Patients' selection and trial matching in early-phase oncology clinical trials

BACKGROUND

Early-phase clinical trials (EPCT) represent an important part of innovations in medical oncology and a valuable therapeutic option for patients with metastatic cancers, particularly in the era of precision medicine. Nevertheless, adult patients' participation in oncology clinical trials is low, ranging from 2% to 8% worldwide, with unequal access, and up to 40% risk of early discontinuation in EPCT, mostly due to cancer-related complications.

DESIGN

We review the tools and initiatives to increase patients' orientation and access to early phase cancer clinical trials, and to limit early discontinuation.

RESULTS

New approaches to optimize the early-phase clinical trial referring process in oncology include automatic trial matching, tools to facilitate the estimation of patients' prognostic and/or to better predict patients' eligibility to clinical trials. Classical and innovative approaches should be associated to double patient recruitment, improve clinical trial enrollment experience and reduce early discontinuation rates.

CONCLUSIONS

Whereas EPCT are essential for patients to access the latest medical innovations in oncology, offering the appropriate trial when it is relevant for patients should increase by organizational and technological innovations. The oncologic community will need to closely monitor their performance, portability and simplicity for implementation in daily clinical practice.

Health-related quality of life with pembrolizumab monotherapy in patients with previously treated advanced microsatellite instability high/mismatch repair deficient endometrial cancer in the KEYNOTE-158 study

OBJECTIVE

Pembrolizumab demonstrated a clinically meaningful objective response rate in patients with previously treated, advanced MSI-H/dMMR endometrial cancer in the multicohort phase 2 KEYNOTE-158 study (ClinicalTrials.gov, NCT02628067). We present health-related quality of life (HRQoL) results for these patients.

METHODS

This analysis included patients from cohorts D (endometrial cancer with any MSI status) and K (any MSI-H/dMMR solid tumor except colorectal) who had previously treated, advanced MSI-H/dMMR endometrial cancer. Patients received pembrolizumab 200 mg Q3W for 35 cycles. EORTC QLQ-C30 and EQ-5D-3L questionnaires were administered at baseline, at regular intervals during treatment, and 30 days after treatment discontinuation. Pre-specified exploratory analyses included changes from baseline to week 9 in QLQ-C30 global health status (GHS)/QoL and EQ-5D-3L visual analog scale (VAS) score for all patients and by best overall response.

RESULTS

84 of 90 enrolled patients completed ≥1 HRQoL questionnaire and were included in the analysis. QLQ-C30 and EQ-5D-3L compliance rates were 90% and 94%, respectively, at baseline, and 92% and 93% at week 9. Mean (95% CI) QLQ-C30 GHS/QoL scores improved from baseline to week 9 by 6.08 (0.71-11.46) points in the overall population, with greater improvement in patients who achieved complete or partial response (11.67 [5.33-18.00]-point increase). Mean (95% CI) EQ-5D-3L VAS scores improved by 6.00 (2.25-9.75) points in the overall population and 9.11 (5.24-12.98) points in patients with CR/PR.

CONCLUSIONS

Pembrolizumab maintained or improved HRQoL in patients with previously treated, advanced MSI-H/dMMR endometrial cancer, further supporting efficacy and safety results from KEYNOTE-158 and pembrolizumab use in this setting.

Immune checkpoint inhibitor-based combinations: is dose escalation mandatory for phase I trials?

BACKGROUND

Numerous phase I trials testing immune checkpoint inhibitors (CPI)-based combinations are currently being conducted to improve response rates observed with single agents. However, methodology varies across studies, especially regarding the use of dose escalation.

MATERIALS AND METHODS

A literature search was conducted in Pubmed and major oncology meetings libraries for phase I trials reported between 2011 and 2018, containing at least one CPI [CLTA-4 blocking antibody or a PD(L)1 blocking antibody] plus at least one second agent (e.g. tyrosine kinase inhibitor, chemotherapy). Dose escalation schemes, target doses and recommended phase II doses (RP2D) were captured in our database for each study. Combination RP2D (combo-RP2D) was compared with target dose.

RESULTS

We identified 113 different studies comprising a total of 120 individual cohorts. The backbone was an anti- cytotoxic T-lymphocyte antigen 4 (CTLA-4) in 40 cohorts and an anti-PD(L)1 in 80 cohorts. Dose escalation was used for the CPI in 29 (24%) cohorts [11% for anti-PD(L)1 and 50% for anti-CTLA-4] and for the second agent in 55 cohorts (46%). For 31 s agents (26%), the combo-RP2D was significantly lower than the expected target dose. Failure to reach the target dose was explained by the type of second agent form (e.g. small molecules versus monoclonal antibodies) (P < 0.001) and the choice of trial design for the second agent by investigators.

CONCLUSION

Design of studies investigating new CPI-based combinations must consider the type of second agent. Dose escalation is required for combinations with small molecules but is unnecessary with vaccine/virus/dendritic therapies and monoclonal antibodies.

Phase I study of emactuzumab single agent or in combination with paclitaxel in patients with advanced/metastatic solid tumors reveals depletion of immunosuppressive M2-like macrophages

BACKGROUND

Emactuzumab is a monoclonal antibody against the colony-stimulating factor-1 receptor and targets tumor-associated macrophages (TAMs). This study assessed the safety, clinical activity, pharmacokinetics (PK) and pharmacodynamics (PD) of emactuzumab, as monotherapy and in combination with paclitaxel, in patients with advanced solid tumors.

PATIENTS AND METHODS

This open-label, phase Ia/b study comprised two parts (dose escalation and dose expansion), each containing two arms (emactuzumab, every 2 or 3 weeks, as monotherapy or in combination with paclitaxel 80 mg/m2 weekly). The dose-escalation part explored the maximum tolerated dose and optimal biological dose (OBD). The dose-expansion part extended the safety assessment and investigated the objective response rate. A PK/PD analysis of serial blood, skin and tumor biopsies was used to explore proof of mechanism and confirm the OBD.

RESULTS

No maximum tolerated dose was reached in either study arm, and the safety profile of emactuzumab alone and in combination does not appear to preclude its use. No patients receiving emactuzumab monotherapy showed an objective response; the objective response rate for emactuzumab in combination with paclitaxel was 7% across all doses. Skin macrophages rather than peripheral blood monocytes or circulating colony-stimulating factor-1 were identified as an optimal surrogate PD marker to select the OBD. Emactuzumab treatment alone and in combination with paclitaxel resulted in a plateau of immunosuppressive TAM reduction at the OBD of 1000 mg administered every 2 weeks.

CONCLUSIONS

Emactuzumab showed specific reduction of immunosuppressive TAMs at the OBD in both treatment arms but did not result in clinically relevant antitumor activity alone or in combination with paclitaxel. (ClinicalTrials.gov Identifier: NCT01494688).

Adjuvant radiotherapy for extremity and trunk wall atypical lipomatous tumor/well-differentiated LPS (ALT/WD-LPS): a French Sarcoma Group (GSF-GETO) study

BACKGROUND

The role of adjuvant radiotherapy (RT) in the management of atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WD-LPS) remains controversial.

METHODS

Two hundred eighty-three patients with operable ALT/WD-LPS, no history of previous cancer, chemotherapy (CT) or RT, treated between 1984 and 2011 registered in the Conticabase database were included and described. Overall (OS), progression-free survival (PFS) and time to local relapse (TTLR) were evaluated from the time of first treatment.

RESULTS

Three of 20 centers enrolled 58% of the patients. Median age at diagnosis was 61 (range 25-94) years, 147 patients (52%) were males, 222 (78%) patients had their primary tumor located in an extremity while 36 (13%) and 25 (9%) had tumors involving the girdle and the trunk wall, respectively. The median size of primary tumors was 17 cm (range 2-48 cm). Adjuvant RT was given to 132 patients (47%). Patients who received adjuvant RT had larger tumors (P = 0.005), involving more often the distal limbs (P < 0.001). Use of adjuvant RT varied across centers and along the study period. Other characteristics were balanced between the two groups. Median follow-up was 61.7 months. None of the patients developed metastasis during follow-up. The 5-year local relapse-free survival rates were 98.3% versus 80.3% with and without adjuvant RT, respectively (P < 0.001). Once stratified on time period (before/after 2003), adjuvant RT, tumor site and margin status (R0 versus other) were independently associated with TTLR. No OS difference was observed (P = 0.105).

CONCLUSION

In this study, adjuvant RT following resection of ALT/WD-LPS was associated with a reduction of LR risk.

Outcome of patients with sarcoma and other mesenchymal tumours participating in phase I trials: a subset analysis of a European Phase I database

BACKGROUND

Although sarcomas account for only 1% of all solid tumours, patients with sarcomas comprise a larger proportion of patients entering phase I trials, due to the limited number of registered or active drugs for these diseases. To help in patient selection, we evaluated the utility of the predictive Royal Marsden Score which had been derived in carcinoma patients. In addition, we analysed efficacy and toxicity regarding the sarcoma population enrolled in phase I trials.

PATIENTS AND METHODS

We used data from a European Database comprising 2182 patients treated in phase I trials in 14 European institutions between 2005 and 2007.

RESULTS

One hundred and seventy-eight patients diagnosed with advanced sarcoma or other mesenchymal tumours were identified and accounted for 217 phase I trial participations during the study period. Histological type, class of drug, number of metastatic sites, high serum lactate dehydrogenase activity (LDH), low albumin and high white blood cell count were independent prognostic factors. Poor performance status (PS), liver metastases and high leucocyte count were associated with increased risk of early death. The class of drug used was the strongest predictor of progression-free survival (PFS) duration, inhibitors of angiogenesis and histone deacetylase giving the best results. Poor PS, high serum LDH and low lymphocyte count correlated with shorter PFS. In this heterogeneous population, PFS with investigational agents appeared comparable with that previously published for patients receiving standard treatments beyond first line.

CONCLUSION

Prognostic factors in sarcoma patients do not differ from a broader phase I population. Efficacy measures suggest that some patients with sarcoma derive benefit from therapy in this setting which could therefore be considered for patients with no remaining standard therapeutic option.

A phase II trial of panobinostat in patients with advanced pretreated soft tissue sarcoma. A study from the French Sarcoma Group

Background:

Soft tissue sarcomas (STS) are rare tumours for which treatment options are limited in the advanced setting. Histone deacetylase inhibitors have shown activity in preclinical models of STS.

Methods:

We conducted a single-arm, open-label, multicentre phase II study to assess the efficacy and tolerability of panobinostat given orally, 40 mg thrice weekly in patients with advanced pretreated STS. The primary endpoint was the 3-month progression-free rate.

Results:

Forty-seven STS patients were enrolled between January 2010 and December 2010. Median age was 59 (range 21–79) years, 22 (47%) patients were males. Panobinostat dose was lowered to 20 mg thrice weekly after nine patients were enrolled, based on the recommendation of an independent safety committee. The most common grade 3/4 adverse events were thrombocytopenia, fatigue, lymphopenia and anaemia. Forty-five patients were evaluable for the primary endpoint. Among them, nine patients (20%, 95% CI (10–35%)) were progression-free at 3 months. No partial response was seen, but 17 patients (36%) had stable disease (SD) as their best response. Six patients were progression-free at 6 months.

Conclusion:

Panobinostat was poorly tolerated at 40 mg thrice a week. Efficacy in unselected advanced STS was limited, although some patients had prolonged SD.

Neoadjuvant imatinib in patients with locally advanced GIST in the prospective BFR14 trial

10551

Background: The role of surgery in the management of patients with advanced gastrointestinal stromal tumors (GIST) in the era of imatinib mesylate (IM) remains unknown. We sought to assess the outcome of patients with locally advanced primary GIST tumors without metastases treated with IM in the neoadjuvant setting within the prospective BFR14 phase III trial. Methods: The data base of the BFR14 trial was searched for patients with locally advanced disease and no metastases. Patients with recurrent disease were excluded. Results: Twenty five patients (9 females, 16 males) met these criteria. Twenty patients were PS 0 or 1, primary tumor sites were: small intestine (n=7), peritoneum (n=7), rectum (n=4), stomach (n=4), esophagus (n=2), and pelvis (n=1). Nine of the 25 patients underwent surgical resection of the primary tumor after a median of 7.3 (range 3.4–12.1) months of treatment with IM. There was a significant improvement in progression-free survival (PFS) for patient who underwent surgical resection versus those who did not: median PFS: 28.7 month vs 12.9 months respectively (p=0.0463) this benefit did not however translate into a significant benefit in overall survival (OS), although the trend favoured the resected group: median OS median not reached vs 29.4 months (p=0.0677). Conclusions: Surgery may increase progression-free survival in patients with locally advanced GIST who become resectable following treatment with IM.

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