Oncology clinical trial disruption during the COVID-19 pandemic: a COVID-19 and cancer outcomes study

Background

COVID-19 disproportionately impacted patients with cancer as a result of direct infection, and delays in diagnosis and therapy. Oncological clinical trials are resource-intensive endeavors that could be particularly susceptible to disruption by the pandemic, but few studies have evaluated the impact of the pandemic on clinical trial conduct.

Patients and methods

This prospective, multicenter study assesses the impact of the pandemic on therapeutic clinical trials at two large academic centers in the Northeastern United States between December 2019 and June 2021. The primary objective was to assess the enrollment on, accrual to, and activation of oncology therapeutic clinical trials during the pandemic using an institution-wide cohort of (i) new patient accruals to oncological trials, (ii) a manually curated cohort of patients with cancer, and (ii) a dataset of new trial activations.

Results

The institution-wide cohort included 4756 new patients enrolled to clinical trials from December 2019 to June 2021. A major decrease in the numbers of new patient accruals (−46%) was seen early in the pandemic, followed by a progressive recovery and return to higher-than-normal levels (+2.6%). A similar pattern (from −23.6% to +30.4%) was observed among 467 newly activated trials from June 2019 to June 2021. A more pronounced decline in new accruals was seen among academically sponsored trials (versus industry sponsored trials) (P < 0.05). In the manually curated cohort, which included 2361 patients with cancer, non-white patients tended to be more likely taken off trial in the early pandemic period (adjusted odds ratio: 2.60; 95% confidence interval 1.00-6.63), and substantial pandemic-related deviations were recorded.

Conclusions

Substantial disruptions in clinical trial activities were observed early during the pandemic, with a gradual recovery during ensuing time periods, both from an enrollment and an activation standpoint. The observed decline was more prominent among academically sponsored trials, and racial disparities were seen among people taken off trial.

Association of clinical factors and recent anticancer therapy with COVID-19 severity among patients with cancer: a report from the COVID-19 and Cancer Consortium

BACKGROUND

Patients with cancer may be at high risk of adverse outcomes from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We analyzed a cohort of patients with cancer and coronavirus 2019 (COVID-19) reported to the COVID-19 and Cancer Consortium (CCC19) to identify prognostic clinical factors, including laboratory measurements and anticancer therapies.

PATIENTS AND METHODS

Patients with active or historical cancer and a laboratory-confirmed SARS-CoV-2 diagnosis recorded between 17 March and 18 November 2020 were included. The primary outcome was COVID-19 severity measured on an ordinal scale (uncomplicated, hospitalized, admitted to intensive care unit, mechanically ventilated, died within 30 days). Multivariable regression models included demographics, cancer status, anticancer therapy and timing, COVID-19-directed therapies, and laboratory measurements (among hospitalized patients).

RESULTS

A total of 4966 patients were included (median age 66 years, 51% female, 50% non-Hispanic white); 2872 (58%) were hospitalized and 695 (14%) died; 61% had cancer that was present, diagnosed, or treated within the year prior to COVID-19 diagnosis. Older age, male sex, obesity, cardiovascular and pulmonary comorbidities, renal disease, diabetes mellitus, non-Hispanic black race, Hispanic ethnicity, worse Eastern Cooperative Oncology Group performance status, recent cytotoxic chemotherapy, and hematologic malignancy were associated with higher COVID-19 severity. Among hospitalized patients, low or high absolute lymphocyte count; high absolute neutrophil count; low platelet count; abnormal creatinine; troponin; lactate dehydrogenase; and C-reactive protein were associated with higher COVID-19 severity. Patients diagnosed early in the COVID-19 pandemic (January-April 2020) had worse outcomes than those diagnosed later. Specific anticancer therapies (e.g. R-CHOP, platinum combined with etoposide, and DNA methyltransferase inhibitors) were associated with high 30-day all-cause mortality.

CONCLUSIONS

Clinical factors (e.g. older age, hematological malignancy, recent chemotherapy) and laboratory measurements were associated with poor outcomes among patients with cancer and COVID-19. Although further studies are needed, caution may be required in utilizing particular anticancer therapies.

CLINICAL TRIAL IDENTIFIER

NCT04354701.

Impact of contemporary patterns of chemotherapy utilization on survival in patients with advanced cancer of the urinary tract: a Retrospective International Study of Invasive/Advanced Cancer of the Urothelium (RISC)

Background

Cisplatin-based combination chemotherapy is the standard treatment of advanced urinary tract cancer (aUTC), but 50% of patients are ineligible for cisplatin according to recently published criteria. We used a multinational database to study patterns of chemotherapy utilization in patients with aUTC and determine their impact on survival.

Patients and methods

This was a retrospective study of patients with: UTC (bladder, renal pelvis, ureter or urethra); advanced disease (stages T4b and/or N+ and/or M+); urothelial, squamous or adenocarcinoma histology. Primary objective was overall survival (OS). Eligibility-for-cisplatin was defined by Eastern Cooperative Oncology Group performance status ≤ 1, creatinine clearance ≥ 60 ml/min, no hearing loss, no neuropathy and no heart failure. Cox regression multivariate analyses were used to establish independent associations of cisplatin versus noncisplatin-based chemotherapy on OS.

Results

1794 patients treated between 2000 and 2013 at 29 centers were analyzed. Median follow-up was 29.1 months. About 1333 patients (74%) received first-line chemotherapy: the use of first-line chemotherapy was associated with longer OS: [hazard ratio (HR): 1.91, 95% confidence interval (CI): 1.67-2.20]. Type of first-line chemotherapy received was: cisplatin-based 669 (50%), carboplatin-based 399 (30%) and other 265 (20%). Cisplatin use was an independent favorable prognostic factor (HR: 1.54, 95% CI: 1.35-1.77). This benefit was independent of baseline characteristics or comorbidities but was associated with eligibility-for-cisplatin: eligible patients treated with cisplatin lived longer than those who were not (HR: 1.74, 95% CI: 1.36-2.21), while such benefit was not observed among ineligible patients. About 26% of patients who did not receive cisplatin were eligible for this agent. Median OS of ineligible patients was poor irrespective of the chemotherapy used.

Conclusions

The importance of applying published criteria of eligibility-for-cisplatin was confirmed in a multinational, real-world setting in aUTC. The reasons for deviations from these criteria set targets to improve adherence. Effective therapies for cisplatin-ineligible patients are needed.

Second-line single-agent versus doublet chemotherapy as salvage therapy for metastatic urothelial cancer: a systematic review and meta-analysis

BACKGROUND

The efficacy and safety of a combination of chemotherapeutic agent compared with single-agent chemotherapy in the second-line setting of advanced urothelial carcinoma (UC) are unclear. We aimed to study the survival impact of single-agent compared with doublet chemotherapy as second-line chemotherapy of advanced UC.

PATIENTS AND METHODS

Literature was searched for studies including single-agent or doublet chemotherapy in the second-line setting after platinum-based chemotherapy. Random-effects models were used to pool trial-level data according to treatment arm, including median progression-free survival (PFS), overall survival (OS), objective response rate (ORR) probability, and grade 3-4 toxicity. Univariable and multivariable analyses, including sensitivity analyses, were carried out, adjusting for the percent of patients with ECOG performance status ≥1 and hepatic metastases.

RESULTS

Forty-six arms of trials including 1910 patients were selected: 22 arms with single agent (n = 1202) and 24 arms with doublets (n = 708). The pooled ORR with single agents was 14.2% [95% confidence interval (CI) 11.1-17.9] versus 31.9% [95% CI 27.3-36.9] with doublet chemotherapy. Pooled median PFS was 2.69 and 4.05 months, respectively. The pooled median OS was 6.98 and 8.50 months, respectively. Multivariably, the odds ratio for ORR and the pooled median difference of PFS were statistically significant (P < 0.001 and P = 0.002) whereas the median difference in OS was not (P = 0.284). When including single-agent vinflunine or taxanes only, differences were significant only for ORR (P < 0.001) favoring doublet chemotherapy. No statistically significant differences in grade 3-4 toxicity were seen between the two groups.

CONCLUSIONS

Despite significant improvements in ORR and PFS, doublet regimens did not extend OS compared with single agents for the second-line chemotherapy of UC. Prospective trials are necessary to elucidate the role of combination chemotherapy, with or without targeted agents, in the salvage setting. Currently, improvements in this field should be pursued considering single-agent chemotherapy as the foundation for new more active combinations.

Muscle invasive bladder cancer: closing the gap between practice and evidence

Bladder cancer is the fourth most common cancer in the United States, and will lead to an estimated 15,580 deaths in 2014. Prompted by physical symptoms and signs, most patients will initially present with clinically localized disease. Once bladder cancer invades beyond the muscularis propria, the likelihood of development of metastatic disease increases substantially. Radical cystectomy is potentially curative for muscle-invasive bladder cancer though approximately 50% of patients will develop metastatic recurrence. Two large randomized studies have demonstrated that the use of neoadjuvant cisplatin-based chemotherapy prior to cystectomy improves survival. However, despite the existing level 1 evidence, this approach has been largely underutilized in practice. In this review, we will focus on this disconnect between efficacy and effectiveness and explore possible solutions in an effort to bridge this existing gap.

Activity of enzalutamide in men with metastatic castration-resistant prostate cancer is affected by prior treatment with abiraterone and/or docetaxel

BACKGROUND

Enzalutamide and abiraterone are new androgen-axis disrupting treatments for metastatic castration resistant prostate cancer (mCRPC). We examined response and outcomes of enzalutamide-treated mCRPC patients in the real-world context of prior treatments of abiraterone and/or docetaxel.

METHODS

We conducted a seven-institution retrospective study of mCRPC patients treated with enzalutamide between January 2009 and February 2014. We compared baseline characteristics, PSA declines, PSA progression-free survival (PSA-PFS), duration on enzalutamide, and overall survival (OS) across subgroups defined by prior abiraterone and/or docetaxel.

RESULTS

Of 310 patients who received enzalutamide, 36 (12%) received neither prior abiraterone nor prior docetaxel, 79 (25%) received prior abiraterone, 30 (10%) received prior docetaxel, and 165 (53%) received both prior abiraterone and prior docetaxel. Within these groups, respectively, ≥30% PSA decline was achieved among 67%, 28%, 43%, and 24% of patients; PSA-PFS was 5.5 (95% CI 4.2–9.1), 4.0 (3.2–4.8), 4.1 (2.9–5.4), and 2.8 (2.5–3.2) months; median duration of enzalutamide was 9.1 (7.3-not reached), 4.7 (3.7–7.7), 5.4 (3.8–8.4), and 3.9 (3.0–4.6) months. Median OS was reached only for patients who received both prior abiraterone and docetaxel and was 12.2 months (95% CI 10.7–16.5). 12-month OS was 78% (59%–100%), 64% (45%–90%), 77% (61%–97%), and 51% (41%–62%). Of 70 patients who failed to achieve any PSA decline on prior abiraterone, 19 (27%) achieved ≥30% PSA decline with subsequent enzalutamide.

CONCLUSIONS

The activity of enzalutamide is blunted after abiraterone, after docetaxel, and still more after both, suggesting subsets of overlapping and distinct mechanisms of resistance.

Analysis of the correlation between endorectal MRI response to neoadjuvant chemotherapy and biochemical recurrence in patients with high-risk localized prostate cancer

BACKGROUND

Intermediate end points are desirable to expedite the integration of neoadjuvant systemic therapy into the treatment strategy for high-risk localized prostate cancer. Endorectal magnetic resonance imaging at 1.5 Tesla (1.5T erMRI) response has been utilized as an end point in neoadjuvant trials but has not been correlated with clinical outcomes.

METHODS

Data were pooled from two trials exploring neoadjuvant chemotherapy in high-risk localized prostate cancer. Trial 1 explored docetaxel for 6 months and Trial 2 explored docetaxel plus bevacizumab for 4.5 months, both before radical prostatectomy. erMRI was done at baseline and end of chemotherapy. 1.5T erMRI response, based upon T2W sequences, was recorded. Multivariable Cox regression was undertaken to evaluate the association between clinical parameters and biochemical recurrence.

RESULTS

There were 53 evaluable patients in the combined analysis: 20 (33%) achieved a PSA response, 16 (27%) achieved an erMRI partial response and 24 (40%) achieved an erMRI minor response. Median follow-up was 4.2 years, and 33 of 53 evaluable (62%) patients developed biochemical recurrence. On multivariable analysis, PSA response did not correlate with biochemical recurrence (hazard ratio=0.58, 95% confidence interval (CI) 0.25-1.33) and paradoxically erMRI response was associated with a significantly shorter time to biochemical recurrence (hazard ratio=2.47, 95% CI 1.00-6.13).

CONCLUSIONS

Response by 1.5T erMRI does not correlate with a decreased likelihood of biochemical recurrence in patients with high-risk localized prostate cancer treated with neoadjuvant docetaxel and may be associated with inferior outcomes. These data do not support the use of 1.5T erMRI response as a primary end point in neoadjuvant chemotherapy trials.

Incidence and risk of treatment-related mortality in cancer patients treated with the mammalian target of rapamycin inhibitors

BACKGROUND

Inhibition of the mammalian target of rapamycin (mTOR) is an established treatment for multiple malignancies. We carried out an up-to-date meta-analysis to determine the risk of fatal adverse events (FAEs) in cancer patients treated with mTOR inhibitors.

PATIENTS AND METHODS

PubMed, conferences and clinicaltrials.gov databases were searched for articles reported from January 1966 to June 2012. Eligible studies were limited to approved mTOR inhibitors (everolimus and temsirolimus) and reported on patients with cancer, randomized design and adequate safety profiles. Data extraction was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

RESULTS

In all, 3193 patients from eight randomized, controlled trials (RCTs) were included, 2236 from everolimus trials and 957 from temsirolimus trials. The relative risk (RR) of FAEs related to mTOR inhibitors use was 2.20 (95% CI, 1.25-3.90; P = 0.006) compared with control patients. On subgroup analysis, no difference in the rate of FAEs was found between everolimus and temsirolimus or between tumor types [renal cell carcinoma (RCC) versus non-RCC]. No evidence of publication bias was observed.

CONCLUSION

The use of mTOR inhibitors is associated with a small but higher risk of FAEs compared to control patients. In the appropriate clinical scenario, the use of these drugs remains justified in their approved indications.

Phase I study of the effects of renal impairment on the pharmacokinetics and safety of satraplatin in patients with refractory solid tumors

BACKGROUND

Satraplatin is an oral platinum analog with demonstrated activity in a range of malignancies. The current study was designed to evaluate the effect of varying degrees of renal impairment on the safety and pharmacokinetics (PKs) of satraplatin.

PATIENTS AND METHODS

Patients with advanced solid tumors, refractory to standard therapies, were eligible. The study included four cohorts of patients with varying levels of renal function, and eight patients per cohort: Group 1 (G1) = normal renal function; G2 = mild renal impairment [creatinine clearance (CrCl) 50-80 ml/min]; G3 = moderate impairment (CrCl 30 to <50 ml/min); G4 = severe impairment (CrCl <30 ml/min). Satraplatin was administered orally at 80 mg/m(2)/day on days 1-5 every 35 days.

RESULTS

A total of 32 patients were enrolled, 8 patients in each renal function group. Each group tolerated the dose of 80 mg/m(2)/day on days 1-5 every 35 days without the need for dose deescalation. The most common adverse events were fatigue (63%), nausea (56%), diarrhea (53%), anorexia (47%), constipation (38%), vomiting (28%), anemia, dyspnea, and thrombocytopenia (25%). There were no dose-limiting toxic effects in any study group. There was increased exposure to plasma platinum and plasma ultrafiltrate platinum in patients with moderate to severe renal impairment.

CONCLUSIONS

Satraplatin PKs was altered in patients with renal impairment. However, a corresponding increase in satraplatin-related toxic effects was not observed.

Comparative effectiveness of cisplatin-based and carboplatin-based chemotherapy for treatment of advanced urothelial carcinoma

BACKGROUND

Cisplatin-based chemotherapy is a standard treatment of metastatic urothelial carcinoma (UC), though carboplatin-based chemotherapy is frequently substituted due to improved tolerability. Because comparative effectiveness in clinical outcomes of cisplatin- versus carboplatin-based chemotherapy is lacking, a meta-analysis was carried out.

METHODS

PubMed was searched for articles published from 1966 to 2010. Eligible studies included prospective randomized trials evaluating cisplatin- versus carboplatin-based regimens in patients with metastatic UC. Individual patient data were not available and survival data were inconsistently reported. Therefore, the analysis focused on overall response (OR) and complete response (CR) rates. The Mantel-Haenszel method was used for combining trials and calculating pooled risk ratios (RRs).

RESULTS

A total of 286 patients with metastatic UC from four randomized trials were included. Cisplatin-based chemotherapy was associated with a significantly higher likelihood of achieving a CR [RR = 3.54; 95% confidence interval (CI) 1.48-8.49; P = 0.005] and OR (RR = 1.34; 95% CI 1.04-1.71; P = 0.02). Survival end points could not be adequately assessed due to inconsistent reporting among trials.

CONCLUSIONS

Cisplatin-based, as compared with carboplatin-based, chemotherapy significantly increases the likelihood of both OR and CR in patients with metastatic UC. The impact of improved response proportions on survival end points could not be assessed.

Meta-analysis of randomized trials comparing cisplatin versus carboplatin-based regimens for the first-line therapy of metastatic transitional cell carcinoma of the urothelium (TCCU)

247

Background: Cisplatin-based chemotherapy is the first-line treatment standard for metastatic TCCU, although carboplatin is substituted for cisplatin-ineligibility, tolerability, and ease of administration. Since definitive data comparing cisplatin- versus carboplatin-based chemotherapy are lacking, a meta-analysis of published randomized trials was performed.

Methods: PubMed was searched for articles published in the English language from 1966 until 2010 and abstracts presented at the American Society of Clinical Oncology Annual Meeting between 2000 and 2010 were searched to identify relevant trials. Eligible studies included prospective randomized trials evaluating cisplatin- versus carboplatin-based regimens in cisplatin-eligible patients with metastatic TCCU. Individual patient data were not available and progression and survival data were inconsistently reported. Therefore, the analysis focused on overall (OR) and complete response (CR). The Mantel-Haenszel method was used for combining trials and calculating pooled risk ratios (RR).

Results: A total of 286 patients with metastatic TCCU from 4 randomized trials (3 phase II and 1 phase III trial) were included. Chemotherapy regimens included MVEC (methotrexate, vinblastine, epirubicin, cisplatin) vs. MVECa (methotrexate, vinblastine, epirubicin, carboplatin), MVAC (methotrexate, vinblastine, doxorubicin, cisplatin) vs. MCAVI (methotrexate, carboplatin, vinblastine), MVAC vs. paclitaxel plus carboplatin, and gemcitabine plus cisplatin vs. gemcitabine plus carboplatin. Cisplatin-based chemotherapy was associated with a significant improvement in the likelihood of CR (RR=3.973 [95%CI: 1.562 – 10.110], p =0.004) and OR (RR=1.336 [95%CI: 1.043 – 1.712], p=0.025).

Conclusions: Cisplatin-based as compared with carboplatin-based combination chemotherapy significantly increases the likelihoods of both OR and CR, in patients with metastatic TCCU. In the absence of definitive phase 3 trials, these results support cisplatin-based regimens as the preferred first-line treatment for cisplatin-eligible patients with metastatic TCCU.

No significant financial relationships to disclose.

Phase I/II trial of concurrent sunitinib (SU) and image-guided radiotherapy (IGRT) followed by maintenance systemic therapy for patients with oligometastases

306

Background: Preclinical data suggest that SU enhances the efficacy of radiotherapy. We tested the combination of SU and hypofractionated IGRT in a cohort of patients with historically incurable distant metastases.

Methods: Eligible patients had 1 to 5 sites of metastatic solid tumors measuring ≤ 6 cm. The most common tumor types treated were head and neck, liver, lung, kidney, and prostate cancers. Patients were treated with concurrent SU (25 to 50 qd d 1–28) and IGRT (40 to 50 Gy in 10 fractions d 8–19). Following IGRT, patients could either receive maintenance SU (50 mg daily, 4 weeks on/2 weeks off starting on d 43) or alternate forms of systemic therapy. Most patients were treated with the recommended phase II dose of SU 37.5 mg and IGRT 50 Gy. Maintenance SU was used in 40% of patients.

Results: Between 2/07 and 6/08, 43 patients with 81 metastatic lesions were enrolled with a median follow up for surviving patients was 20.1 months (range, 5–37 months). The incidence of acute grade ≥ 3 toxicities was 33%, most commonly myelosuppression, bleeding and abnormal liver function tests. The 2-year estimates for local control and distant control were 74% and 43%, respectively. The 2-year estimates for progression- free survival and overall survival were 39% and 46%, respectively. To date, 15 (35%) patients were alive without evidence of disease, 6 (14%) were alive with distant metastases, 13 (30%) were dead from distant metastases, 1 (2%) was dead from local progression, 6 (14%) were dead from comorbid illness, and 2 (5%) were dead from treatment-related toxicities. Predictors of improved progression-free survival were genitourinary primary tumor (HR 0.18; p=0.04), IGRT dose > 40 Gy (HR 0.21; p=0.005), number of metastases (HR 2.22; p=0.006) and maintenance SU (HR 0.31; p=0.06). Flow cytometry demonstrates a significant reduction in immune suppressive myeloid derived suppressor cells and T regulatory cells in SU treated patients.

Conclusions: Concurrent SU and IGRT achieves durable local and distant control in a significant subset of patients with oligometastases, particularly patients with genitourinary primary tumors with ≤ 2 distant metastases.

[Table: see text]

Defining “cisplatin ineligible” patients with metastatic bladder cancer

238

Background: Cisplatin-based chemotherapy is standard first-line treatment for patients (pts) with metastatic urothelial carcinoma (UC). However, a large proportion of pts with UC are considered “unfit” for cisplatin, leading to clinical trials designed specifically for cisplatin-ineligible pts, with substantial variability in eligibility criteria. A clear and consistent definition of pts “unfit” for cisplatin-based therapy will aid in the development of standard eligibility criteria.

Methods: We assembled a panel of GU medical oncologists and followed a three-fold approach. First, we surveyed 120 international GU medical oncologists. Subsequently, we reviewed the literature regarding ‘cisplatin ineligibility‘ in solid tumors. Finally, the panel reconciled the survey results and available literature and generated a consensus definition.

Results: Responses were received from 65/120 (54%) of those surveyed. The survey results are shown in the Table . Reconciling the survey results with the available literature, the panel recommended the following be used to consistently define pts with metastatic UC “unfit” for cisplatin-based chemotherapy for clinical trial purposes: (1) ECOG performance status of 2 and/or (2) creatinine-clearance < 60 ml/min and/or (3) CTCAE Gr ≥ 2 hearing loss and/or (4) CTCAE Gr ≥ 2 neuropathy.

Conclusions: Substantial variability exists in investigators' definitions of pts with metastatic UC “unfit” for cisplatin. A consensus definition is proposed for standardization of eligibility criteria.

[Table: see text]

No significant financial relationships to disclose.

Evaluation of indibulin, a novel tubulin targeting-agent, in combination with capecitabine, with mathematically optimized dose scheduling

2538

Background: Indibulin (IDB) is a novel, orally available tubulin-targeting molecule that perturbs cancer cell migration and mitosis. It is active against taxane-resistant cell lines and is synergistic with 5-FU in vitro and in vivo. Two translational studies have been conducted: a Phase IB study of IDB in combination with capecitabine (CAP) in patients with advanced solid tumors, and mathematical modeling applying Norton-Simon models to breast carcinoma MX-1 xenografts to further develop Phase II dose. Methods: IDB is administered continuously starting at 400 mg BID. CAP is administered for 2 weeks with 1 week rest, starting at 875 mg/m2 BID. IDB and CAP are escalated to MTD: IDB 600 mg BID & CAP 1000 mg/m2 BID. Efficacy is evaluated every 9 weeks using RECIST. In the xenograft model indibulin is administered at dose levels from 12 to 28.7 mg/kg/day to nude mice carrying MX-1 breast carcinoma. Tumor growth is analyzed using a Gompertzian-type growth model to determine via calculus of variations the optimal schedule to maximize the efficacy/toxicity ratio. Results: To date, 7 patients have been treated and are evaluable for safety. Median age 62 yrs; ECOG ≤1; median prior therapies 3. Four patients are evaluable for efficacy and all have stable disease (3 for 6 cycles, 1 for 3 cycles). AEs include hand-and-foot syndrome (CAP), fatigue, vomiting, anorexia, and headache. Neither DLTs nor grade ≥3 AEs have been observed. In MX-1 xenografts, indibulin demonstrates linear dose-efficacy relationship over the range of 12 to 22 mg/kg. At all dose levels the first 5 days of administration are associated with a rapid accumulation of anticancer effect with lesser effects over the next 5 days to a peak of efficacy at day 10 Conclusions: IDB + CAP is well tolerated, without neurotoxicity. There is preliminary evidence of clinical activity even with this sub-optimal, continuous schedule of IDB. Formal analyses suggest that an intermittent schedule could optimize efficacy, minimize acquired resistance and allow for host recovery from drug-induced toxicity. Pre- clinical evaluation in a breast cancer model supports an intermittent dosing schedule to further increase the activity of IDB.

[Table: see text]

Target-specific, histology-independent, randomized discontinuation study of lapatinib in patients with HER2-amplified solid tumors

3541

Background: The current paradigm of histology-specific drug development may not be optimal in the era of targeted therapeutics. We sought to explore the activity of lapatinib, an oral tyrosine kinase inhibitor of HER2, with a trial design focused on the target rather than on tumor-type. Methods: Patients (pts) with HER2-amplified treatment-refractory metastatic gastro- esophageal (G/E), bladder (B), ovarian (O), or uterine (U) tumors were enrolled into a double-blinded randomized discontinuation study of lapatinib 1500 mg PO daily (malignancies selected based on reported frequencies of HER2 amplification). The planned sample size was 250 HER2+ pts, with the goal of then randomizing 100 pts with SD at week (wk) 12 to either lapatinib or placebo until progressive disease (PD). Pts who responded at wk 12 (CR or PR) continued on lapatinib; those who progressed were discontinued from study. Primary objectives were response rate at 12 wks and percentage of pts who remain progression free at 24 wks. Secondary objectives were duration of response, progression free survival (PFS) after randomization, and determination of the incidence of HER2 amplification in multiple tumor types. Futility analyses were preplanned to ensure feasibility of screening and of randomization (i.e. a sufficient rate of non- progression at 12 wks). Results: A total of 145 pts were screened (G/E=47, B=35, O=58, U=5); 42 were HER2-amplified (G/E=16, B=13, O=13, U=0) and 32 (G/E=13, B=9, O=10) were enrolled. At wk 12, 1 (3%) patient had a CR, 10 (31%) had SD, 19 (59%) had PD, and 2 (6%) were unknown. Median time to progression during open-label lapatinib was 78 days, 95% CI (42, 92). Only 7 pts with SD underwent randomization. Two pts with esophageal cancer remain on study; one (CR at wk 12) remains a CR at wk 60 and the other (SD at wk 12) remains with SD at wk 36. Low response rate coupled with slow screening and enrollment led to early study closure. Conclusions: Basing trial eligibility on a target, versus histologic classification, is challenging. While HER2 amplifications appear to be prevalent in select non-breast tumors, lapatinib monotherapy in refractory disease is associated with a low level of objective responses.

[Table: see text]

Prospective trial of ifosfamide, paclitaxel, and cisplatin (ITP) in patients with advanced non-transitional cell (non-TCC) carcinomas of the urothelial tract

4542

Background: Non-TCC’s account for 5–10% of urothelial tract tumors and are each characterized by unique demographics, risk factors, and patterns of spread. A unifying feature of these malignancies is their aggressive course and poor outcomes with standard chemotherapeutic regimens. Given the rarity of these tumors, no prospective data are available to guide management. Methods: Patients with unresectable/metastatic adenocarcinoma, squamous cell, small cell, sarcomatoid, and poorly differentiated carcinomas of the urothelial tract were eligible. Treatment consisted of: Paclitaxel 200 mg/m2 IV on day 1, cisplatin 70 mg/m2 IV on day 1, ifosfamide 1500 mg/m2 IV on days 1–3 + mesna. GCSF was administered with each cycle. Treatment was recycled every 3 weeks for a maximum of 6 cycles. The primary endpoint was the response rate. Results: Twenty patients (pts) were enrolled with the following histologic types: adenocarcinoma 11/20, squamous cell carcinoma 8/20, small cell carcinoma 1/20. Pts received a median of 4 cycles (range, 1–6). The grade 3–4 toxicities included neutropenia (6/20), anemia (9/20), thrombocytopenia (4/20), confusion (1/20), seizure (1/20), neuropathy (1/20), renal insufficiency (2/20), fatigue (2/20), and hyponatremia (1/20). Thirteen of the 20 pts have died. The median survival for pts with adenocarcinoma is 24 months (95% CI 9.6–32.4) and with squamous cell carcinoma is 8.4 months (95% CI 5.3-NR). Five pts achieved durable disease-free survival (1+, 2+, 4+, 6+, and 8+ years) after ITP ± surgical consolidation. Conclusions: ITP is an active regimen in pts with advanced non-TCC’s of the urothelial tract. To our knowledge, this is the first prospective study of a chemotherapeutic regimen in this patient population.

[Table: see text]

[Table: see text]

Study of afferent nerve terminals and fibers in the gerbil cochlea: distribution by size

The purpose of the present study was to determine if the synaptic terminals and nerve fibers in the gerbil cochlea fall into morphologically and spatially classified groups. In cats and guinea pigs, these groups, based on size, location on inner hair cell (IHC) and stratification within the osseous spiral lamina, have been found to correlate with spontaneous rate, threshold sensitivity and projection pattern to the cochlear nucleus. Thus, there may be anatomical data to suggest mechanisms for intensity coding of different frequencies of sound. Afferent nerve terminals contacting IHCs in the gerbil cochlea were analyzed with regard to size and location. Data were obtained from serial thin sections (700 for each IHC) cut perpendicular to the long axis of eight IHCs (two apical and two basal IHCs from two cochleas), observed and photographed using a transmission electron microscope. Results indicate that the percentage of modiolar versus pillar-side terminals around each IHC varies from cell to cell. In some cases, the smallest fibers were located on the modiolar side, but a consistent distribution of the smallest fibers on this side of the cell was not characteristic. While a size-based segregation of terminals does not appear around the perimeter of the IHC, modest size-based segregation of nerve fibers is found in the osseous spiral lamina. Perimeter measurements were made from myelinated fibers cut in cross-section, obtained from semi-thin sections in the distal (near the IHCs) and proximal (near the spiral ganglion) regions of the osseous spiral lamina. Best-fit line analysis indicates there is a modest nerve fiber size/vertical organization along the scala tympani/scala vestibuli (SV) axis of the nerve bundles within the osseous spiral lamina such that more of the smaller perimeter fibers are located on the SV side and more of the larger perimeter fibers are located on the ST side. Our data for terminals at the IHC are different from those seen in the cat; our data for nerve fibers in the osseous spiral lamina support those seen in the cat and guinea pig.