Pembrolizumab monotherapy versus chemotherapy in platinum-pretreated, recurrent or metastatic nasopharyngeal cancer (KEYNOTE-122): an open-label, randomized, phase III trial

BACKGROUND

Pembrolizumab previously demonstrated robust antitumor activity and manageable safety in a phase Ib study of patients with heavily pretreated, programmed death ligand 1 (PD-L1)-positive, recurrent or metastatic nasopharyngeal carcinoma (NPC). The phase III KEYNOTE-122 study was conducted to further evaluate pembrolizumab versus chemotherapy in patients with platinum-pretreated, recurrent and/or metastatic NPC. Final analysis results are presented.

PATIENTS AND METHODS

KEYNOTE-122 was an open-label, randomized study conducted at 29 sites, globally. Participants with platinum-pretreated recurrent and/or metastatic NPC were randomly assigned (1 : 1) to pembrolizumab or chemotherapy with capecitabine, gemcitabine, or docetaxel. Randomization was stratified by liver metastasis (present versus absent). The primary endpoint was overall survival (OS), analyzed in the intention-to-treat population using the stratified log-rank test (superiority threshold, one-sided P = 0.0187). Safety was assessed in the as-treated population.

RESULTS

Between 5 May 2016 and 28 May 2018, 233 participants were randomly assigned to treatment (pembrolizumab, n = 117; chemotherapy, n = 116); Most participants (86.7%) received study treatment in the second-line or later setting. Median time from randomization to data cut-off (30 November 2020) was 45.1 months (interquartile range, 39.0-48.8 months). Median OS was 17.2 months [95% confidence interval (CI) 11.7-22.9 months] with pembrolizumab and 15.3 months (95% CI 10.9-18.1 months) with chemotherapy [hazard ratio, 0.90 (95% CI 0.67-1.19; P = 0.2262)]. Grade 3-5 treatment-related adverse events occurred in 12 of 116 participants (10.3%) with pembrolizumab and 49 of 112 participants (43.8%) with chemotherapy. Three treatment-related deaths occurred: 1 participant (0.9%) with pembrolizumab (pneumonitis) and 2 (1.8%) with chemotherapy (pneumonia, intracranial hemorrhage).

CONCLUSION

Pembrolizumab did not significantly improve OS compared with chemotherapy in participants with platinum-pretreated recurrent and/or metastatic NPC but did have manageable safety and a lower incidence of treatment-related adverse events.

Update on safety and efficacy of a phase 1/2 of SNS-301 added to pembrolizumab in patients with advanced squamous cell carcinoma of the head and neck (SCCHN)

6029

Background: The absence of infiltrating antigen-specific CD8+ T-cells at baseline is associated with low response rates to PD-1 blockade. SCCHN tumors often exclude effector T cells, and 2nd line response rates are low (13-18%). Highly immunogenic, antigen specific antitumor vaccines may expand intratumoral CD8+ T cells, potentially increasing durable response rates to PD-1 blockade. SNS-301 is a first-in-class, bacteriophage-based immune activating agent targeting human aspartate β-hydroxylase (ASPH), a tumor associated antigen overexpressed in multiple tumor types. SNS-301 is a self-adjuvanted vaccine consisting of λ-bacteriophage engineered to express an immunogenic fragment of ASPH fused to the phage gpD coat protein. The study objectives are to evaluate safety, immunogenicity and preliminary efficacy of SNS-301 added to pembrolizumab in patients (pts) not achieving tumor reductions on PD-1 blockade alone. Methods: Intradermal SNS-301 was combined with pembrolizumab in pts with locally advanced unresectable (LA) or metastatic/recurrent (met) SCCHN with a best response of stable disease (SD) or unconfirmed progressive disease (uPD) on ongoing PD-1 blockade > 12 weeks. Pts provided pre and on-treatment biopsies to characterize the tumor microenvironment using Nanostring and multiplex immunohistochemistry (mIHC). Blood samples were collected to evaluate B and T cell responses using ELISA/ELISPOT assays. Results: As of February 4, 2021, 13 pts were enrolled. Median duration of PD-1 blockade was 48 weeks (range 14-114) at study entry. There were no DLTs & mostly Grade 1-2 unrelated adverse events. Only two related Grade 3 events were reported: rash & dehydration (also a serious adverse event). Ten pts were evaluable for efficacy: 1 pt with PD-L1 negative (neg) disease & SD on pembrolizumab monotherapy achieved a partial response (PR; -52% at 8 months), 4 pts achieved SD & 5 pts had progressive disease. Two of the pts with SD had long-lasting duration (8 & 10 months) of which the latter had PD-L1 neg disease. One pt with uPD at enrollment achieved SD for 4 months. Analyses of pre- & on-treatment biopsies from the PR pt demonstrated an increase in infiltrating CD8+ T cells, PD-L1 expression & PD-1/PD-L1 proximity measures. Nanostring analysis demonstrated increased gene expression signatures for immune cells in the PR pt that was concordant with the mIHC & clinical outcome. Conclusions: The combination of SNS-301 and pembrolizumab was well-tolerated and resulted in encouraging clinical efficacy in pts not expected to respond to PD-1 blockade alone. Translational data suggest cellular response to SNS-301 and transformation of a poorly inflamed tumor to an immunologically active tumor in a responding pt (PR). Based on these data, an additional cohort will start enrolling PD-1 blockade naïve pts with LA/met SCHNN in the front-line setting. Clinical trial information: NCT04034225.

Safety/efficacy of a phase I/II study of SNS-301 added to pembrolizumab in patients with ASPH+ locally advanced unresectable or metastatic/recurrent squamous cell carcinoma of the head and neck (SCCHN)

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Background: SNS-301 is a first-in-class immune activating agent targeting human aspartyl (asparaginyl) β-hydroxylase (ASPH). ASPH is overexpressed in +20 tumor types. SNS-301 is an inactivated λ-bacteriophage, engineered to express a highly immunogenic fragment of ASPH fused to the phage gpD coat protein, previously shown to safely and effectively generate CD4, CD8 and B cell responses in a Phase I study (NCT04034225). Anti-PD-1 antibodies such as pembrolizumab and nivolumab can induce durable clinical responses in 13-16% SCCHN patients. While ASPH is frequently expressed in SCCHN, effective de novo responses to this tumor-specific antigen may be limited due to immune tolerance. Our hypothesis is that SNS-301 will break tolerance and trigger a significant anti-ASPH T-cell immune response, which in combination with anti-PD-1 blockade, will result in improved anti-tumor responses in this difficult-to-treat patient population. Methods: This is a Phase I/II study of SNS-301 delivered intradermally in combination with pembrolizumab. The population consists of 30 patients with ASPH+ locally advanced unresectable or metastatic/recurrent SCCHN who are actively receiving pembrolizumab or nivolumab for ≥12 weeks and have a best response of stable disease (SD) or first evidence of progressive disease (PD). A safety run-in will be performed for safety and any dose limiting toxicities (DLT) using a modified rolling six design prior to proceeding to full enrollment. Patients will provide a pre-SNS-301 tumor sample, an on-treatment tumor biopsy and an optional biopsy at PD to characterize the tumor microenvironment and correlate with clinical outcomes. SNS-301 in combination with pembrolizumab is given until confirmed PD or unacceptable toxicity. Study Objectives: Safety, tolerability and anti-tumor activity such as objective response rate, duration of response, progression-free and overall survival, immune responses, tumor/immune biomarkers and their associated treatment outcome. Results: Three patients have been enrolled. There have been no DLTs. Emerging safety data includes G1 adverse events with one G1 injection site pain. Patient status includes 1 PD and 2 patients with SD of at least six weeks duration. Immunological analyses will be presented. Conclusions: Early safety/efficacy warrant further evaluation of this combination therapy. Trial will be proceeding to full enrollment after the safety run-in is completed. Clinical trial information: NCT04034225.

Clinical outcomes in patients with BRAFV600 mutant melanoma and undetectable circulating tumor DNA treated with dabrafenib and trametinib

10059

Background: Circulating tumor DNA (ctDNA) analysis has been promoted as a less-invasive surrogate assay for tumor-tissue based tumor oncogene analysis. Here, we associate detection of BRAF mutant ctDNA with PFS and OS in patients with tissue-confirmed BRAFV600 mutant melanoma enrolled in S1320, a randomized phase 2 clinical trial of continuous versus intermittent dosing of dabrafenib and trametinib. Methods: Patients with BRAFV600 melanoma received continuous therapy with dabrafenib and trametinib for 8 weeks after which patients were randomized 1:1 to proceed with intermittent treatment on a 3-week-off, 5-week-on schedule or to continue with continuous therapy. Pre-treatment blood samples were interrogated using the Guardant 360 ctDNA assay for all exons of 30 known oncogenes including BRAF and for all exons with known oncogenic mutations in the COSMIC database in 40 additional oncogenes. Clinical responses were assessed at 8-week intervals by RECIST v1.1 and PFS and OS estimates were compared using log-rank test in patients with detectable versus undetectable BRAFV600 mutant ctDNA,. Results: Somatic BRAFV600E or BRAFV600K ctDNA was detected in 34 of 50 patients with baseline (before lead-in cycle 1) blood samples available for analysis including 16 of 23 (70%) patients randomized to continuous dosing, 15 of 21 (71%) randomized to intermittent dosing, and 3 of 6 (50%) who were not randomized due to disease progression at 8 weeks or other factors. Four additional patients had other detectable somatic mutations but no detectable BRAFV600 ctDNA at baseline, and 12 patients had no detectable somatic ctDNA mutations at baseline. Detection of BRAFV600 ctDNA was associated with baseline disease stage (p = 0.008). There was no difference in the overall response rate based on baseline ctDNA detection. Detection of ctDNA at baseline was associated with worse PFS (median BRAFV600 ctDNA positive = 5.8; 95% CI: 4.2-9.6 months, BRAFV600 ctDNA negative = 21.4 mos; 95% CI 10.4-NA; measured from registration to lead-in cycle 1, p = 0.001) and OS (BRAFV600 ctDNA positive = 17.8 mos; 95% CI 9.76-NA, BRAFV600 ctDNA negative = not reached; 95% CI NA-NA, p = 0.0021). Conclusions: The absence of detectable BRAFV600 ctDNA at baseline is associated with improved PFS and OS in patients receiving treatment with dabrafenib and trametinib. Clinical trial information: NCT02196181.

Association of prior immune checkpoint blockade (ICB) with longer progression-free survival (PFS) in patients treated with intermittent versus continuous dabrafenib and trametinib: A post-hoc analysis of S1320

10039

Background: S1320 is a phase 2 randomized clinical trial presented at the 2020 AACR Annual Meeting in April demonstrating that continuous dosing of dabrafenib and trametinib yields longer PFS than intermittent dosing of these agents in patients with BRAFV600E/K melanoma. Here we look at the association between prior exposure to ICB and PFS in patients randomized to either intermittent or continuous dosing on S1320. Methods: Patients without disease progression after 8 weeks of dabrafenib and trametinib were randomized 1:1 to proceed with intermittent therapy (3-week-off, 5-week-on) or to stay on the continuous daily dosing schedule. The design called for 206 randomized patients with the primary outcome of PFS. Response assessments were made using RECIST v1.1 at 8-week intervals. A post-hoc analysis assessed differences in PFS in the pool of all randomized patients based on prior exposure to anti-PD1 antibodies, a randomization stratification factor. Kaplan-Meier estimates and multivariable Cox regression models (controlling for pre-randomization age, Zubrod performance status, LDH, unknown primary, M-Stage) were used to evaluate the association between this stratification factor and PFS. Results: Of 242 patients treated on study, 105 were randomized to continuous dosing, 101 to intermittent dosing, and 36 were not randomized due to disease progression at 8 weeks or other factors. 37% of the 242 enrolled and 37% of the 206 randomized patients had previously been treated with ICB. Among all randomized patients, there were no differences in baseline characteristics comparing patients with and without prior immune checkpoint inhibitor exposure: age median 62 vs 59, LDH elevation 37% vs 39%,, stage IVB/C 73% vs 64%, Zubrod performance status 0, 57% vs 58%. PFS was longer in patients with prior ICB exposure (hazard ratio = 0.60, 95% confidence interval 0.41,-0.98, median = 6 vs 9 months from randomization, 8 vs 11 months from starting treatment). There was no difference in the association between prior ICB exposure and PFS between arms (interaction p-value = 0.62). Conclusions: In patients without early progression on dabrafenib and trametinib, PFS was longer with prior to exposure to ICB . Although the groups had similar baseline characteristics and rates of randomization, these results could still be influenced by non-controlled factors influencing clinicians’ decisions to start a patient on immune versus targeted therapy. Clinical trial information: NCT02196181.

Efficacy and safety of the combination of nivolumab (NIVO) plus ipilimumab (IPI) in patients with symptomatic melanoma brain metastases (CheckMate 204)

9501

Background: We previously reported efficacy and safety of NIVO+IPI in patients (pts) with untreated, asymptomatic, melanoma brain metastases (MBM) from the CheckMate 204 study. Here, we provide the first report of NIVO+IPI in pts with symptomatic MBM, and report updated data in pts with asymptomatic MBM. Methods: In this phase II trial, pts with ≥1 measurable, nonirradiated MBM 0.5–3.0 cm were enrolled into two cohorts: (1) those with no neurologic symptoms or steroid Rx (asymptomatic; cohort A); and (2) those with neurologic symptoms, whether or not they were receiving steroid Rx (symptomatic; cohort B). In both cohorts, pts received NIVO 1 mg/kg + IPI 3 mg/kg Q3W × 4, then NIVO 3 mg/kg Q2W until progression or toxicity. The primary endpoint was intracranial clinical benefit rate (CBR; proportion of pts with complete response [CR] + partial response [PR] + stable disease [SD] ≥6 mo). As of the clinical cutoff date on May 1, 2018, all treated pts (101 in cohort A and 18 in cohort B) had been followed for ~6 mo or longer. Results: In this updated analysis of cohort A (median follow-up of 20.6 mo), the CBR was 58.4% (Table). In cohort B, pts received a median of 1 NIVO+IPI dose and 2 of 18 pts (11%) received all 4 doses. At a median follow-up of 5.2 months in cohort B, intracranial objective response rate was 16.7% and the CBR was 22.2%. Grade 3/4 adverse events occurred in 54.5% of pts in cohort A and in 55.6% of pts in cohort B (6.9% and 16.7% in the nervous system, respectively), with one death related to treatment in cohort A (immune-related myocarditis). Conclusions: In pts with asymptomatic MBM, our updated results show a high rate of durable intracranial responses, further supporting NIVO+IPI as a first-line treatment in this population. Intracranial antitumor activity was observed with NIVO+IPI in pts with symptomatic MBM, but further study is needed to understand the biologic mechanisms of resistance to immunotherapy and to improve treatments in this challenging population. Clinical trial information: NCT02320058. [Table: see text]

Phase 1b/2, open label, multicenter study of intratumoral SD-101 in combination with pembrolizumab in anti-PD-1 treatment naïve patients with recurrent or metastatic head and neck squamous cell carcinoma (HNSCC)

6039

Background: SD-101, a synthetic CpG-ODN agonist of TLR9, stimulates dendritic cells to release IFN-alpha and mature into antigen presenting cells - activating T cell anti-tumor responses. Pembrolizumab has demonstrated activity in HNSCC. Study DV3-MEL-01 (NCT02521870) assesses safety and efficacy of SD-101 in combination with pembrolizumab in patients with recurrent/metastatic HNSCC. We have previously reported a 27.3% ORR in 22 patients receiving 8 mg SD-101/injection in the modified ITT after at least 2 CT scans due to late responses (Abstract 3560, ESMO 2018). Higher efficacy at a lower SD-101 dose, 2 mg/injection, has been reported in advanced melanoma patients (LBA 45, ESMO 2018). Consequently, this dose is now being assessed in HNSCC. We report preliminary data with the 2 mg/injection dose in 23 patients in mITT at the first CT scan. Methods: Anti-PD-1/PD-L1 naïve patients received 2 mg SD-101 intratumorally in 1 - 4 lesions (weekly x 4 doses then Q3W x 7 doses). Pembrolizumab is was administered IV at 200 mg Q3W. Responses were assessed per RECIST v1.1. Results: 28 patients enrolled: median age 63 y/o, male 68%; ECOG PS 0-1 (18%/82%); mean prior lines of systemic therapy 1 (0-3); mean treatment duration 70 days (1-253). Primary tumors: 19 (68%) oropharyngeal; 3 (10%) laryngeal; 2 (7%) hypopharyngeal; 4 (14%) unknown. Mean number of target lesions: 1.82 (1 to 5). HPV status: 7 (25%) +, 9 (32%) -, 12 (43%) unknown. 18 (64 %) discontinued treatment: 12 (42%) due to PD, 4 (16%) deaths, 1 (3%) consent withdrawn, 1 (3%) went to hospice. Mean follow up 2.70 months. Safety: 16 non-treatment-related SAEs in 9 patients. 2 treatment-related Grade ≥3 AEs: sepsis (4%) and lymphopenia (4% ). No treatment-related deaths. Efficacy: 23 patients in the mITT population with first CT scan at day 64: ORR: CR: 2, PR: 3 (22%); SD: 6 (26%), PD: 7 (30%), non-evaluable: 5 (22%). Disease control rate (48%). 5 patients on study have not had a CT scan. Conclusions: SD-101 with Pembrolizumab shows early promising data and is well tolerated. Additional follow-up scans from both dose cohorts are being evaluated and will be presented. Clinical trial information: NCT02521870.

Sexual activity and function in male cancer patients receiving targeted an immune therapies

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Background: Survivorship concerns–including sexual function–move increasingly to the foreground in cancer patient care as systemic therapies improve response and survival. Patients are often committed to long-term treatment with tyrosine kinase inhibitors (TKI) and immune checkpoint inhibitors (ICI) despite poor characterization of their effects on sexual function. We sought to assess sexual activity and function in patients receiving TKI or ICI. Methods: A cohort of men receiving TKI/ICI at the UCSF Helen Diller Family Comprehensive Cancer Center were retrospectively identified. Eligible men were on ongoing TKI/ICI therapy. Detailed questionnaires addressing cancer history, treatment history, and sexual activity/function while receiving therapy were completed. Results: Between January 2013 to September 2016, 51 men completed questionnaires. Mean age was 46 years (SD 12, range 21-72). Most (61%) were CML patients, with 12% RCC, 10% GIST, 6% melanoma, and NET, oligodendroglioma, and HCC comprising remaining histologies. 96% were treated with TKI, and 4% with ICI (pembrolizumab). 32% identified as being married or in a domestic partnership, and 18% identified as single. Only 14% reported no attempted sexual activity. Sexual desire was described as low or very low to none in 29%, average in 39%, and high or very high in 29%. Since cancer diagnosis, 21 (41%) of patients noted a reduced amount of semen upon ejaculation, and all but 5 of those patients noted this as at least somewhat bothersome. 35% of patients reported feeling at least somewhat distressed from sexual experiences since cancer diagnosis, including concern that their time to ejaculation may leave their partners feeling unfulfilled (45%), decreased sensation of orgasm (35%), difficulty maintaining erection until completion of intercourse (23%), and pain/discomfort upon ejaculation (12%). Conclusions: The majority of men on TKI or ICI remain sexually active, with a significant portion reporting sexual dysfunction. These findings highlight the need for oncology care providers to proactively manage sexual dysfunction to improve quality of life for cancer patients. Retrospective and prospective studies are ongoing to further characterize this cohort.

Efficacy and safety of nivolumab (NIVO) plus ipilimumab (IPI) in patients with melanoma (MEL) metastatic to the brain: Results of the phase II study CheckMate 204

9507

Background: Brain metastases (BMts) are a major cause of morbidity/death in MEL. We report the first efficacy data in MEL patients (pts) with BMts who received NIVO+IPI in study CheckMate 204. Methods: In this multicenter US trial (NCT02320058), MEL pts with ≥1 measurable BMt 0.5-3.0 cm and no neurologic symptoms or steroid Rx received NIVO 1 mg/kg + IPI 3 mg/kg Q3W x 4, then NIVO 3 mg/kg Q2W until progression or toxicity. Pts with severe adverse events (AEs) during NIVO+IPI could receive NIVO when toxicity resolved; stereotactic radiotherapy (SRT) was allowed for brain oligo-progression if an assessable BMt remained. The primary endpoint was intracranial (IC) clinical benefit rate (complete response [CR] + partial response [PR] + stable disease [SD] > 6 months). The planned 90-pt accrual is complete; we report efficacy and updated safety for 75 pts with disease assessment before the Nov 2016 database lock. Results: Median age was 59 yrs (range 22–79). Median number of induction doses was 3; 26 pts (35%) received 4 NIVO+IPI doses and 38 pts (51%) began NIVO maintenance. Response data are reported at a median follow-up of 6.3 months (Table). The IC objective response rate (ORR) was 56% (95% CI: 44–68); 19% of pts had a complete response. IC and extracranial responses were largely concordant. Rx-related grade 3/4 AEs occurred in 48% of pts, 8% neurologic, including headache and syncope. Only 3 pts (4%) stopped Rx for Rx-related neurologic AEs. One pt died of immune-related myocarditis. Conclusions: In CheckMate 204, prospectively designed to investigate NIVO+IPI in MEL pts with BMts, NIVO+IPI had high IC antitumor activity with objective responses in 56% of pts, CR in 19%, and no unexpected neurologic safety signals. The favorable safety and high anti-melanoma activity of NIVO+IPI may represent a new Rx paradigm for pts with asymptomatic MEL BMts and could change practice to avoid or delay whole brain RT or SRT. Clinical trial information: NCT02320058. [Table: see text]

Analysis of mutational burden and adaptive immune response in desmoplastic melanomas treated with PD-1/L1 inhibitors

9558

Background: Desmoplastic melanoma (DM) is a rare subtype of melanoma characterized by a dense fibrous stroma, resistance to chemotherapy and no actionable driver mutation for targeted therapy. We investigated the efficacy of PD-1/L1 inhibitors and correlation with genetic landscape and tumor immune microenvironment in DM. Methods: Retrospective analysis of 1054 pts with melanoma treated with anti-PD-1/L1, resulting in 57 pts with unresectable or metastatic DM. Available baseline biopsies were analysed by digital quantitative immunohistochemistry (IHC) for CD8 and PD-L1 and by whole exome sequencing (WES), compared to available tissue from non-DM pts treated with anti-PD1/L1 at UCLA. Results: At a median follow up of 20 mo, 40 pts (70%, 95% CI 57-82) had an objective response by RECIST 1.1 criteria, including 18 (45%) CRs with no relapse observed to date. Responses were similar in DM subsets (23 pure, 29 mixed and 5 indeterminate). Kaplan-Meier estimated 1-year and 2-year overall survival were 85% (95% CI 78-98) and 74% (95% CI 64-89). WES revealed a median of 1282 (interquartile range 517-1692) non-synonymous somatic mutations per tumor in DM tumors (n = 17), significantly higher (p = 0.02) than the median of 462 (interquartile range 230-1150) in non-DM (n = 23). Mutations in NF-1 were the most common (13/17) followed by loss-of-function TP53 and ARID2, and > 82% of single nucleotide mutations were UV damage signatures. IHC analysis from 19 DM and 13 non-DM revealed a strikingly higher percentage of PD-L1 positive cells in the tumor parenchyma in DM (p = 0.04), highly associated with CD8 density and PD-L1 expression in the tumor invasive margins, indicating an active adaptive immune response. No genetic mechanisms known to cause constitutive PD-L1 expression were detected in these samples. Conclusions: Patients with advanced DM derive significant clinical benefit from PD-1/L1 inhibitors, likely related to the high mutational burden and a highly active adaptive immune response as the main mechanism of immune escape prior to therapy. Our results challenge the general conception that dense fibrous stroma around the malignant cells interferes with immune cell infiltration and efficacy of immunotherapy.

Patient attitudes toward oncofertility care in male cancer patients receiving targeted and immune therapies

e21593

Background: Tyrosine kinase inhibitors (TKI) and immune checkpoint inhibitors (ICI) have resulted in durable response for many cancer patients. The impact of these agents on future fertility are not well described, and patients are often committed to long-term treatment without adequate oncofertility counseling. We sought to better characterize patient attitudes toward oncofertility and challenges faced by male cancer patients undergoing treatment with TKI or ICI. Methods: Men receiving TKI/ICI at the UCSF Helen Diller Family Comprehensive Cancer Center were retrospectively identified. Eligible men had received at least one dose of TKI/ICI. Detailed questionnaires addressing cancer history, possible effects of treatment on fertility, and obstacles to fertility preservation were completed. Results: Between January 2013 to September 2016, 51 men with a mean age of 46 years (SD 12, range 21-72), 65% white, completed questionnaires. Most (61%) were CML patients, with 12% RCC, 10% GIST, 6% melanoma, and NET, oligodendroglioma, and HCC comprising remaining histologies. 96% were treated with TKI, and 4% with ICI. At the time of diagnosis, 35% of patients indicated a desire to father future children, and 53% believed that cancer treatment might affect their fertility. Despite this, 45% were not asked whether having children was important to them, and 47% did not receive information from any provider on their oncology care team about the possible risks of TKI/ICI to future fertility. The majority of patients felt there was inadequate discussion of how treatment might affect testosterone levels (73%) and their ability to father a child (53%), yet only 14% recalled adequate referrals to a fertility specialist. Conclusions: These data demonstrate that male cancer patients perceive treatment-related infertility risks as important, yet have few opportunities to discuss these concerns with providers. Care plans to address oncofertility needs, especially as TKI/ICI are increasingly used in multiple cancer types, are needed as part of the diagnosis, treatment, and follow up of these patients. Larger retrospective and prospective studies are ongoing to further characterize this patient cohort.

SWOG S1221: A phase 1 dose escalation study co-targeting MAPK-dependent and MAPK-independent BRAF inhibitor resistance in BRAF mutant advanced solid tumors with dabrafenib, trametinib, and GSK2141795 (ClinicalTrials.gov NCT01902173)

2578

Background: Aberrant PI3K/AKT signaling in BRAF mutant cancers contributes to resistance to MAPK pathway blockade. We conducted parallel phase 1 dose escalation studies of the doublet of the BRAFi dabrafenib with the AKT inhibitor GSK2141795 and of the triplet of dabrafenib, the MEKi trametinib, and GSK2141795. Methods: Patients (pts) with BRAF-V600E/K mutant advanced solid tumors with adequate end-organ function were eligible regardless of prior BRAFi and MEKi exposure. All pts received dabrafenib at 150 mg twice daily (bid), in the doublet cohorts together with dose escalation (3 + 3 scheme) of GSK2141795 started at 50 mg daily (qd), and in the triplet cohorts with dose escalation of both trametinib starting at 1.5 mg qd and GSK2141795 starting at 25 mg qd. DLTs included significant grade 3 and 4 adverse events (CTCAE v4) within the first 56 days of treatment. Radiographic responses were assessed at 8-week intervals. Results: No DLTs were observed in the doublet cohorts (N = 8) up to dabrafenib 150 mg bid and GSK2141795 75 mg qd. In the triplet cohorts (N = 11), no DLTs were observed at doses of up to trametinib 1.5 mg daily with GSK2141795 75 mg daily. At the highest triplet dose with dabrafenib 150 mg bid, trametinib 2 mg qd with GSK2141795 75 mg qd, 1 of 2 evaluable pts had a DLT of grade 3 febrile neutropenia and grade 3 maculo-papular rash. 2/2 treatment-naïve in the doublet cohorts had PRs (1 melanoma and 1 thyroid) the latter lasting over 1 year. 1/6 BRAF inhibitor-refractory (melanoma) pts also had an objective response. In the triplet cohorts, 3 of 6 treatment-naïve pts had a PR (1 melanoma, 2 lung). One lung pt remains in PR at 2 months and the otherhas an uPR at 1.2 months. Conclusions: Inhibition of both MAPK and PI3K/AKT pathways was well tolerated, leading to durable objective responses in pts with metastatic melanoma, thyroid cancer, and lung cancer. Further study of dual pathway inhibition is warranted. Funding: Supported in part by NIH/NCI grants CA180888, CA180819; and in part by Novartis Pharmaceuticals Corporation and GlaxoSmithKline, LLC. Clinical trial information: NCT01902173.

Relationship between liver metastases and PD-1 blockade in melanoma

3072

Background: WhilePD-1 blockade is effective in melanoma, durable responses remain elusive. We have previously reported that liver metastasis is associated with reduced response rates and that the fraction of CTLA4 hi/PD-1 hi CD8+ cells (“activated-exhausted” or T-ex cells) within the TIL is predictive of response to PD-1 blockade. Here, we explore the biology behind liver metastasis in human melanoma and in animal models. Methods: Patients with metastatic melanoma with or without liver metastasis were biopsied pre- PD-1 treatment and immune infiltrates were analyzed by FACS. The CD8 fraction was gated on CTLA4 and PD-1. C57BL/6 mice were implanted with a “primary” subcutaneous tumor and a “metastatic” tumor in the liver or the lungs (control), and given systemic PD-1 blockade therapy. Results: Patients with melanoma and liver metastasis (n = 25) had 15.2% T-ex cells while those without liver metastasis (n = 76) had 26.5 % T-ex cells, p = 0.0092. A T-ex fraction < 20% was significantly associated with lack of PD-1 response, p < 0.005. In C57BL/6 mice implanted with a B16 tumor (subQ & liver) treated with PD-1 antibody, 0/35 mice achieved subQ tumor rejection while in the SubQ only mice 9/30 mice (30%) rejected their tumors. The mean tumor size of mice with Sub Q+liver metastasis was 139.2 mm2 vs subQ only mice 23.4 mm2 at d 14, p = 0.002. Mice with liver metastasis showed a T-ex fraction 31.9% vs 67.3%without liver met, p = 0.0003. In contrast, in mice made lung metastatic, the subQ tumor rejection rate was 7/20 (35%), with T-ex infiltrate at 57.9%. The implantation of liver metastases from an unrelated MC38 tumor does not protect the subQ tumor from immune rejection. Conclusions: The presence of liver metastases is associated with reduced response to PD-1 blockade and reduced T-ex infiltrate in patients with stage IV melanoma. Mechanistic studies using a mouse model of syngeneic organ site specific metastasis confirms that the liver metastasis results in reduced antigen specific T cell at distant sites, resulting in reduced response. Site of metastasis may determine immune responsiveness in both mouse models and in humans with melanoma.

Immune monitoring outcomes of patients with stage III/IV melanoma treated with a combination of pembrolizumab and intratumoral plasmid interleukin 12 (pIL-12)

78

Background: Recent publications support the emergence of predictive biomarkers for pembrolizomab in melanoma based on the expression of PD-L1 in the tumor microenvironment (Daud 2016a) or the frequency of PD-1hiCTLA-4hi on CD8+ TIL (Daud 2016b) whereby immunologically inactive tumors show poor response to immune checkpoint inhibition alone. Since intratumoral pIL-12 with electroporation (IT-pIL12-EP) increases TIL in both treated and untreated lesions, we hypothesize that non-response can be rescued with the combination of IT-pIL12-EP and anti-PD-1. Phase II clinical and immunological data are shown. Methods: Melanoma stage III/IV patients were enrolled with CD8+ TIL < 25% PD-1hiCTLA-4+measured by flow cytometry (NCT02493361). PD-L1 IHC (22C3 Ab) was also evaluated. Patients were treated with pembrolizumab (200mg every 3 weeks) and IT-pIL12-EP. Patients were evaluated for ORR every 12 weeks (RECISTv1.1). Pre- and post-treatment blood and tumor specimens were collected, and analyzed for immune phenotyping, gene expression, T cell receptor diversity, and changes in the tumor microenvironment by IHC. Results: TIL assessment for evaluable enrolled patients were < 22% PD-1hiCTLA-4+, a value associated with anti-PD-1 non-response (Daud 2016b). Remarkably, although predicted to be an unresponsive population, the ORR was 40% (4CR/ 2PR) by RECISTv1.1. In patients with CR/PR, analysis of the tumor microenvironment revealed many significant immunological changes not seen in non-responders, including number and ratios of CD8+:PD-L1+by IHC, increased expression of NK, CD8 and ‘adaptive resistance’ markers by NanoString, as well as increased clonality and T cells by TCR sequencing. Conclusions: The excellent safety profile and striking 40% clinical response rate is encouraging as treated patients were predicted to be non-responsive to pembrolizumab. The correlative data shows an immune-directed mechanism that is differentiated between responders and non-responders suggesting the combination can effectively alter the tumor microenviroment to benefit patients otherwise unlikely to respond to anti-PD-1 monotherapy. Clinical trial information: NCT02493361.

The combination of axitinib followed by paclitaxel/carboplatin yields extended survival in advanced BRAF wild-type melanoma: results of a clinical/correlative prospective phase II clinical trial

BACKGROUND

Simultaneous chemotherapy with vascular endothelial growth factor (VEGF) inhibition has not shown additional benefit over chemotherapy alone in advanced melanoma. We tested administration of the potent VEGF inhibitor axitinib followed by paclitaxel/carboplatin to determine whether enhanced tumour proliferation during axitinib withdrawal leads to sustained chemosensitivity.

METHODS

We conducted a prospective phase II trial in metastatic melanoma patients with ECOG performance status 0-1 and normal organ function. Axitinib 5 mg PO b.i.d. was taken on days 1-14 of each 21-day treatment cycle, and carboplatin (AUC=5) with paclitaxel (175 mg m(-2)) was administered on day 1 starting with cycle 2. 3'-Deoxy-3'-(18)F-fluorothymidine ((18)F-FLT)-PET scans were performed in five patients to assess tumour proliferation on days 1, 14, 17, and 20 of cycle 1. Molecular profiling for BRAF was performed for all patients with cutaneous, acral, or mucosal melanoma.

RESULTS

The treatment was well tolerated. The most common grade 3 AEs were hypertension, neutropenia, and anaemia. Grade 4 non-haematologic AEs were not observed. Four of five patients completing (18)F-FLT-PET scans showed increases (23-92%) in SUV values during the axitinib holiday. Of 36 evaluable patients, there were 8 confirmed PRs by Response Evaluation Criteria in Solid Tumors. Overall, 20 patients had SD and 8 had PD as the best response. The median PFS was 8.7 months and the median overall survival was 14.0 months. Five BRAF(V600E/K) patients had significantly worse PFS than patients without these mutations.

CONCLUSIONS

Axitinib followed by carboplatin and paclitaxel was well tolerated and effective in BRAF wild-type metastatic melanoma. 3'-Deoxy-3'-(18)F-fluorothymidine-PET scans showed increased proliferation during axitinib withdrawal.

BKM120 combined with vemurafenib in vemurafenib-refractory BRAF mutant metastatic melanoma: Two cases

e20010

Background: PTEN loss and PI3K activation are common in BRAF mutant metastatic melanoma, and PI3K activation has been implicated as a cause of acquired resistance to BRAF inhibitors. Two vemurafenib refractory were treated with the potent BRAF inhibitor, vemurafenib, and the pan-class I PI3K inhibitor BKM120. Methods: The study enrolled BRAF-V600E/K mutant metastatic melanoma patients with an ECOG PS ≥ 2 and adequate organ function. Vemurafenib refractory BRAF-V600E/K mutant melanoma patients started both vemurafenib twice daily and BKM120 daily on cycle 1, day 1 after a vemurafenib washout of at least 14 days. Serial biopsies prior to treatment, on cycle 1 day 15, and at progression were obtained for pharmacodynamics analysis in patients with visible or palpable tumors. Results: 3 BRAF inhibitor refractory patients were treated on study with vemurafenib 720 mg PO bid and BKM120 60 mg PO daily. One patient was inevaluable due to non-compliance and had minimal exposure to study drug. Pre-treatment biopsy specimens were available in the remaining 2 vemurafenib-refractory patients. Both patient expressed PTEN at baseline and had demonstrable pAKT and pS6 staining. One patient had a mixed response to treatment with a 35.9% reduction in target lesions and two new small subcutaneous lesions. This patient also developed dose limiting febrile neutropenia on trial. The second patient tolerated treatment well but had widespread disease progression at 8 weeks. Conclusions: Combination therapy with vemurafenib and BKM120 in BRAF-V600E/K mutant melanoma led to substantial regression of several tumors in a PTEN+ patient with prior disease progression on vemurafenib alone. A phase I dose escalation trial in ongoing. Clinical trial information: NCT01512251.

First-in-human dose escalation study of LY2875358 (LY), a bivalent MET antibody, as monotherapy and in combination with erlotinib (E) in patients with advanced cancer

8093

Background: Activation of the hepatocyte growth factor (HGF)/MET receptor pathway promotes tumor growth, invasion and dissemination. LY is a humanized IgG4 monoclonal bivalent antibody against MET which inhibits ligand dependent- and ligand independent activation of MET. Based on preclinical results, we examined LY alone in patients with advanced solid tumors and LY+E in advanced NSCLC patients. Methods: LY monotherapy was administered 20-2,000 mg Q2W IV to 23 patients with advanced solid tumors. Combination therapy with 700-2,000 mg Q2W IV of LY and E (150 mg QD) was completed in 14 patients with advanced NSCLC. The primary objective was to determine a recommended phase II dose (RPTD) for LY and LY+E. Secondary objectives included assessment of toxicity, PK, PD (including MET extracelluar domain and HGF), and antitumor activity. Results: LY and LY+E were well tolerated. No dose-limiting toxicities, serious adverse events, or ≥ Grade 3 adverse events (AEs) possibly related to LY have been observed. The most frequent (≥5% of patients) AEs possibly related to LY2875358 monotherapy were nausea (8.7 %), vomiting (8.7%), and diarrhea (8.7%). The most frequent (≥10% of patient) grade 1 or 2 adverse event possibly related to LY2875358 in patients treated with LY+E were fatigue (21.4%) and anorexia (14.3%). Durable PR according to RECIST were observed for LY (n=1) and LY+E (n=2 out of 13 evaluable patients; both PR patients positive for MET protein expression). Conclusions: LY appears to be safe when administered as single agent and in combination with E up to 2,000 mg Q2W IV. The RPTD of LY is 750 mg Q2W IV for monotherapy and in combination with E based on PK/PD data. Clinical trial information: NTC 01287546.

BRAF inhibitor (BRAFi) dabrafenib in combination with the MEK1/2 inhibitor (MEKi) trametinib in BRAFi-naive and BRAFi-resistant patients (pts) with BRAF mutation-positive metastatic melanoma (MM)

9005

Background: Dual inhibition of the MAP kinase (MAPK) pathway with dabrafenib (D) and trametinib (T) in combination has demonstrated clinical benefit compared to D alone in a randomized Phase II trial in V600 BRAF-mutant MM pts, thus delaying the development of BRAFi resistance. Little is known about the efficacy of D + T after BRAFi resistance has been acquired. This analysis evaluates the ability of D + T combination to treat acquired resistance compared to the D + T combination as first-line treatment. Methods: These data from a phase I/II study include 1. BRAFi-resistant group: pts who received 150/2 D+T in Part B (n=26) and Part C (n=43) following progression on BRAFi monotherapy (mono); 2. BRAFi-naïve group: pts who received initial 150/2 D+T in Part B (n=24) and Part C (n=54). Results: Baseline characteristics (ECOG PS, M staging, LDH) were similar across all groups.In the Part B BRAFi-resistant group, 93% of pts previously received D or vemurafenib and all pts received D prior to D+T in Part C. In BRAFi-resistant group, prior best response of CR/PR (38%, 56%), SD (35%, 27%), PD (27%, 7%) was observed in Parts B and C respectively. In BRAFi-resistant group, the ORR and PFS with D+T was lower than initial D+T in BRAFi-naive group. Median duration of response (DoR) in BRAFi-resistant group cannot be calculated due to small no. of pts responding. Median DoR for BRAFi-naïve pts was 11.3 mo and 10.5 mo in Parts B and C respectively. In Part C, the 12-mo overall survival rates in BRAFi-naïve (150/2) pts was 79% vs 70% for pts initially on D mono, despite 80% pts crossing over to D+T combination. Conclusions: The clinical activity for 150/2 D+T combination is consistently superior in BRAFi-naive group vs BRAFi-resistant group in both Parts B and C. Dual MAPK blockade can delay clinical resistance to BRAF inhibition. However, once BRAFi resistance has occurred, the combination of BRAFi + MEKi is far less effective. Clinical trial information: NCT01072175. [Table: see text]

Updated safety and efficacy results from a phase I/II study of the oral BRAF inhibitor dabrafenib (GSK2118436) combined with the oral MEK 1/2 inhibitor trametinib (GSK1120212) in patients with BRAFi-naive metastatic melanoma

8510

Background: In preclinical models, the BRAFi/MEKi combination has demonstrated enhanced activity against BRAF-mutant cancer cells compared with either drug alone, delayed emergence of BRAFi resistance, and prevented BRAFi-related proliferative skin lesions. A 3-part study investigating the dabrafenib/trametinib combination was conducted in patients (pts) with V600 BRAF mutant solid tumors. Interim data from the study were previously reported (Infante, ASCO 2011); updated safety and efficacy data are presented. Methods: In Part 2, 125 pts with V600 BRAF mutant solid tumors enrolled, including 77 melanoma pts with no prior BRAFi, and measurable disease according to RECIST 1.1. Pts were treated on 4 escalating dose levels of dabrafenib/trametinib (mg BID/mg QD): 75/1, 150/1, 150/1.5, 150/2. Demographic and efficacy data for the 77 melanoma pts with no prior BRAFi and safety data for all 125 Part 2 pts are reported. Results: Among 77 melanoma pts, median age was 52 years, 61% male, 57% ECOG PS of 0, 91% V600E, 65% M1c stage, 26% prior brain metastases, and 52% LDH > ULN. Confirmed ORR was 56% (95% CI: 44.1%-67.2%) with 4 CR, 39 PR, 29 SD and, 3 PD. Confirmed response rate for each dose level, respectively, was 67% (n=6), 64% (n=22), 48% (n=25), and 54% (n=24). Median PFS (months) for each dose level, respectively, was: 8.7, 8.3, 5.5; PFS is not mature for 150/2. Overall PFS was 7.4 (95% CI: 5.5-9.2). Among the 125 pts, there were 2 grade (G) 5 adverse events (AEs), pneumonia and hyponatraemia. The most common G3/4 AEs were pyrexia (n=6, 5%), fatigue (n=6, 5%) and dehydration (n=6, 5%). Skin toxicity ≥ G2 occurred in 17 (14%) pts. Cutaneous squamous cell carcinoma occurred in 3 (2%) pts and actinic keratoses in 2 (2%). Conclusions: The combination of dabrafenib/trametinib has an acceptable safety profile, with a lower incidence of MEKi-related rash and BRAFi-induced hyperproliferative skin lesions compared with the single agents. The clinical activity of dabrafenib/trametinib observed in pts with V600 BRAF mutant metastatic melanoma is encouraging and will be investigated further in a phase III trial.

A phase I/II trial of BKM120 combined with vemurafenib (PLX4032) in BRAFV600E/k mutant advanced melanoma

TPS8602

Background: Vemurafenib induces transient objective responses in half of BRAFV600E mutant melanoma patients and a median PFS of 5.3 months (NEJM. 2011;364:2507-2516). BRAF mutations are not sufficient to cause melanoma, but the combination of BRAFV600E mutation and PTEN loss is sufficient to recapitulate the malignant melanoma phenotype in vivo (Nat. Genet. 2009;41:544-552). PTEN loss and PI3K activation are common in BRAF mutant metastatic melanoma, and PI3K activation has been implicated as a cause acquired resistance to BRAF inhibitors (Cancer Cell. 2010;18:683-695). This phase I/II study is the first trial to test the safety and efficacy of combining a potent BRAF inhibitor, vemurafenib, with a potent PI3K inhibitor, BKM120, in patients with metastatic BRAF mutant melanoma. Methods: Design: Phase I patients receive a single dose of oral BKM120 (d -7) then vemurafenib twice daily with BKM120 daily (starting on c1d1). PK analysis is performed for BKM120 alone and for both drugs in combination. Doses of both drugs will be escalated in 3+3 scheme. Phase II patients receive continuous dosing of vemurafenib twice daily and BKM120 daily. Serial biopsies for PD and mRNA expression analyses are required for patients with visible or palpable tumors. Reimaging will be performed every 8 weeks.Eligibility: This study is enrolling BRAFV600E/K mutant metastatic melanoma patients with no prior exposure to BRAF inhibitors or PI3K inhibitors, ECOG PS ≥ 2 and adequate organ function. Endpoints: The primary endpoint for phase 1 is the recommended phase 2 dose of the combination. The primary endpoint for phase II is the 6 month PFS rate. Secondary endpoints include median PFS and OS. Baseline PTEN expression and changes is pS6 protein levels will be examined as predictors of efficacy, and changes in gene expression profiles will be assessed. Summary: This is the first trial examining the safety and efficacy of combined BRAF/PI3K inhibition in BRAF mutant melanoma patients.

Association of pyrexia and durable response in advanced melanoma patients treated with the combination of dabrafenib and trametinib

e19046

Background: Pyrexia (fever) is a common adverse event associated with combined BRAF and MEK inhibition (dabrafenib and trametinib). Although the mechanism of fever is unclear, we explore pyrexia as a pharmacodynamic marker for clinical response. Methods: A phase II international trial with dabrafenib and trametinib in metastatic melanoma (MM) and colorectal cancers (CRC) harboring BRAF mutations is ongoing. Twenty-nine patients (pts) were enrolled at UCSF between January 2011 and January 2012. Fevers were graded based on temperature and coinciding symptoms, and an episode of pyrexia was defined as a temperature of >100 °F at least once a day for one or more consecutive days. Tumor assessments were performed every 8 weeks (wks). Results: To date, 13 pts with MM and 5 with CRC had tumor assessments up to 24 wks. In MM, pyrexia was reported 2 or more times in 7 pts; 5 had none, and 1 reported one episode of Grade 1 pyrexia. Episodes occurred 2-4 wks after starting treatment, and time between subsequent recurrences ranged from 1 to 25 wks. Neutrophil counts showed early fluctuations, but none had neutropenia. Of the 7 pts with recurring fevers, 5 had partial responses and 2 had stable disease at 8 wks. Of the 6 pts with nonrecurring or no fevers, 2 had partial responses at 8 wks, and 1 progressed. At 24 wks, all 7 pts with ≥ 2 fever episodes remained progression-free, whereas 0/6 pts with < 2 fever episodes were progression-free (p < 0.001). Pts without progression continued to have recurring fevers (median = 4). There were no differences by disease stage (12 of 13 with M1c) or mutation status (10 with V600E; 2 with V600K; 1 with V600E + V601I). While pts with CRC had pyrexia, no association between pyrexia and response was noted; however, only 5 pts are included in this analysis. Conclusions: In this limited analysis of pts with MM, recurrent fevers were associated with durable response (≥ 24 wks). These results suggest that pyrexia could be a marker for inflammation and antitumor activity. Further studies are underway to characterize cytokine profiles and immune responses. [Table: see text]

A clinical and translational phase II trial of sequential axitinib and carboplatin/paclitaxel in advanced melanoma

8580

Background: Several clinical trials adding VEGF signaling inhibitors to chemotherapy have not demonstrated any benefit over chemotherapy alone in advanced melanoma potentially due to decreased tumor cell proliferation induced by VEGF blockade. We tested the hypothesis that sequential administration of axitinib followed by carboplatin and paclitaxel may be more effective than chemotherapy alone in metastatic melanoma. Methods: We conducted a prospective phase II trial of this combination in previously treated metastatic melanoma patients. Patients had an ECOG PS 0-1, and normal organ function. Axitinib 5 mg PO bid was taken on days 1 through 14 of each 21-day treatment cycle, and carboplatin (AUC=5) with paclitaxel (175 mg/m2) was administered on day 1 starting with cycle 2. FLT-PET scans were performed on 6 patients to assess tumor cell proliferation on days 1, 14, 17, and 20 of cycle 1. Results: Treatment has been well tolerated. The most common grade 3 AEs have been neutropenia, hypertension, and gastrointestinal events. Grade 4 non-hematologic AEs have not been observed. 4 of 5 patients completing FLT-PET scans to date showed increases (23% to 92%) in SUV values during the axitinib holiday. The fifth patient had a single, minimally FLT avid lesion at baseline (SUV=1.9). In 30 evaluable patients, there have been 4 confirmed PRs, 2 unconfirmed PRs, and 3 patients with 28.6, 29.3, and 29.5% decreases in tumor size by RECIST. Overall, 19 patients have had SD and 5 have had PD as the best response. With a median follow-up of 8.3 months and 17 patients still active, the median PFS is 6.9 months, and 23 patients (77%) are still alive. 26 of 30 evaluable patients have been wild type for BRAF-V600E/K mutations. Conclusions: Axitinib followed by carboplatin and paclitaxel has been well tolerated and effective in a largely BRAF wild-type metastatic melanoma population. Given the urgent need for effective therapies in this population, this regimen warrants phase III testing.

Phase I clinical trial of the Src inhibitor dasatinib with dacarbazine in metastatic melanoma

Background:

Src inhibitors sensitise melanoma cells to chemotherapy in preclinical models. The combination of dasatinib and dacarbazine was tested in a phase I trial in melanoma.

Methods:

Patients had ECOG performance status 0–2 and normal organ function. Dacarbazine was administered on day 1 and dasatinib on day 2 through 19 of each 21-day cycle. Both were escalated from 50 mg b.i.d. of dasatinib and 800 mg m⁻² of dacarbazine. Available pre-treatment biopsies were sequenced for BRAF, NRAS, and C-Kit mutations.

Results:

Dose-limiting toxicity was reached at dasatinib 70 mg b.i.d./dacarbazine 1000 mg m⁻², and was predominantly haematological. In 29 patients receiving dasatinib 70 mg b.i.d., the objective response rate (ORR) was 13.8%, the clinical benefit rate (ORR+SD) was 72.4%, the 6-month progression-free survival (PFS) was 20.7%, and the 12-month overall survival (OS) was 34.5%. Two out of three patients who were wild type for BRAF, NRAS, and c-KIT mutations had confirmed partial responses, and one had a minor response.

Conclusion:

The recommended phase II dose is dasatinib70 mg b.i.d with dacarbazine 800 mg m⁻². PFS and OS data for dasatinib at 70 mg b.i.d. with dacarbazine compared favourably with historical controls. Preliminary data support evaluating tumour mutation status further as a biomarker of response.

Phase II trial of sagopilone, a novel epothilone analog in metastatic melanoma

BACKGROUND

Sagopilone is a novel fully synthetic epothilone with promising preclinical activity and a favourable toxicity profile in phase I testing.

METHODS

A phase II pharmacokinetic and efficacy trial was conducted in patients with metastatic melanoma. Patients had measurable disease, Eastern Cooperative Oncology Group performance status 0-2, adequate haematological, and organ function, with up to 2 previous chemotherapy and any previous immunotherapy regimens. Sagopilone, 16 mg m⁻², was administered intravenously over 3 h every 21 days until progression or unacceptable toxicity.

RESULTS

Thirty-five patients were treated. Sagopilone showed multi-exponential kinetics with a mean terminal half-life of 64 h and a volume of distribution of 4361 l m⁻² indicating extensive tissue/tubulin binding. Only grade 2 or lower toxicity was observed: these included sensory neuropathy (66%), leukopenia (46%), fatigue (34%), and neutropenia (31%). The objective response rate was 11.4% (one confirmed complete response, two confirmed partial responses, and one unconfirmed partial response). Stable disease for at least 12 weeks was seen in an additional eight patients (clinical benefit rate 36.4%).

CONCLUSION

Sagopilone was well tolerated with mild haematological toxicity and sensory neuropathy. Unlike other epothilones, it shows activity against melanoma even in pretreated patients. Further clinical testing is warranted.