Jump to content

Portenoy et al. (2012): Nabiximols for Opioid-Treated Cancer Patients With Poorly-Controlled Chronic Pain: A Randomized, Placebo-Controlled, Graded-Dose Trial

From CAMIH
Revision as of 08:33, 4 November 2024 by JDoerfler (talk | contribs)


Reference ↗
Title Nabiximols for Opioid-Treated Cancer Patients With Poorly-Controlled Chronic Pain: A Randomized, Placebo-Controlled, Graded-Dose Trial
Topic Cannabinoids
Author Portenoy, K, Ganae-Motan, ED, Allende, S, Yanagihara, R, Shaiova, L, Weinstein, S, McQuade, R, Wright, S, Fallon, MT
Year 2012
Journal The Journal of Pain
DOI https://doi.org/10.1016/j.jpain.2012.01.003

Study Note

Brief summary

In this study, the effect of nabiximol, a cannabis-containing oral spray, on the personal perception of pain in patients with various advanced cancers and moderate to severe tumor pain was investigated as a function of dose. The study compared four different arms, namely three different nabiximols arms (low dose, medium dose, high dose) and a placebo arm. With regard to the primary endpoint, namely the number of patients in whom treatment with nabiximols led to a significant improvement in pain perception (≥30%), there were no significant differences between the arms. However, it was found that patients with the low dose in particular, but in some cases also with the medium dose, responded better overall to the treatment compared to the placebo arm and reported a significantly greater improvement in pain and sleep disturbances on average over the course of the study. In addition, patients with the low dose of nabiximols required less opioids depending on the pain compared to the placebo arm.The large international sample was a positive aspect of this study, but there are also some points of criticism. In particular, the differences in treatment adherence between the arms, the lack of clarity as to whether the arms were comparable at the start of the study and the high drop-out rate during the course of the study should be mentioned. For this reason, the results of this study can only be interpreted with caution.


In dieser Studie wurde in Abhängigkeit der Dosis die Wirkung von Nabiximol, einem cannabishaltigen Mundspray, hinsichtlich der persönlichen Wahrnehmung von Schmerzen bei Patienten mit verschiedenen, vorangeschrittenen Krebserkrankungen und mittleren bis schweren Tumorschmerzen untersucht. In der Studie wurden vier verschiedene Gruppen verglichen, nämlich drei verschiedene Nabiximol-Arme (niedrige Dosis, mittlere Dosis, hohe Dosis) und eine Placebogruppe. Hinsichtlich des primären Endpunkts, nämlich der Anzahl an Patienten, bei denen die Behandlung mit Nabiximol zu einer deutlichen Verbesserung der Schmerzwahrnehmung (≥30%) geführt hat, zeigten sich keine bedeutsamen Unterschiede zwischen den Gruppen. Es wurde jedoch gefunden, dass vor allem Patienten mit der niedrigen Dosis, teilweise aber auch mit der mittleren Dosis im Vergleich zur Placebogruppe insgesamt besser auf die Behandlung ansprachen und im Mittel eine bedeutsam stärkere Verbesserung der Schmerzen und der Schlafstörungen im Verlauf der Studie berichteten. Zudem benötigen Patienten mit der niedrigen Nabiximoldosis weniger Opiode in Abhängigkeit der Schmerzen im Vergleich zur Placebogruppe. Positiv an dieser Studie war die große internationale Stichprobe, es lassen sich jedoch auch einige Kritikpunkte nennen. Dabei sind vor allem die Unterschiede in der Therapietreue zwischen den Armen, die Unklarkeit, ob die Gruppen zum Beginn der Studie vergleichbar waren zu nennen und die hohe Ausfallrate im Verlauf der Studie zu nennen. Deswegen lassen sich die Ergebnisse dieser Studie nur mit Vorsicht interpretieren.

Study Design

Prospective / Retrospective Prospective: forward-looking, examples include clinical trials, cohort studies, and long-term observational studies;</br>Retrospective: backward-looking, relying on existing data, examples include case-control studies and retrospective cohort studies Prospective
Monocentric / Multicentric Monocentric: conducted in one center/ hospital; </br>Multicentric: conducted in multiple centers/ hospitals Multicentric
Blinding No: Open, all parties are aware of group assignments;</br>Single: one party is unaware of group assignments (generally participants);</br>Double: two parties are unaware of group assignments (generally the participants and the researchers); </br>Triple: concealing group assignment from additional parties Double
Is randomized Yes
Cross-over Participants alternate between different treatment groups or conditions over a specified period, allowing each participant to serve as their own control No
Number of arms 4

Study characteristics

Inclusion criteria Adult patients with active cancer and chronic pain (moderate or severe despite a stable opioid regimen that could not be made more effective by further opioid dose titration); stable, average pain: NRS: ≥4≤ 8 (no change in 3 days > 2 points)
Exclusion criteria Patients receiving long-term methadone therapy for pain; major psychiatric or cardiovascular disorder; epilepsy; significant renal or hepatic impairment; pregnant, lactating or not using adequate contraception; patients, who had received or who were due to receive therapies expected to change the pain (such as radiotherapy, or chemotherapy or hormonal therapy); marijuana use, cannabinoid-based medications or rimonabant within 30 days of study entry, and unwilling to abstain for the duration of the study
N randomized 360
Analysis PP: Per Protocol analysis, i.e. only participants included who adhered to the study protocol.</br>ITT: Intention-to-treat analysis, i.e. all randomized participants included regardless of any drop-outs or changes in assignment.</br>mITT: modified Intention-to-treat analysis can refer to analyses in which participants with missing outcome data are excluded or it can refer to analyses in which only participants who received at least one treatment dose are included. In this case, participants dropped out of the study prematurely for reasons unrelated to the treatment. ITT Analysis
Specifications on analyses Missing data for the efficacy endpoints were imputed using the last observation carry forward (LOCF) method.

The proportions of responders were compared between the treatments using logistic regression, with region (North America/Rest of the World) and treatment used as factors.

The cumulative response to treatment was shown by plotting cumulative response rates against increasing thresholds for response, ie, percentage changes from baseline in the mean 11-point NRS pain score that defined a response. The cumulative response curves for each of the active treatment groups were compared with placebo using pairwise Wilcoxon rank-sum tests. The Hodges-Lehmann estimates and 95% CI for the median also were performed.

The analysis of all the secondary efficacy assessments was considered supportive and no formal adjustments for multiple comparisons were made. The change in mean pain NRS scores, BPI-SF, sleep disruption NRS, PAC-QoL questionnaire, and MADRS were all analyzed using analysis of covariance (ANCOVA), with the baseline value as a covariate and region and treatment group as factors. An analysis also was performed on the mean pain NRS scores to assess the time course of the treatment effect using repeated measure analysis. Additionally, the difference in time required to establish baseline was investigated as a possible moderator of treatment effect by using the number of days until the patient became eligible for randomization and total number of days in the baseline period as covariates in the analysis of change in the mean daily NRS score for average pain.

Countries of data collection Europe, South Africa, North America, Latin America
LoE Level of evidence Level 2 Oxford 2011
Outcome timeline Data collection times T1: baseline (3 days)

T2: day 21

T3: day 35 (end of intervention)

T4: 14 days after treatment

Characteristics of participants

Setting Refers to cancer therapy setting.</br>- Curative therapy: aims to completely eradicate a disease and achieve a full recovery; </br>- Neo-adjuvant therapy: form of curative therapy, given before the primary treatment for cancer (usually surgery); </br>- Adjuvant therapy: form of curative therapy, given after the primary treatment for cancer (usually surgery); </br>- Palliative therapy: focuses on providing relief from symptoms and improving the quality of life for patients, without necessarily targeting the underlying disease; </br>- Active surveillance: involves close monitoring of disease progression without any intervention (typically used for prostate cancer);</br>- No therapy setting: Patients who completed therapy/are currently not in cancer treatment, cancer survivors. Curative
Types of cancer "Other Cancers" means that only a subpopulation was specified, but further unspecified cancer types were included Breast Cancer, Gastrointestinal Cancers, Lung Cancer, Prostate Cancer, Other Cancers
Cancer stages Early Stage: generally refers to cancer that is localized to the area where it started, mostly stages I and II;</br>Advanced Stage: cancer that has spread beyond its original site, mostly stages III and IV, with stage IV indicating distant metastasis Advanced Stage
Specifications on cancer stages Mean (SD) duration = 3.6 (4.8) years
Comorbidities Chronic, therapy-resistant tumor pain (treated with opioids)
Current cancer therapies No therapy
Specifications on cancer therapies NA
Previous cancer therapies NI
Gender Mixed
Gender specifications Female n (%): 174 (48.3)

Male n (%): 186 (51.7)

Age groups Adults (18+)
Age groups specification Mean (SD) age = 58 (12.2) years

Range = 20-93 years

Arms

Arm type Active control: group receives active treatment; </br>Passive control: for example treatment as usual, waiting control, no treatment Intervention
Number of participants (arm) N randomized 91
Drop-out Number of participants who left the study for any reason or did not provide information on every data collection date 20
Drop-out reasons Side effects (n=5); consent withdrawn (n=1); progression of the disease (n=7); other reasons (n=3)
Intervention Nabiximol
Dosage and regime Nabiximol via oral spray (self-applied by patient, one spray 2.7 mg THC and 2.5 mg CBD)

Week 1: dose finding; week 2-5: stable dose

Maximal number of sprays: 1-4 (low dose)

One-time application No
Duration in days For long-term interventions, the number of days is an estimation.</br>A value of -999 indicates that the exact duration cannot be extracted from the study due to ambiguous or incomplete information. See Outcome timeline or Dosage and regime for further information. 35
Side effects / Interactions Cognitive functions: negative effect of nabiximols (no values given); nausea and vomiting; dizziness; drowsiness; disorientation; anorexia, constipation; dry mouth; anemia; diarrhea; dysgeusia headache; asthenia hallucinations; reduced appetite; fatigue; pain; insomnia; stomatitis; weight loss
Arm type Active control: group receives active treatment; </br>Passive control: for example treatment as usual, waiting control, no treatment Intervention
Number of participants (arm) N randomized 88
Drop-out Number of participants who left the study for any reason or did not provide information on every data collection date 21
Drop-out reasons Side effects (n=6); consent withdrawn (n=5); progression of the disease (n=7); other reasons (n=3)
Intervention Nabiximol
Dosage and regime Nabiximol via oral spray (self-applied by patient, one spray 2.7 mg THC and 2.5 mg CBD)

Week 1: dose finding; week 2-5: stable dose

Maximal number of sprays: 6-10 (medium dose)

One-time application No
Duration in days For long-term interventions, the number of days is an estimation.</br>A value of -999 indicates that the exact duration cannot be extracted from the study due to ambiguous or incomplete information. See Outcome timeline or Dosage and regime for further information. 35
Side effects / Interactions Cognitive functions: negative effect of nabiximols (no values given); nausea and vomiting; dizziness; drowsiness; disorientation; anorexia, constipation; dry mouth; anemia; diarrhea; dysgeusia headache; asthenia hallucinations; reduced appetite; fatigue; pain; insomnia; stomatitis; weight loss
Arm type Active control: group receives active treatment; </br>Passive control: for example treatment as usual, waiting control, no treatment Intervention
Number of participants (arm) N randomized 90
Drop-out Number of participants who left the study for any reason or did not provide information on every data collection date 31
Drop-out reasons Side effects (n=20); consent withdrawn (n=4); progression of the disease (n=7)
Intervention Nabiximol
Dosage and regime Nabiximol via oral spray (self-applied by patient, one spray 2.7 mg THC and 2.5 mg CBD)

Week 1: dose finding; week 2-5: stable dose

Maximal number of sprays: 11-16 (high dose)

One-time application No
Duration in days For long-term interventions, the number of days is an estimation.</br>A value of -999 indicates that the exact duration cannot be extracted from the study due to ambiguous or incomplete information. See Outcome timeline or Dosage and regime for further information. 35
Side effects / Interactions Cognitive functions: negative effect of nabiximols (no values given); nausea and vomiting; dizziness; drowsiness; disorientation; anorexia, constipation; dry mouth; anemia; diarrhea; dysgeusia headache; asthenia hallucinations; reduced appetite; fatigue; pain; insomnia; stomatitis weight loss
Arm type Active control: group receives active treatment; </br>Passive control: for example treatment as usual, waiting control, no treatment Placebo
Number of participants (arm) N randomized 91
Drop-out Number of participants who left the study for any reason or did not provide information on every data collection date 25
Drop-out reasons Side effects (n=9); consent withdrawn (n=6); progression of the disease (n=7): no effect (n=1); other reasons (n=1); no follow-up (n=1)
Intervention Placebo
Dosage and regime Placebo via oral spray (self-applied by patient)

Week 1: dose finding; week 2-5: stable dose

Maximal number of sprays: variable (1-4, 6-10, 11-16)

One-time application No
Duration in days For long-term interventions, the number of days is an estimation.</br>A value of -999 indicates that the exact duration cannot be extracted from the study due to ambiguous or incomplete information. See Outcome timeline or Dosage and regime for further information. 35
Side effects / Interactions NI

Outcomes

Pain

Outcome type As specificed by the authors Primary
Outcome specification Number of responders (≥ 30% pain reduction Numeric Rating Scale for average pain during the last 3 days of week 5 compared with the mean during the 3-day baseline period)
Type of measurement NRS (Numeric Rating Scale)
Results during intervention - Results during intervention means that the time of data collection is during or shortly after the period of the intervention (e.g. on the last day or a few days after). The results therefore still relate to the direct effects of the intervention.</br>- Results after intervention means there is a longer break between the time of data collection and the end of the intervention, e.g. more than a week. The results relate more to long-term effects.</br>- If a categorization in Results during vs. after intervention is not possible (e.g. survival data), the results are summarized under Results after intervention under the headline "Overall". Baseline to 5 weeks: no group differences; OR in each case
  • Nabiximol (1-4 sprays) + nabiximol (6-10 sprays) + nabiximol (11-16 sprays) vs. placebo: p=0.59
  • Nabiximol (1-4 sprays) vs. placebo: 1.37; p=0.33
  • Nabiximol (6-10 sprays) vs. placebo: 1.19, p=0.61
  • Nabiximol (11-16 sprays) vs. placebo: 0.9, p=0.76
Results after intervention - Results during intervention means that the time of data collection is during or shortly after the period of the intervention (e.g. on the last day or a few days after). The results therefore still relate to the direct effects of the intervention.</br>- Results after intervention means there is a longer break between the time of data collection and the end of the intervention, e.g. more than a week. The results relate more to long-term effects.</br>- If a categorization in Results during vs. after intervention is not possible (e.g. survival data), the results are summarized under Results after intervention under the headline "Overall". NA
Risk of Bias Assessment: Cochrane RoB tool 2.0
Bias arising from the randomization process some concerns
Bias due to deviation from intended intervention (assignment to intervention) low risk
Bias due to deviation from intended intervention (adhering to intervention) NA
Bias due to missing outcome data low risk
Bias in measurement of the outcome some concerns
Bias in selection of the reported result some concerns
Other sources of bias NA
Overall RoB judgment some concerns

Pain

Outcome type As specificed by the authors Secondary
Outcome specification Number per improvement level (10%, 20% etc.-100%)
Type of measurement Observation
Results during intervention - Results during intervention means that the time of data collection is during or shortly after the period of the intervention (e.g. on the last day or a few days after). The results therefore still relate to the direct effects of the intervention.</br>- Results after intervention means there is a longer break between the time of data collection and the end of the intervention, e.g. more than a week. The results relate more to long-term effects.</br>- If a categorization in Results during vs. after intervention is not possible (e.g. survival data), the results are summarized under Results after intervention under the headline "Overall". Over the course of the sudy significant difference between intervention combined arms and placebo: full spectrum 0-100% responders (OR in each case):
  • Nabiximol (1-4 sprays) + nabiximol (6-10 sprays) + nabiximol (11-16 sprays) vs. placebo: p=0.035
  • Nabiximol (1-4 sprays) vs. placebo: p=0.008
  • Nabiximol (6-10 sprays) vs. placebo: p=0.038
  • Nabiximol (11-16 sprays) vs. placebo: p=0.68
Results after intervention - Results during intervention means that the time of data collection is during or shortly after the period of the intervention (e.g. on the last day or a few days after). The results therefore still relate to the direct effects of the intervention.</br>- Results after intervention means there is a longer break between the time of data collection and the end of the intervention, e.g. more than a week. The results relate more to long-term effects.</br>- If a categorization in Results during vs. after intervention is not possible (e.g. survival data), the results are summarized under Results after intervention under the headline "Overall". NA
Risk of Bias Assessment: Cochrane RoB tool 2.0
Bias arising from the randomization process some concerns
Bias due to deviation from intended intervention (assignment to intervention) low risk
Bias due to deviation from intended intervention (adhering to intervention) NA
Bias due to missing outcome data low risk
Bias in measurement of the outcome some concerns
Bias in selection of the reported result some concerns
Other sources of bias NA
Overall RoB judgment some concerns

Pain

Outcome type As specificed by the authors Secondary
Outcome specification Change in NRS value for moderate pain
Type of measurement NRS (Numeric Rating Scale)
Results during intervention - Results during intervention means that the time of data collection is during or shortly after the period of the intervention (e.g. on the last day or a few days after). The results therefore still relate to the direct effects of the intervention.</br>- Results after intervention means there is a longer break between the time of data collection and the end of the intervention, e.g. more than a week. The results relate more to long-term effects.</br>- If a categorization in Results during vs. after intervention is not possible (e.g. survival data), the results are summarized under Results after intervention under the headline "Overall". Baseline to 5 weeks:

No significant group differences between intervention groups combined and placebo:

  • Nabiximol (1-4 sprays) + nabiximol (6-10 sprays) + nabiximol (11-16 sprays) vs. placebo: p=0.072


Mean:

  • Nabiximol (1-4 sprays): baseline = 5.8, day 35 = 4.3
  • Nabiximol (6-10 sprays): baseline = 5.8, day 35 = 4.7
  • Nabiximol (11-16 sprays): NI
  • Placebo: baseline = 5.7, day 35 = 4.9


Significant difference between nabiximol (1-4 sprays) and placebo: mean difference (95% CI)

  • Nabiximol (1-4 sprays) vs. placebo = -0.75 (-1.28, 0.22), p=0.006


Otherwise no differences:

  • Nabiximol (6-10 sprays) vs. placebo = -0.36 (-0.89, 0.18), p=0.19
  • Nabiximol (11-16 sprays) vs. placebo = -0.09 (-0.62, 0.44), p=0.75
Results after intervention - Results during intervention means that the time of data collection is during or shortly after the period of the intervention (e.g. on the last day or a few days after). The results therefore still relate to the direct effects of the intervention.</br>- Results after intervention means there is a longer break between the time of data collection and the end of the intervention, e.g. more than a week. The results relate more to long-term effects.</br>- If a categorization in Results during vs. after intervention is not possible (e.g. survival data), the results are summarized under Results after intervention under the headline "Overall". NA
Risk of Bias Assessment: Cochrane RoB tool 2.0
Bias arising from the randomization process some concerns
Bias due to deviation from intended intervention (assignment to intervention) low risk
Bias due to deviation from intended intervention (adhering to intervention) NA
Bias due to missing outcome data low risk
Bias in measurement of the outcome some concerns
Bias in selection of the reported result some concerns
Other sources of bias NA
Overall RoB judgment some concerns

Pain

Outcome type As specificed by the authors Secondary
Outcome specification Change in NRS value for the worst pain
Type of measurement NRS (Numeric Rating Scale)
Results during intervention - Results during intervention means that the time of data collection is during or shortly after the period of the intervention (e.g. on the last day or a few days after). The results therefore still relate to the direct effects of the intervention.</br>- Results after intervention means there is a longer break between the time of data collection and the end of the intervention, e.g. more than a week. The results relate more to long-term effects.</br>- If a categorization in Results during vs. after intervention is not possible (e.g. survival data), the results are summarized under Results after intervention under the headline "Overall". Baseline to 5 weeks:

Significant difference between nabiximol (1-4 sprays) and placebo: mean difference (95% CI)

  • Nabiximol (1-4 sprays) vs. placebo =- 0.73 (-1.30, -0.17), p=0.011


Otherwise no significant differences:

  • Nabiximol (6-10 sprays) vs. placebo = -0.24 (-0.8, 0.3), p=0.4
  • Nabiximol (11-16 sprays) vs. placebo = -0.6 (-0.6, 0.5), p=0.83
Results after intervention - Results during intervention means that the time of data collection is during or shortly after the period of the intervention (e.g. on the last day or a few days after). The results therefore still relate to the direct effects of the intervention.</br>- Results after intervention means there is a longer break between the time of data collection and the end of the intervention, e.g. more than a week. The results relate more to long-term effects.</br>- If a categorization in Results during vs. after intervention is not possible (e.g. survival data), the results are summarized under Results after intervention under the headline "Overall". NA
Risk of Bias Assessment: Cochrane RoB tool 2.0
Bias arising from the randomization process some concerns
Bias due to deviation from intended intervention (assignment to intervention) low risk
Bias due to deviation from intended intervention (adhering to intervention) NA
Bias due to missing outcome data low risk
Bias in measurement of the outcome some concerns
Bias in selection of the reported result some concerns
Other sources of bias NA
Overall RoB judgment some concerns

Sleep

Outcome type As specificed by the authors Others
Outcome specification Extent of sleep disturbance
Type of measurement NRS (Numeric Rating Scale)
Results during intervention - Results during intervention means that the time of data collection is during or shortly after the period of the intervention (e.g. on the last day or a few days after). The results therefore still relate to the direct effects of the intervention.</br>- Results after intervention means there is a longer break between the time of data collection and the end of the intervention, e.g. more than a week. The results relate more to long-term effects.</br>- If a categorization in Results during vs. after intervention is not possible (e.g. survival data), the results are summarized under Results after intervention under the headline "Overall". Significant difference between nabiximol (1-4 sprays) and placebo: mean difference (95% CI)
  • Nabiximol (1-4 sprays) vs. placebo = -0.88 (-1.45, -0.31), p = 0.003


Otherwise no differences:

  • Nabiximol (6-10 sprays)/nabiximol (11-16 sprays) alone vs. placebo: not significant


Combining low and high dose group:

  • Significant difference vs. placebo in favor of nabiximols (p = .016)
Results after intervention - Results during intervention means that the time of data collection is during or shortly after the period of the intervention (e.g. on the last day or a few days after). The results therefore still relate to the direct effects of the intervention.</br>- Results after intervention means there is a longer break between the time of data collection and the end of the intervention, e.g. more than a week. The results relate more to long-term effects.</br>- If a categorization in Results during vs. after intervention is not possible (e.g. survival data), the results are summarized under Results after intervention under the headline "Overall". NA
Risk of Bias Assessment: Cochrane RoB tool 2.0
Bias arising from the randomization process some concerns
Bias due to deviation from intended intervention (assignment to intervention) low risk
Bias due to deviation from intended intervention (adhering to intervention) NA
Bias due to missing outcome data low risk
Bias in measurement of the outcome some concerns
Bias in selection of the reported result some concerns
Other sources of bias NA
Overall RoB judgment some concerns

Pain

Outcome type As specificed by the authors NI
Outcome specification Opiod consumption: score from change in self-assessed pain in relation to opiod consumption in morphine-equivalent milligrams)
Type of measurement Observation
Results during intervention - Results during intervention means that the time of data collection is during or shortly after the period of the intervention (e.g. on the last day or a few days after). The results therefore still relate to the direct effects of the intervention.</br>- Results after intervention means there is a longer break between the time of data collection and the end of the intervention, e.g. more than a week. The results relate more to long-term effects.</br>- If a categorization in Results during vs. after intervention is not possible (e.g. survival data), the results are summarized under Results after intervention under the headline "Overall". No significant group differences between intervention groups combined and placebo: OR (95% CI)
  • Nabiximol (1-4 sprays) + nabiximol (6-10 sprays) + nabiximol (11-16 sprays) vs. placebo =1.54 (0.95, 2.50), p = 0.077
  • Significant difference for nabiximol (1-4 sprays) vs. placebo = 1.87, p=0.038


Otherwise no differences:

  • Nabiximol (6-10 sprays)/nabiximol (11-16 sprays) vs. placebo: not significant
Results after intervention - Results during intervention means that the time of data collection is during or shortly after the period of the intervention (e.g. on the last day or a few days after). The results therefore still relate to the direct effects of the intervention.</br>- Results after intervention means there is a longer break between the time of data collection and the end of the intervention, e.g. more than a week. The results relate more to long-term effects.</br>- If a categorization in Results during vs. after intervention is not possible (e.g. survival data), the results are summarized under Results after intervention under the headline "Overall". NA
Risk of Bias Assessment: Cochrane RoB tool 2.0
Bias arising from the randomization process some concerns
Bias due to deviation from intended intervention (assignment to intervention) low risk
Bias due to deviation from intended intervention (adhering to intervention) NA
Bias due to missing outcome data low risk
Bias in measurement of the outcome some concerns
Bias in selection of the reported result some concerns
Other sources of bias NA
Overall RoB judgment some concerns

Pain

Outcome type As specificed by the authors Others
Outcome specification NA
Type of measurement BPI-SF (Brief Pain Inventory - Short Form)
Results during intervention - Results during intervention means that the time of data collection is during or shortly after the period of the intervention (e.g. on the last day or a few days after). The results therefore still relate to the direct effects of the intervention.</br>- Results after intervention means there is a longer break between the time of data collection and the end of the intervention, e.g. more than a week. The results relate more to long-term effects.</br>- If a categorization in Results during vs. after intervention is not possible (e.g. survival data), the results are summarized under Results after intervention under the headline "Overall". After 5 weeks: No significant differences.
Results after intervention - Results during intervention means that the time of data collection is during or shortly after the period of the intervention (e.g. on the last day or a few days after). The results therefore still relate to the direct effects of the intervention.</br>- Results after intervention means there is a longer break between the time of data collection and the end of the intervention, e.g. more than a week. The results relate more to long-term effects.</br>- If a categorization in Results during vs. after intervention is not possible (e.g. survival data), the results are summarized under Results after intervention under the headline "Overall". NA
Risk of Bias Assessment: Cochrane RoB tool 2.0
Bias arising from the randomization process some concerns
Bias due to deviation from intended intervention (assignment to intervention) low risk
Bias due to deviation from intended intervention (adhering to intervention) NA
Bias due to missing outcome data low risk
Bias in measurement of the outcome some concerns
Bias in selection of the reported result some concerns
Other sources of bias NA
Overall RoB judgment some concerns

Quality of life

Outcome type As specificed by the authors Others
Outcome specification NA
Type of measurement EORTC QLQ (European Organisation for Research and Treatment of Cancer Core/ Quality of Life questionnaire), MADRS (Montgomery-Asberg Depression Rating Scale), PAC-QoL (Patient Assessment of Constipation - Quality of Life)
Results during intervention - Results during intervention means that the time of data collection is during or shortly after the period of the intervention (e.g. on the last day or a few days after). The results therefore still relate to the direct effects of the intervention.</br>- Results after intervention means there is a longer break between the time of data collection and the end of the intervention, e.g. more than a week. The results relate more to long-term effects.</br>- If a categorization in Results during vs. after intervention is not possible (e.g. survival data), the results are summarized under Results after intervention under the headline "Overall". After 5 weeks: Small effect of nabiximol on EORTC-QCQ-C30 (no values given), otherwise no significant differences for questionnaires.
Results after intervention - Results during intervention means that the time of data collection is during or shortly after the period of the intervention (e.g. on the last day or a few days after). The results therefore still relate to the direct effects of the intervention.</br>- Results after intervention means there is a longer break between the time of data collection and the end of the intervention, e.g. more than a week. The results relate more to long-term effects.</br>- If a categorization in Results during vs. after intervention is not possible (e.g. survival data), the results are summarized under Results after intervention under the headline "Overall". NA
Risk of Bias Assessment: Cochrane RoB tool 2.0
Bias arising from the randomization process some concerns
Bias due to deviation from intended intervention (assignment to intervention) low risk
Bias due to deviation from intended intervention (adhering to intervention) NA
Bias due to missing outcome data low risk
Bias in measurement of the outcome high risk
Bias in selection of the reported result some concerns
Other sources of bias NA
Overall RoB judgment high risk

Funding and Conflicts of Interest

Funding Supported in part by the Huntsman Cancer Foundation (S.W.). GW Pharmaceuticals produces nabiximols, which is licensed in Canada as an adjunctive analgesic treatment in adult patients with advanced cancer.

This study was funded by GW Pharmaceuticals and Otsuka.

Conflicts of Interest NI

Further points for assessing the study

Sample

Power analysis performed Yes
- Sample size corresponds to power analysis Yes
- Reasons for insufficient sample size based on power analysis NA
If no power analysis performed: at least moderate sample size (n >= 30 per arm) NA
Ethnicity mentioned Yes

Alternative Explanation

Other explanations for an effect besides the investigated intervention Yes
- Possibility of attention effects NA
- Possibility of placebo effects NA
- Other reasons Compliance different in arms 94.5%, 85.1%, 62.2%, placebo NI

Post-hoc analyses show confounding variables that lead to increased deaths in intervention arms: High level of white blood cells, low level of calcium, hemoglobin and lymphocytes --> doubts about comparability of the arms

In the analyses of subjective perception of pain, no control of changes in opiod consumption

Statistics

Correct use of parametric and non-parametric tests Testing for normal distribution only necessary if parametric tests are used, NI: use of parametric tests without report of normal distribution testing NI
Correction for multiple testing Yes
Measurement of compliance Yes
Consistent reporting in numbers (figures, flowchart, abstract, results) Yes
Comprehensive and coherent reporting No
Cross-over No
- Sufficient washout period NA
- Tested for carry-over effects NA
- Tested for sequence effects NA

Interpretation of results

Effect sizes reported (clinical vs. statistical significance) No
Side effects systematically recorded No
Side effects considered in result interpretation NI
Ethics votum Yes


Additional Notes

PRO:

  • Ethical approval
  • Intent-to-treat analysis
  • Power analysis


CONTRA:

  • Differences in treatment adherence
  • Some descriptive differences at baseline without p-values provided (e.g., pain duration)
  • Post-hoc analyses reveal confounding variables associated with higher mortality rates in intervention arms: high white blood cell count, low calcium, hemoglobin, and lymphocyte levels, raising doubts about group comparability.
  • In analyses of subjective pain perception, changes in opioid consumption were not controlled for.
  • Mostly one-dimensional pain parameters were considered.
  • Results in the text are reported unclearly, with some values missing or not precisely specified.
  • No information on cancer stage.
  • Poor reporting quality.
  • Correction for multiple comparison only for primary endpoints