LuCAB: A phase I/II trial evaluating cabazitaxel in combination with [177Lu]Lu-PSMA-617 in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC)

TPS278

Background: [177Lu]Lu-PSMA-617 was recently FDA-approved for use in the post-taxane, post-antiandrogen setting in pts with mCRPC. Despite conferring a survival benefit, for many the treatment response is short, and progression is inevitable. One of the likely mechanisms limiting the durability of responses to [177Lu]Lu-PSMA-617 is heterogeneity in tumor PSMA expression. This can be screened for visually using PSMA and FDG PET/CT scans and inspecting for discordant disease, however, micrometastatic disease is unable to be evaluated in this way. In addition, [177Lu]Lu-PSMA-617 may not effectively target micrometastatic disease due to the longer path length of beta emitters. Cabazitaxel has radiosensitizing properties that may enhance the cytotoxic effect of [177Lu]Lu-PSMA-617, whilst also treating any PSMA-negative disease. We hypothesize that the combination of [177Lu]Lu-PSMA-617 and cabazitaxel will be well tolerated and lead to more durable responses. Methods: This single-centre, single-arm phase I/II trial will enrol 32-38 pts with mCRPC to evaluate the safety and preliminary efficacy of cabazitaxel and [177Lu]Lu-PSMA-617 in combination. Up to 6 doses of [177Lu]Lu-PSMA-617 (7.4 GBq) will be administered intravenously every 6 weeks. Cabazitaxel will be given concurrently (dose range 12.5mg/m2 - 20mg/m2), on Day 2 and Day 23 of each 6-week cycle. The dose of cabazitaxel will be escalated using a traditional 3+3 design. Key eligibility criteria include a diagnosis of mCRPC with PSMA-positive disease on PSMA PET/CT (SUVmax ≥15), with no evidence of diffuse marrow disease or sites of discordance on FDG PET/CT. Pts must have progressed after prior docetaxel and a second-generation antiandrogen, have adequate bone marrow and organ function and an ECOG performance status of 0-1. The primary objective is to establish the maximum tolerated dose of cabazitaxel and [177Lu]Lu-PSMA-617. Secondary objectives include measuring the frequency and severity of adverse events, assessment of efficacy through PSA 50% response rate, radiographic and PSA progression-free survival, overall survival, objective tumor response rate, and evaluation of pain and health-related quality of life over the first 12 months. Bloods will be taken at baseline, during treatment and at progression for ctDNA analysis, the results of which will be correlated with baseline pt and disease characteristics, and response outcomes, to determine biomarkers of treatment response and resistance. Pt recruitment commenced in August 2022 and will continue for 18 months. Clinical trial information: NCT05340374 .

AlphaBet: A phase I/II trial evaluating the combination of radium-223 and [177Lu]Lu-PSMA-I&T in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC)

TPS280

Background: [177Lu]Lu-PSMA-I&T (LuPSMA) is a small molecule radioligand that delivers radiation via beta-particulate emission to cells expressing prostate-specific membrane antigen (PSMA). Despite a survival benefit in mCRPC, responses for many are not durable, with the majority of pts developing progressive osseous disease. Due to the lack of crossfire radiation in micrometastatic disease, small cancer cell clusters in the bone marrow may not receive an adequate dose of radiation from 177Lu to induce cytotoxic double-stranded DNA breaks. Alpha-emitters have a shorter path length (≤100 µm) and higher linear energy transfer, making them better suited for treating micrometastatic disease. As a calcium-mimetic, radium-223 (223Ra) is a bone-specific alpha-emitter which targets osteoblastic bone metastases. We hypothesise that the combination of LuPSMA with 223Ra will be well tolerated and lead to improved response durability. Methods: This phase I/II, single-arm, single-centre study will enrol 36 patients with mCRPC who have progressed on a prior second-generation antiandrogen. Up to 6 cycles of LuPSMA (7.4 GBq) and 223Ra (28 kBq/kg - 55 kBq/kg) will be given intravenously every 6 weeks, along with background androgen deprivation and bone protective therapy. Key eligibility criteria include a diagnosis of mCRPC with at least two untreated bone metastases visible on bone scintigraphy and PSMA-positive disease on PSMA PET/CT (SUVmax ≥20). Sites of FDG-positive disease must be either PSMA-positive or have increased uptake on bone scan. Other eligibility criteria include an ECOG status of 0-2, and adequate bone marrow and organ function. Patients treated with more than one line of chemotherapy for metastatic prostate cancer are not eligible. Blood samples and biopsies will be taken at baseline, on treatment, and at progression to develop tumor- and immune-based biomarkers that predict treatment response and associated survival benefit. A traditional 3+3 dose-escalation model will be utilized initially, escalating the dose of 223Ra. The dose of LuPSMA will remain fixed. The co-primary objectives of this study are to determine the maximum tolerated dose of 223Ra when combined with LuPSMA, and the 50% PSA response rate. Secondary objectives include measuring the frequency and severity of adverse events, assessment of efficacy through overall, radiographic and PSA progression-free survival, overall survival, objective tumor response rate, and evaluation of pain and health-related quality of life. Enrolment commenced in September 2022 and will continue for 24 months. Clinical trial information: NCT05383079 .

AlphaBet: Combination of Radium-223 and [17 7Lu]Lu-PSMA-I&T in men with metastatic castration-resistant prostate cancer (clinical trial protocol)

BACKGROUND

[177Lu]Lu-PSMA is a radioligand therapy used in metastatic castration-resistant prostate cancer (mCRPC). Despite a survival benefit, the responses for many patients receiving [177Lu]Lu-PSMA are not durable, and all patients eventually develop progressive disease. The bone marrow is the most common site of progression. Micrometastases in this area likely receive an inadequate dose of radiation, as the emitted beta-particles from 177Lu travel an average range of 0.7 mm in soft tissue, well beyond the diameter of micrometastases. Radium-223 (223Ra) is a calcium-mimetic and alpha-emitting radionuclide approved for use in men with mCRPC with bone metastases. The range of emitted alpha particles in soft tissue is much shorter (≤100 μm) with high linear energy transfer, likely more lethal for osseous micrometastases. We anticipate that combining a bone-specific alpha-emitter with [177Lu]Lu-PSMA will improve eradication of micrometastatic osseous disease, and thereby lead to higher and longer responses.

METHODS

This is a single-center, single-arm phase I/II trial evaluating the combination of 223Ra and [177Lu]Lu-PSMA-I&T in men with mCRPC. Thirty-six patients will receive 7.4 GBq of [177Lu]Lu-PSMA-I&T, concurrently with 223Ra in escalating doses (28 kBq/kg - 55kBq/kg), both given intravenously every six weeks for up to six cycles. Eligible patients will have at least two untreated bone metastases visible on bone scintigraphy, and PSMA-positive disease on PSMA PET scan. Patients must have adequate bone marrow and organ function and be willing to undergo tumor biopsies. Patients with discordant disease visible on FDG PET scan (defined as FDG positive disease with minimal or no PSMA expression and no uptake on bone scan) will be excluded. Other key exclusion criteria include the presence of diffuse marrow disease, prior treatment with 223Ra or [177Lu]Lu-PSMA, or more than one prior line of chemotherapy for prostate cancer. The co-primary objectives of this study are to determine the maximum tolerated dose of 223Ra when combined with [177Lu]Lu-PSMA-I&T and the 50% PSA response rate.

CONCLUSION

The AlphaBet trial is a phase I/II study combining 223Ra with [177Lu]Lu-PSMA-I&T in patients with mCRPC. We aim to enroll the first patient in Q3 2022, and recruitment is anticipated to continue for 24 months.

STUDY REGISTRATION

NCT05383079.

Ibrutinib plus Venetoclax for the Treatment of Mantle-Cell Lymphoma

BACKGROUND

Both the BTK inhibitor ibrutinib and the BCL2 inhibitor venetoclax are active as monotherapy in the treatment of mantle-cell lymphoma. Complete response rates of 21% have been observed for each agent when administered as long-term continuous therapy. Preclinical models predict synergy in combination.

METHODS

We conducted a single-group, phase 2 study of daily oral ibrutinib and venetoclax in patients, as compared with historical controls. Patients commenced ibrutinib monotherapy at a dose of 560 mg per day. After 4 weeks, venetoclax was added in stepwise, weekly increasing doses to 400 mg per day. Both drugs were continued until progression or an unacceptable level of adverse events. The primary end point was the rate of complete response at week 16. Minimal residual disease (MRD) was assessed by flow cytometry in bone marrow and by allele-specific oligonucleotide-polymerase chain reaction (ASO-PCR) in blood.

RESULTS

The study included 24 patients with relapsed or refractory mantle-cell lymphoma (23 patients) or previously untreated mantle-cell lymphoma (1 patient). Patients were 47 to 81 years of age, and the number of previous treatments ranged from none to six. Half the patients had aberrations of TP53, and 75% had a high-risk prognostic score. The complete response rate according to computed tomography at week 16 was 42%, which was higher than the historical result of 9% at this time point with ibrutinib monotherapy (P<0.001). The rate of complete response as assessed by positron-emission tomography was 62% at week 16 and 71% overall. MRD clearance was confirmed by flow cytometry in 67% of the patients and by ASO-PCR in 38%. In a time-to-event analysis, 78% of the patients with a response were estimated to have an ongoing response at 15 months. The tumor lysis syndrome occurred in 2 patients. Common side effects were generally low grade and included diarrhea (in 83% of the patients), fatigue (in 75%), and nausea or vomiting (in 71%).

CONCLUSIONS

In this study involving historical controls, dual targeting of BTK and BCL2 with ibrutinib and venetoclax was consistent with improved outcomes in patients with mantle-cell lymphoma who had been predicted to have poor outcomes with current therapy. (Funded by Janssen and others; AIM ClinicalTrials.gov number, NCT02471391 .).

Combination ibrutinib (Ibr) and venetoclax (Ven) for the treatment of mantle cell lymphoma (MCL): Primary endpoint assessment of the phase 2 AIM study

7520

Background: Both ibr and ven have activity in relapsed/refractory (R/R) MCL, but complete remissions (CR) are attained in <25% with either. We sought to determine the activity of the combination in an investigator-initiated, phase 2 study. Methods: Enrolment of 24 patients (pts) with R/R (n=23) or frontline (n=1) MCL completed in 09/16. Pts received 4 weeks of ibr (560mg/d), followed by introduction of ven (weekly ramp-up to target 400mg/d). The primary endpoint was CR rate at week 16, as assessed by PET/CT, BMAT, flow & molecular MRD, and endoscopy (if baseline gut involvement). Response was calculated separately with and without knowledge of the PET result by IWG criteria (Cheson JCO 2007), in order to compare with published studies (ibr, 9% CR at wk16; ven, best CR rate 21%). Results: Median age of pts was 68 (range, 47-81) years. For the R/R pts (n=23), median lines of prior therapy was 2 (1-6), 48% were refractory to last treatment, and 30% had failed previous autologous SCT. As of data cutoff on Jan 11 2017, 18 pts remain on therapy, and 6 stopped treatment due to progressive disease (4), adverse event (1) or unrelated death (1). At week 16, ORR was 71% (63% CR) and 80% of complete responders were flow-cytometry negative in the marrow (sensitivity 10-3 to 10-4). Using CT without PET, the comparison responses were CR 42%, CRu 17%, PR 17% (ORR 78%). After a median follow-up of 8.3 (range 1.4-17.7) months, the 8-month estimates of PFS and OS months are 74% and 81%. Adverse events ≥20%, irrespective of attribution, were fatigue (71%), diarrhea (67%), nausea (50%), URTI (38%), gastro-esophageal reflux (33%), neutropenia (33%), cough (25%) and bruising (21%); with the exception of neutropenia (25% grade 3-4), these were predominantly grade 1-2 in severity. Tumour lysis syndrome occurred in 2 pts with high tumour burden, leading to revision of the protocol ven starting dose from 50mg, to 20mg/d. Conclusions: The combination of ibr and ven was tolerable and achieved CR rate of 63% at week 16 in pts with MCL. The efficacy results compare favorably with historical results, and warrant further phase III investigation. Clinical trial information: NCT02471391.

Idarubicin Dose Escalation During Consolidation Therapy for Adult Acute Myeloid Leukemia

Purpose Higher doses of the anthracycline daunorubicin during induction therapy for acute myeloid leukemia (AML) have been shown to improve remission rates and survival. We hypothesized that improvements in outcomes in adult AML may be further achieved by increased anthracycline dose during consolidation therapy. Patients and Methods Patients with AML in complete remission after induction therapy were randomly assigned to receive two cycles of consolidation therapy with cytarabine 100 mg/m² daily for 5 days, etoposide 75 mg/m² daily for 5 days, and idarubicin 9 mg/m² daily for either 2 or 3 days (standard and intensive arms, respectively). The primary end point was leukemia-free survival (LFS). Results Two hundred ninety-three patients 16 to 60 years of age, excluding those with core binding factor AML and acute promyelocytic leukemia, were randomly assigned to treatment groups (146 to the standard arm and 147 to the intensive arm). Both groups were balanced for age, karyotypic risk, and FLT3-internal tandem duplication and NPM1 gene mutations. One hundred twenty patients in the standard arm (82%) and 95 patients in the intensive arm (65%) completed planned consolidation ( P < .001). Durations of severe neutropenia and thrombocytopenia were prolonged in the intensive arm, but there were no differences in serious nonhematological toxicities. With a median follow-up of 5.3 years (range, 0.6 to 9.9 years), there was a statistically significant improvement in LFS in the intensive arm compared with the standard arm (3-year LFS, 47% [95% CI, 40% to 56%] v 35% [95% CI, 28% to 44%]; P = .045). At 5 years, the overall survival rate was 57% in the intensive arm and 47% in the standard arm ( P = .092). There was no evidence of selective benefit of intensive consolidation within the cytogenetic or FLT3-internal tandem duplication and NPM1 gene mutation subgroups. Conclusion An increased cumulative dose of idarubicin during consolidation therapy for adult AML resulted in improved LFS, without increased nonhematologic toxicity.

Use of arsenic trioxide in remission induction and consolidation therapy for acute promyelocytic leukaemia in the Australasian Leukaemia and Lymphoma Group (ALLG) APML4 study: a non-randomised phase 2 trial

BACKGROUND

Initial treatment of acute promyelocytic leukaemia traditionally involves tretinoin (all-trans retinoic acid) combined with anthracycline-based risk-adapted chemotherapy, with arsenic trioxide being the treatment of choice at relapse. To try to reduce the relapse rate, we combined arsenic trioxide with tretinoin and idarubicin in induction therapy, and used arsenic trioxide with tretinoin as consolidation therapy.

METHODS

Patients with previously untreated genetically confirmed acute promyelocytic leukaemia were eligible for this study. Eligibilty also required Eastern Cooperative Oncology Group performance status 0-3, age older than 1 year, normal left ventricular ejection fraction, Q-Tc interval less than 500 ms, absence of serious comorbidity, and written informed consent. Patients with genetic variants of acute promyelocytic leukaemia (fusion of genes other than PML with RARA) were ineligible. Induction comprised 45 mg/m(2) oral tretinoin in four divided doses daily on days 1-36, 6-12 mg/m(2) intravenous idarubicin on days 2, 4, 6, and 8, adjusted for age, and 0·15 mg/kg intravenous arsenic trioxide once daily on days 9-36. Supportive therapy included blood products for protocol-specified haemostatic targets, and 1 mg/kg prednisone daily as prophylaxis against differentiation syndrome. Two consolidation cycles with tretinoin and arsenic trioxide were followed by maintenance therapy with oral tretinoin, 6-mercaptopurine, and methotrexate for 2 years. The primary endpoints of the study were freedom from relapse and early death (within 36 days of treatment start) and we assessed improvement compared with the 2 year interim results. To assess durability of remission we compared the primary endpoints and disease-free and overall survival at 5 years in APML4 with the 2 year interim APML4 data and the APML3 treatment protocol that excluded arsenic trioxide. This study is registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12605000070639.

FINDINGS

124 patients were enrolled between Nov 10, 2004, and Sept 23, 2009, with data cutoff of March 15, 2012. Four (3%) patients died early. After a median follow-up of 4·2 years (IQR, 3·2-5·2), the 5 year freedom from relapse was 95% (95% CI 89-98), disease-free survival was 95% (89-98), event-free survival was 90% (83-94), and overall survival was 94% (89-97). The comparison with APML3 data showed that hazard ratios were 0·23 (95% CI 0·08-0·64, p=0·002) for freedom from relapse, 0·21 (0·07-0·59, p=0·001) for disease-free survival, 0·34 (0·16-0·69, p=0·002) for event-free survival, and 0·35 (0·14-0·91, p=0·02) for overall survival.

INTERPRETATION

Incorporation of arsenic trioxide in initial therapy induction and consolidation for acute promyelocytic leukaemia reduced the risk of relapse when compared with historical controls. This improvement, together with a non-significant reduction in early deaths and absence of deaths in remission, translated into better event-free and overall survival.

FUNDING

Phebra.

Adjuvant lymph-node field radiotherapy versus observation only in patients with melanoma at high risk of further lymph-node field relapse after lymphadenectomy (ANZMTG 01.02/TROG 02.01): 6-year follow-up of a phase 3, randomised controlled trial

BACKGROUND

Adjuvant radiotherapy is recommended for patients with melanoma after lymphadenectomy. We previously showed this treatment reduced risk of repeat lymph-node field cancer in patients with a high risk of recurrence but had no effect on overall survival. Here, we aim to update the relapse and survival data from that trial and assess quality of life and toxic effects.

METHODS

In the ANZMTG 01.02/TROG 02.01 randomised controlled trial, we enrolled patients who had undergone lymphadenectomy for a palpable lymph-node field relapse and were at high risk of recurrence at 16 hospitals (11 in Australia, three in New Zealand, one in Netherlands, and one in Brazil). We randomly assigned patients (1:1) to adjuvant radiotherapy (48 Gy in 20 fractions, given over a maximum of 30 days) or observation, stratified by institution, areas of lymph-node field (parotid and cervical, axilla, or groin), number of involved nodes (≤3 vs >3), maximum involved node diameter (≤4 cm vs >4 cm), and extent of extracapsular extension (none, limited, or extensive). Participants, those giving treatment, and those assessing outcomes were not masked to treatment allocation, but participants were unaware of each other's treatment allocation. In this follow-up, we assessed outcomes every 3 months from randomisation for the first 2 years, then every 6 months up to 5 years, then annually. The primary endpoint was lymph-node field relapse as a first relapse, assessed in patients without major eligibility infringements (determined by an independent data monitoring committee). We assessed late adverse effects (occurring >90 days after surgery or start of radiotherapy) with standard criteria in the as-treated population. This study is registered with ClinicalTrials.gov, number NCT00287196.

FINDINGS

Between March 21, 2003, and Nov 15, 2007, we randomly assigned 123 patients to adjuvant radiotherapy (109 eligible for efficacy assessments) and 127 to observation (108 eligible). The final follow-up date was Nov 15, 2011. Median follow-up was 73 months (IQR 61-91). 23 (21%) relapses occurred in the adjuvant radiotherapy group compared with 39 (36%) in the observation group (adjusted hazard ratio [HR] 0·52 [95% CI 0·31-0·88], p=0·023). Overall survival (HR 1·27 [95% CI 0·89-1·79], p=0·21) and relapse-free survival (0·89 [0·65-1·22], p=0·51) did not differ between groups. Minor, long-term toxic effects from radiotherapy (predominantly pain, and fibrosis of the skin or subcutaneous tissue) were common, and 20 (22%) of 90 patients receiving adjuvant radiotherapy developed grade 3-4 toxic effects. 18 (20%) of 90 patients had grade 3 toxic effects, mainly affecting skin (nine [10%] patients) and subcutaneous tissue (six [7%] patients). Over 5 years, a significant increase in lower limb volumes was noted after adjuvant radiotherapy (mean volume ratio 15·0%) compared with observation (7·7%; difference 7·3% [95% CI 1·5-13·1], p=0·014). No significant differences in upper limb volume were noted between groups.

INTERPRETATION

Long-term follow-up supports our previous findings. Adjuvant radiotherapy could be useful for patients for whom lymph-node field control is a major issue, but entry to an adjuvant systemic therapy trial might be a preferable first option. Alternatively, observation, reserving surgery and radiotherapy for a further recurrence, might be an acceptable strategy.

FUNDING

National Health and Medical Research Council of Australia, Cancer Council Australia, Melanoma Institute Australia, and the Cancer Council South Australia.

Adjuvant radiotherapy versus observation alone for patients at risk of lymph-node field relapse after therapeutic lymphadenectomy for melanoma: a randomised trial

BACKGROUND

The use of radiotherapy after therapeutic lymphadenectomy for patients with melanoma at high risk of further lymph-node field and distant recurrence is controversial. Decisions for radiotherapy in this setting are made on the basis of retrospective, non-randomised studies. We did this randomised trial to assess the effect of adjuvant radiotherapy on lymph-node field control in patients who had undergone therapeutic lymphadenectomy for metastatic melanoma in regional lymph nodes.

METHODS

This randomised controlled trial included patients from 16 hospitals in Australia, New Zealand, the Netherlands, and Brazil. To be eligible for this trial, patients had to be at high risk of lymph-node field relapse, judged on the basis of number of nodes involved, extranodal spread, and maximum size of involved nodes. After lymphadenectomy, randomisation was done centrally by computer and patients assigned by telephone in a ratio of 1:1 to receive adjuvant radiotherapy of 48 Gy in 20 fractions or observation, with institution, lymph-node field, number of involved nodes, maximum node diameter, and extent of extranodal spread as minimisation factors. Participants, those giving treatment, and those assessing outcomes were not masked to treatment allocation. The primary endpoint was lymph-node field relapse (as a first relapse), analysed for all eligible patients. The study is registered at ClinicalTrials.gov, number NCT00287196. The trial is now closed and follow-up discontinued.

FINDINGS

123 patients were randomly allocated to the adjuvant radiotherapy group and 127 to the observation group between March 20, 2002, and Sept 21, 2007. Two patients withdrew consent and 31 had a major eligibility infringement as decided by the independent data monitoring committee, resulting in 217 eligible for the primary analysis (109 in the adjuvant radiotherapy group and 108 in the observation group). Median follow-up was 40 months (IQR 27-55). Risk of lymph-node field relapse was significantly reduced in the adjuvant radiotherapy group compared with the observation group (20 relapses in the radiotherapy group vs 34 in the observation group, hazard ratio [HR] 0·56, 95% CI 0·32-0·98; p=0·041), but no differences were noted for relapse-free survival (70 vs 73 events, HR 0·91, 95% CI 0·65-1·26; p=0·56) or overall survival (59 vs 47 deaths, HR 1·37, 95% CI 0·94-2·01; p=0·12). The most common grade 3 and 4 adverse events were seroma (nine in the radiotherapy group vs 11 in the observation group), radiation dermatitis (19 in the radiotherapy group), and wound infection (three in the radiotherapy group vs seven in the observation group).

INTERPRETATION

Adjuvant radiotherapy improves lymph-node field control in patients at high risk of lymph-node field relapse after therapeutic lymphadenectomy for metastatic melanoma. Adjuvant radiotherapy should be discussed with patients at high risk of relapse after lymphadenectomy.

FUNDING

National Health and Medical Research Council of Australia, Cancer Australia, Melanoma Institute Australia, Cancer Council of South Australia.

Assessment of the pharmacological properties of 5-methoxyindole derivatives at 5-HT4 receptors

Objectives

The aim was to examine the biological activity of 5-methoxytryptamine derivatives at the 5-hydroxytryptamine (5-HT)4 receptor to explore the effect of substitution on the aliphatic amine of the 5-methoxyamine scaffold.

Methods

Three compounds were tested for affinity at the 5-HT4 receptor by radioligand binding and functional activity using guinea-pig ileum and human colon circular muscle preparations and also in the mouse whole gut transit test.

Key findings

The three compounds all had agonist properties at the 5-HT4 receptor but their efficacy differed in the different functional tests. Compound 3 had the highest affinity for the 5-HT4 receptor and was a full agonist at relaxing human colon circular muscle with efficacy closest to 5-HT. Compounds 1 and 2 were partial agonists in this assay with lower efficacies; compound 2 was a full agonist in the guinea-pig ileum assay whereas compound 3 was a partial agonist. Compounds 1 and 2 also showed activity in the mouse gut transit assay while compound 3 had no activity.

Conclusions

Of the compounds tested, compound 3 was the most promising 5-HT4 receptor agonist and the results highlight the value of using human tissue in functional tests when assessing compounds for potential activity.

Results of the APML3 trial incorporating all-trans-retinoic acid and idarubicin in both induction and consolidation as initial therapy for patients with acute promyelocytic leukemia

BACKGROUND

Initial therapy for patients with acute promyelocytic leukemia most often involves the combination of all-trans-retinoic acid with anthracycline-based chemotherapy. The role of non-anthracycline drugs in induction and consolidation is less well-established and varies widely between different cooperative group protocols.

DESIGN AND METHODS

In an attempt to minimize relapse and maximize survival for patients with newly diagnosed acute promyelocytic leukemia, the Australasian Leukaemia and Lymphoma Group utilized all-trans-retinoic acid and idarubicin as anti-leukemic therapy for both induction and consolidation. The protocol (known as APML3) was subsequently amended to incorporate maintenance with all-trans-retinoic acid, methotrexate and 6-mercaptopurine.

RESULTS

Eight (8%) of 101 patients died within 30 days, and 91 (90%) achieved complete remission. With a median estimated potential follow-up of 4.6 years, 4-year overall survival was 84%, and 71% of the patients remained in remission at 4 years. The cumulative incidence of all relapses was 28.1%, with 15 of the 25 relapses initially identified as an isolated molecular relapse. Both FLT3 mutations (internal tandem duplications and codon 835/836 kinase domain mutations) and increased white cell count at diagnosis were associated with inferior overall survival, but in multivariate analyses only FLT3 mutations remained significant (hazard ratio 6.647, P=0.005). Maintenance therapy was significantly associated with improved remission duration (hazard ratio 0.281, P<0.001) and disease-free survival (hazard ratio 0.290, P<0.001).

CONCLUSIONS

The combination of all-trans-retinoic acid and just two cycles of idarubicin followed by triple maintenance produced durable remissions in most patients, but patients with high-risk disease, especially those with FLT3 mutations, require additional agents or alternative treatment approaches. The significant reduction in relapse seen after the addition of maintenance to the protocol supports a role for maintenance in the context of relatively low chemotherapy exposure during consolidation. (actr.org.au identifier: ACTRN12607000410459).

Adjuvant chemoradiation for gastric cancer using epirubicin, cisplatin, and 5-fluorouracil before and after three-dimensional conformal radiotherapy with concurrent infusional 5-fluorouracil: a multicenter study of the Trans-Tasman Radiation Oncology Group

PURPOSE

The INT0116 study has established postoperative chemoradiotherapy as the standard of care for completely resected gastric adenocarcinoma. However, the optimal chemoradiation regimen remains to be defined. We conducted a prospective, multicenter study to evaluate an alternative chemoradiation regimen that combines more current systemic treatment with modern techniques of radiotherapy delivery.

METHODS AND MATERIALS

Patients with adenocarcinoma of the stomach who had undergone an R0 resection were eligible. Adjuvant therapy consisted of one cycle of epirubicin, cisplatin, and 5-FU (ECF), followed by radiotherapy with concurrent infusional 5-FU, and then two additional cycles of ECF. Radiotherapy was delivered using precisely defined, multiple-field, three-dimensional conformal techniques.

RESULTS

A total of 54 assessable patients were enrolled from 19 institutions. The proportion of patients commencing Cycles 1, 2, and 3 of ECF chemotherapy were 100%, 81%, and 67% respectively. In all, 94% of patients who received radiotherapy completed treatment as planned. Grade 3/4 neutropenia occurred in 66% of patients with 7.4% developing febrile neutropenia. Most neutropenic episodes (83%) occurred in the post-radiotherapy period during cycles 2 and 3 of ECF. Grade 3/4 gastrointestinal toxicity occurred in 28% of patients. In all, 35% of radiotherapy treatment plans contained protocol deviations that were satisfactorily amended before commencement of treatment. At median follow-up of 36 months, the 3-year overall survival rate was estimated at 61.6%.

CONCLUSIONS

This adjuvant regimen using ECF before and after three-dimensional conformal chemoradiation is feasible and can be safely delivered in a cooperative group setting. A regimen similar to this is currently being compared with the INT0116 regimen in a National Cancer Institute-sponsored, randomized Phase III trial.

Flexible low-intensity combination chemotherapy for elderly patients with acute myeloid leukaemia: a multicentre, phase II study

OBJECTIVE

To evaluate the efficacy of a flexible low-intensity combination chemotherapy (FLICC) protocol in a multicentre, phase II study of elderly patients with acute myeloid leukaemia (AML).

METHOD

Twenty-five patients aged 61-78 years (median 70 years) with de novo (n = 17) or secondary (n = 8) AML (cytogenetic risk: favourable 2, intermediate 18, adverse 2, unknown 3) from eight Australian centres were enrolled. Treatment comprised mitoxantrone 6 mg/m(2) intravenously daily for 3 days, cytarabine 10mg/m(2) subcutaneously every 12 hours for 7-14 days and etoposide 100mg orally for 7-14 days.

RESULTS

The treatment was generally well tolerated, and 13 patients (52%) achieved a complete remission (CR). One patient achieved a partial remission but died on day 28 due to pneumonia. Five patients (20%) had no response, whilst six (24%) died on or before day 30 and so were not evaluable. The median overall survival (OS) was 6.5 months, and the median remission duration was 7.7 months. Estimated 1-year survival was 32%, but patients achieving CR had an estimated 1-year survival of 64%, whereas none in the non-CR group survived to 1 year. Two of the CR patients have survived beyond 2 years. OS was significantly shorter in the adverse cytogenetic risk group of patients compared with the favourable- and intermediate-risk groups, with the rates of death relative to the adverse group being 0.02 and 0.08 in the favourable- and intermediate-risk groups, respectively. There was no significant association between CR rate and pre-existing myelodysplasia or the presence of multilineage dysplasia. The median durations of significant neutropenia (<0.5 x 10(9)/L) and thrombocytopenia (<20 x10(9)/L) with the first course of treatment in the 19 evaluable patients were 19 days (range 12-26) and 11 days (range 1-25), respectively. The median duration of stay in the hospital was 27 days (range 14-42). These values were much shorter for the second course of treatment: 6 days, 5 days and 15 days, respectively.

CONCLUSION

The findings of this multicentre, phase II study validate the previously reported single-institution experience with the FLICC protocol in elderly patients with AML. The clinical outcome with this protocol is comparable to those reported with more aggressive anti-leukaemia protocols.

A randomized, double-blind, crossover trial of the effect of oxygen on dyspnea in patients with advanced cancer

Dyspnea is a common symptom in palliative care. Despite this, there is uncertainty regarding the role of oxygen to treat the symptom in patients with advanced illness. This randomized, double-blind, crossover trial examined the effect of oxygen versus air on the relief of dyspnea in patients with advanced cancer. Following the blinded administration of air and oxygen via nasal prongs, 51 patients rated dyspnea and indicated preferences for the blinded treatments. On average, patients improved symptomatically with both air and oxygen, and there were no significant differences between the treatments. The subgroup of 17 hypoxic patients overall did not demonstrate a significant difference between air and oxygen, despite having improved oxygen saturations when administered oxygen. Hypoxia was corrected in 13 of 17 patients using the treatment dose of 4 L/min of oxygen. The experience of dyspnea is a complex, multifactorial phenomenon, with oxygen tension not correlating with the subjective experience. The administration of either air or oxygen via nasal prongs on average confers improvement of the symptom.

Risk-reducing surgery in women with familial susceptibility for breast and/or ovarian cancer

This multicentre study examined uptake of bilateral risk-reducing mastectomy (BRRM) and bilateral risk-reducing oophorectomy (BRRO) in women at increased risk for breast and/or ovarian cancer who had attended a familial cancer clinic (FCC) between January 1999 and June 2000. Eligible women (N=396), were mailed a questionnaire assessing: BRRM and BRRO details; risk perception; and anxiety. Family history, genetic testing and risk assessment were abstracted from medical records. Surgery was cross-tabulated with demographics, risk perception and anxiety with either Fisher's exact test or the exact form of the Mantel-Haenszel test (for ordinal factors) used to investigate for associations. Ordinal logistic regression was used with continuous-scale covariates. In total, 130 women were lost to follow-up leaving 266; of these 182 (68.4%) responded. Mean follow-up time was 3.73 years. The BRRM rate was 4.4%; with no difference found between moderate and high-risk groups. BRRM was associated with increasing numbers of affected relatives (P=0.025). BRRO was undertaken by 17.3%, more commonly in women older than 40 years of age (P=0.023) and with a BRCA1/2 mutation (P=0.017). Women who underwent BRRM (P=0.052) or BRRO (P<0.001) had a lower post-procedure risk perception than those who did not. During the timeframe of this study, risk-reducing surgery was undertaken by a small percentage of Australian women at increased risk for breast and/or ovarian cancer who attended FCCs. Family cancer history and mutation status were associated with uptake.

A multicenter phase II trial of thalidomide and celecoxib for patients with relapsed and refractory multiple myeloma

Preclinical data indicates that cyclooxygenase-2 (COX-2) inhibition impairs plasma cell growth and potentially synergizes with thalidomide. We performed a trial in previously treated patients with myeloma using thalidomide up to a maximum dose of 800 mg/d with celecoxib (400 mg bid). Outcomes were compared with a prior trial of thalidomide. Sixty-six patients with median age of 67 (range, 43-85) received a median dose of thalidomide and celecoxib of 400 and 800 mg/d, respectively, with median durations of treatment of 27 and 13 weeks, respectively. The most common toxicities associated with premature discontinuation of celecoxib (n = 30 of 53, 57%) were fluid retention and deterioration of renal function. Overall response rate (RR) was 42% and with 20 months median follow-up; the actuarial median progression-free survival and overall survival were 6.8 and 21.4 months, respectively. Unlike our prior study, age >65 years was not predictive of inferior RR due to improvement in RR in older patients with the combination (37% versus 15%, P = 0.08). The RR was superior in patients who received a total dose of celecoxib exceeding 40 g in the first 8 weeks of therapy (62% versus 30%, P = 0.021). Progression-free survival and overall survival were also improved. Other predictors for inferior progression-free survival were age >65 years (P = 0.016) and elevated beta(2)-microglobulin (P = 0.017). This study provides evidence that the addition of high-dose celecoxib adds to the antimyeloma activity of thalidomide but this comes with unacceptable toxicity. Future studies should use newer COX-2 inhibitors with thalidomide, or their respective derivatives.

Long-term follow-up of salvage radiotherapy in Hodgkin’s lymphoma after chemotherapy failure

PURPOSE

To evaluate the long-term results of salvage radiotherapy (SRT) for Hodgkin's lymphoma after chemotherapy failure.

METHODS AND MATERIALS

We reviewed 81 patients undergoing SRT for persistent or recurrent Hodgkin's lymphoma after chemotherapy; 19 also received conventional-dose salvage chemotherapy.

RESULTS

At SRT, the median patient age was 31 years. Of the 81 patients, 81% had Stage I-II, 25.9% had B symptoms, 14.8% had bulky disease, and 7.4% had extranodal disease. A less than a complete response (CR) to the last chemotherapy regimen occurred in 47%. SRT was generally limited to one side of the diaphragm, and the median dose was 36 Gy. After SRT, 75% of patients achieved a CR, with 82% retaining durable in-field control. In-field failure was associated with less than a CR to the last chemotherapy regimen (p = 0.0287). Most failures were at distant sites, with 60% in previously involved sites. The 10-year freedom from treatment failure and overall survival rates were 32.8% and 45.7%, respectively. The adverse prognostic factors for freedom from treatment failure were age >50 years (p < 0.001), B symptoms (p < 0.001), extranodal disease (p = 0.012), and less than a CR to the last chemotherapy regimen (p = 0.001). The adverse prognostic factors for overall survival were male gender (p = 0.034), age >50 years (p < 0.001), B symptoms (p = 0.002), and less than a CR to the last chemotherapy regimen (p = 0.002). Favorable cohorts had a 10-year freedom from treatment failure rate of 51% and overall survival rate of 92%.

CONCLUSIONS

Salvage radiotherapy is effective for selected patients with Hodgkin's lymphoma after chemotherapy failure and should be considered for incorporation into salvage programs.

Optimization of a pharmacophore model for 5-HT4 agonists using CoMFA and receptor based alignment

Twenty two 5-HT4 agonists obtained from our laboratory and the recent literature were used to develop a CoMFA model to predict 5-HT4 agonist activity. Two models were produced and compared for predictivity, the first by alignments based on atom overlapping (model A) and the second by adding agonist binding site interacting points of the 5-HT4 receptor (model B). Comparison of the two models showed that the q2 value for model A was 0.564 vs. 0.582 for model B. Model B indicated that the predictive power model stems from far lower steric contributions, 0.270 compared to model A's 0.502. The dominant defining features were the electrostatic contributions for model B, 0.664 up from 0.477 in model A. The contributions from the LogP factor were minimal, 0.085 in both models. The synthesized compounds showed agonist activity at mumol level.

Nipple aspiration and ductal lavage in women with a germline BRCA1 or BRCA2 mutation

Introduction

The aim of this study was to collect serial samples of nipple aspirate (NA) and ductal lavage (DL) fluid from women with germline BRCA1/2 mutations in order to create a biorepository for use in identifying biomarkers of breast cancer risk.

Methods

Between March 2003 and February 2005, 52 women with germline BRCA1 or BRCA2 mutations (median age 43 years, range 27 to 65 years) were scheduled for six-monthly NA, DL and venesection. DL was attempted for all NA fluid-yielding (FY) and any non-FY ducts that could be located at each visit.

Results

Twenty-seven (52%) women were postmenopausal, predominantly (19/27) from risk reducing bilateral salpingo-oophorectomy (BSO). FY ducts were identified in 60% of all women, 76% of premenopausal women versus 44% of postmenopausal (P = 0.026). Eighty-five percent of women had successful DL. Success was most likely in women with FY ducts (FY 94% versus non-FY 71% (P = 0.049). DL samples were more likely to be cellular if collected from FY ducts (FY 68% versus non-FY 43%; P = 0.037). Total cell counts were associated with FY status (FY median cell count 30,996, range 0 to >1,000,000 versus non-FY median cell count 0, range 0 to 173,577; P = 0.002). Four women (8%) had ducts with severe atypia with or without additional ducts with mild epithelial atypia; seven others had ducts with mild atypia alone (11/52 (21%) in total). Median total cell count was greater from ducts with atypia (105,870, range 1920 to >1,000,000) than those with no atypia (174, 0 to >1,000,000; P ≤ 0.001).

Conclusion

It is feasible to collect serial NA and DL samples from women at high genetic risk of breast cancer, and we are creating a unique, prospective collection of ductal samples that have the potential to be used for discovery of biomarkers of breast cancer risk and evaluate the ongoing effects of risk reducing BSO. DL cellular atypia was not predictive of a current breast cancer and longer follow up is needed to determine whether atypia is an additional marker of future breast cancer risk in this population already at high genetic risk of breast cancer.