and 5 mg QD dosages of RAD001 were observed. The AUC0–24h of sorafenib was not significantly changed by concomitant dosing with RAD001 with a steady state AUC0–24h of 134600 (±42072) ng h/mL pre-RAD001 and a post-sorafenib steady state AUC0–24h of 131451 (±53838) ng h/mL. Conclusions: Combination therapy with sorafenib and RAD001 is safe and feasible. No clinically relevant pharmacokinetic interaction was observed. Activity for the combination has been observed and a phase II study is planned at the 5 mg QD dosage of RAD001.

No significant financial relationships to disclose.

A phase II study of the anti-CTLA4 monoclonal antibody (mAb), CP-675,206, in patients with refractory metastatic adenocarcinoma of the colon or rectum

3035

Background: The antitumor activity of antibodies to cytotoxic T lymphocyte-associated antigen 4 (CTLA4) has been demonstrated in a variety of murine tumor models, including rejection of established tumors and secondary exposure to tumor cells. This suggests that blockade of the inhibitory effects of CTLA4 can promote effective antitumor immune responses. CP-675,206 has also been shown to induce durable tumor responses in patients (pts) with metastatic melanoma in phase 1 and phase 2 clinical studies. The purpose of this study was to assess safety and efficacy of CTLA4 blockade with the fully human mAb CP-675,206 as single-agent therapy in pts with relapsed/ refractory colorectal cancer. Methods: A single-arm, multicenter, phase II trial of CP-675,206 was conducted in pts with measurable adenocarcinoma of the colon or rectum failing standard treatments and with an ECOG performance status of 0 or 1. Patients received 15 mg/kg Q90 days via IV infusion until disease progression. The primary objective was response rate by RECIST criteria. Secondary objectives included safety, duration of response, progression-free survival, and overall survival. Results: A total of 47 pts who received a median of 4 previous therapies (range, 1 to 9) were treated, and 46 experienced disease progression or death because of disease before reaching the planned second dose at 3 months. Grade 3 or 4 adverse events attributed to study drug were limited to diarrhea (n = 3, 6.4%) and idiopathic thrombocytopenia purpura (n = 1, 2.1%). Four pts (8.5%) had grade 2 diarrhea. Four pts received steroids and 2 received infliximab. One patient was removed for toxicity (diarrhea in the setting of what appeared to be treatment-related ulcerative colitis that was responsive to steroids). One patient (2%; 95% CI = 0%, 11%) had a stable ovarian mass and a substantial regression in an adrenal mass. This patient is continuing on study and has received a second dose. Conclusions: In heavily pretreated pts with colorectal cancer and good performance status, CP- 675,206 was tolerable. However, in this setting, CP-675,206 at 15 mg/kg did not demonstrate substantial single-agent activity.

No significant financial relationships to disclose.

Combination immunotherapy with GM-CSF and CTLA-4 blockade for hormone refractory prostate cancer: Balancing the expansion of activated effector and regulatory T cells

3001

Background: CTLA-4 is a costimulatory molecule expressed on activated T cells that delivers an inhibitory signal to these T cells. CTLA4 blockade with antibody treatment has been shown to augment T cell responses and anti-tumor immunity in animal models. Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a bone marrow growth factor for antigen presenting cells, which has also been shown to enhance anti-tumor immune responses. Methods: A phase I trial in patients with metastatic, hormone refractory prostate cancer (HRPC) was undertaken to combine these immunotherapies. Sequential cohorts of 3–6 patients were treated with escalating doses (0.5, 1.5 or 3 mg/kg) of ipilimumab, a fully human anti-CTLA-4 antibody, given IV on day 1 of each 28-day cycle × 4 cycles. Patients also received GM-CSF 250 mg/m2/d SC on days 1–14 of the 28-day cycles. Patients were monitored for toxicity as well as for T cell activation. PSA and radiographic tests were performed at baseline and through therapy to evaluate for clinical response. Results: 24 patients have been treated. Of 6 patients treated on the highest dose level (3 mg/kg ×4), 3 (50%) had confirmed PSA declines of >50%, and one of these patients had a partial response in hepatic metastases. Immune-related adverse events associated with ipilimumab treatment consisted of a grade 3 rash in 1 patient at 1.5 mg/kg, a grade 3 rash and panhypopituitarism in 1 patient at 3.0 mg/kg, and a grade 3 colitis in one patient at 3.0 mg/kg. All events were successfully managed. A dose-response relationship was seen between ipilimumab dose and effector T cell activation. Expansion of circulating CD4+ FoxP3+ regulatory T cells was also seen with treatment. Conclusions: CTLA-4 blockade combined with GM-CSF treatment induces clinical responses in HRPC. Treatment induces both the expansion of activated effector and regulatory T cells in vivo in cancer patients. Finally, CD4 and CD8 T cell activation, adverse events, and clinical responses appear to be dose-dependant. Supported by NIH SPORE P50 CA89520.

No significant financial relationships to disclose.

A phase I trial of combination immunotherapy with CTLA-4 blockade and GM-CSF in hormone-refractory prostate cancer

2508

Background: CTLA-4 is an costimulatory molecule expressed on activated T cells that delivers an inhibitory signal to these T cells. CTLA-4 blockade with antibody treatment augments T cell responses and anti-tumor immunity in animal models. Clinical trials with anti-CTLA-4 antibody treatment have demonstrated clinical responses in different malignancies including melanoma and hormone-refractory prostate cancer (HRPC). We have also shown that administration of granulocyte-macrophage colony-stimulating factor (GM-CSF) can also induce PSA declines in HRPC patients, presumably through enhancing presentation of endogenous antigens. The current study examines whether combining systemic GM-CSF to CTLA-4 blockade can augment immune and/or clinical responses in HRPC patients. Methods: In a phase I trial of patients with metastatic HRPC, sequential cohorts of 3–6 patients received GM-CSF (sargramostim, Berlex) 250 mg/m2/d SC on days 1–14 of a 28-day cycle with escalating doses (0.5, 1.5 or 3 mg/kg) of ipilimumab (MDX-010), a fully human anti-CTLA antibody (Medarex/BMS), given IV on day 1 of each cycle x 4 cycles. Patients were monitored for toxicity as well as for T cell activation. PSA and radiographic tests were performed at baseline and through therapy to evaluate for clinical response. Results: 18 patients were accrued. Ipilimumab-related dose-limiting toxicity was limited to one patient with grade 3 rash at the 3 mg/kg priming dose level. Seven patients had <50% declines in their serum PSA levels. A dose response relationship was seen between ipilimumab dose and activation of both CD4 and CD8 T cells in the blood. These effects were increased compared to effects seen with ipilimumab treatment alone in prior studies. Interferon-gamma production and lytic activity were also enhanced in circulating antigen-specific CD8+ T cells by the combination. Conclusions: GM-CSF may enhance T cell activation induced by CTLA-4 blockade. With increasing doses of anti-CTLA-4, both CD4 and CD8 T cell activation can be detected in the blood, consistent with a dose-response relationship. Supported by the UCSF Prostate SPORE NIH P50 CA89520.

No significant financial relationships to disclose.

Twenty-month effectiveness of a non-aversive, long-term, low-cost programme for persons with persisting neurobehavioural disability

PRIMARY OBJECTIVE

To examine the effectiveness of a programme developed for persons with persisting neurobehavioural/ neuropsychiatric disorders.

RESEARCH DESIGN

Descriptive study of a programme that has a philosophy of normalization, respect, non-confrontation, positive engagement, support and functional and behavioural skill development.

METHODS AND PROCEDURES

Participants were the 40 clients admitted during the initial 20 months of operation. Prior to admission clients had recurrent placement failures secondary to behavioural disregulation and typically were housed at County or State Hospitals. An expanded version of the Overt Aggression Scale Modified for Neurorehabilitation was used to provide detailed descriptions of assaults.

MAIN OUTCOMES AND RESULTS

Over the 20-month period, 49 incidents of client-to-client aggression occurred representing a rate of 0.11 incidents per client month. Thirty-five of 40 clients remained at the end of 20 months, with only three discharges due to behaviour.

CONCLUSIONS

A long-term, stable living environment has been provided for individuals who had been intractable management problems elsewhere.