Mannitol, capsule containing powder for oral inhalation, 40 mg (for use in inhaler device), Bronchitol® - March 2011
Page last updated: 15 July 2011
Public Summary Document
Product: Mannitol, capsule containing powder for
                           oral inhalation, 40 mg (for use in inhaler device),
                           Bronchitol®
Sponsor: Pharmaxis Ltd
Date of PBAC Consideration: March 2011
1. Purpose of Application
                           The submission sought a Section 100 (Highly Specialised Drug) PBS
                           listing for the treatment of cystic fibrosis (CF) in both
                           paediatric (six years and above) and adult populations as either
                           add on therapy to dornase alfa or in patients intolerant to, or
                           inadequately responsive to dornase alfa.
                           Highly Specialised Drugs are medicines for the treatment of chronic
                           conditions, which, because of their clinical use or other special
                           features, are restricted to supply to public and private hospitals
                           having access to appropriate specialist facilities.
2. Background
                           This drug had not previously been considered by the PBAC.
3. Registration Status
                           Mannitol powder for inhalation (Bronchitol®) was TGA
                           registered on 11 March 2011 for the treatment of cystic fibrosis
                           (CF) in both paediatric and adult populations six years and above
                           as either an add-on therapy to dornase alfa or in patients
                           intolerant to, or inadequately responsive to dornase alfa.
4. Listing Requested and PBAC’s View
                           The submission proposed two listings, option A and B.
Option A
Section 100 (Highly Specialised Drugs)
                           Bronchitol is indicated for the treatment of cystic fibrosis (CF)
                           in both paediatric and adult populations six years and above as
                           either add-on therapy to dornase alpha or in patients intolerant of
                           or inadequately responsive to dornase alfa.
Private Hospital Authority Required
                           Use by cystic fibrosis patients who satisfy all of the following
                           criteria:
                           (1) are 6 years of age or older;
                           (2) have a FEV1 greater than 30% predicted for age, gender and
                           height
                           (3) are on dornase alfa or are intolerant or inadequately
                           responsive to dornase alfa
                           (4) have evidence of chronic suppurative lung disease (cough and
                           sputum most days of the week, or greater than 3 respiratory tract
                           infections of more than 2 weeks' duration in any 12 months, or
                           objective evidence of obstructive airways disease);
Private hospital authority required
                           PATIENTS WHO ARE NOT CURRENTLY ON DORNASE ALPHA
                           Treatment of cystic fibrosis patients who;
                           
                        
- have previously trialled and not met subsidisation criteria for dornase alfa
- Are intolerant to dornase alfa
- Do not continue dornase alfa after clinical assessment
                           In order for patients to be eligible for participation in the HSD
                           program, the following conditions must be met:
                           (1) Patients must be assessed at cystic fibrosis clinics/centres
                           which are under the control of specialist respiratory physicians
                           with experience and expertise in the management of cystic fibrosis
                           and the prescribing of mannitol powder for inhalation therapy under
                           the HSD program is limited to such physicians. If attendance at
                           such units is not possible because of geographical isolation,
                           management (including prescribing) may be by specialist physician
                           or paediatrician in consultation with such a unit;
                           (2) The measurement of lung function is to be conducted by
                           independent (other than the treating doctor) experienced personnel
                           at established lung function testing laboratories, unless this is
                           not possible because of geographical isolation;
                           (3) Prior to mannitol powder for inhalation therapy, a baseline
                           measurement of FEV1 must be undertaken during a stable
                           period of the disease;
                           (4) Patients must be assessed for bronchial hyperresponsiveness as
                           per TGA approved PI Mannitol Tolerance Test. If the patient has a
                           positive hyperresponsiveness test they must not be prescribed
                           Mannitol powder for inhalation. Patients with negative tests may
                           commence mannitol powder for inhalation therapy.
                           (5) Initial therapy is limited to 4 weeks' treatment with
                           Bronchitol at 400 mg BD;
                           (6) At or towards the end of the initial 4 weeks' trial, patients
                           must be reassessed and a further FEV1 measurement be
                           undertaken (single test under conditions as above). Patients who
                           achieve a 10% or greater improvement in FEV1 (compared
                           to baseline established prior to mannitol for inhalation treatment)
                           are eligible for continued subsidy under the HSD program at a dose
                           of 400mg BD;
                           (7) Patients who fail to meet a 10% or greater improvement in
                           FEV1 after the initial 4 weeks' treatment at a dose of
                           400mg BD, may have 1 further trial in the next 12 months but not
                           before 3 months after the initial trial;
                           (8) Following an initial 6 months' therapy, a global assessment
                           must be undertaken involving the patient, the patient's family (in
                           the case of paediatric patients) and the treating physician(s) to
                           establish that all agree that mannitol powder for inhalation
                           treatment is continuing to produce worthwhile benefits. (Mannitol
                           powder for inhalation therapy should cease if there is not general
                           agreement of benefit as there is always the possibility of harm
                           from unnecessary use.) Further reassessments are to be undertaken
                           at six-monthly intervals;
                           (9) Other aspects of treatment, such as physiotherapy, must be
                           continued;
                           (10) Where there is documented evidence that a patient already
                           receiving mannitol powder for inhalation therapy would have met the
                           criteria for subsidy (i.e. satisfied the criteria for the 4 week
                           trial and achieved a 10% or greater improvement in FEV1)
                           then the patient is eligible to continue treatment under the HSD
                           program. Where such evidence is not available, patients will need
                           to satisfy the initiation and continuation criteria as for new
                           patients. (Four weeks is considered a suitable wash-out
                           period).
                           Note:
                           It is highly desirable that all patients be included in the
                           national cystic fibrosis patient data-base.
Private hospital authority required
                           TREATMENT OF CYSTIC FIBROSIS PATIENRS CURRENTLY TAKING DORNASE
                           ALFA
                           In order for patients to be eligible for participation in the HSD
                           program, the following conditions must be met:
                           (1) Patients must have been taking dornase alfa for at least 6
                           months;
                           (2) Following an initial 6 months' therapy of dornase alfa, a
                           global assessment must be undertaken involving the patient, the
                           patient's family (in the case of paediatric patients) and the
                           treating physician(s) to establish that all agree that greater
                           improvement in FEV1 could be achieved with the addition
                           of mannitol powder for inhalation. (Mannitol powder for inhalation
                           therapy should not be commenced if there is not general agreement
                           that greater FEV1 improvement could be attained or if
                           there is a possibility of harm from unnecessary use.) Further
                           reassessments are to be undertaken at six-monthly intervals;
                           (3) The measurement of lung function is to be conducted by
                           independent (other than the treating doctor) experienced personnel
                           at established lung function testing laboratories, unless this is
                           not possible because of geographical isolation;
                           (4) Prior to mannitol for inhalation therapy, a baseline
                           measurement of FEV1 must be undertaken during a stable period of
                           the disease;
                           (5) Patients must be assessed for bronchial hyperresponsiveness as
                           per TGA approved PI Mannitol Tolerance Test. If the patient is
                           hyperresponsive to mannitol they must not be prescribed Mannitol
                           powder for inhalation. Patients with negative tests may commence
                           mannitol powder for inhalation therapy.
                           (6) Initial therapy is limited to 4 weeks' treatment with
                           Bronchitol at 400mg BD;
                           (7) At or towards the end of the initial 4 weeks' trial, patients
                           must be reassessed and a further FEV1 measurement be
                           undertaken (single test under conditions as above). Patients who
                           achieve a 10% or greater improvement in FEV1 (compared to first
                           line dornase alfa therapy [established prior to mannitol for
                           inhalation treatment]) are eligible for continued subsidy under the
                           HSD program at a dose of 400mg BD;
                           (8) Patients who fail to meet a 10% or greater improvement in
                           FEV1 (compared to first line dornase alpha therapy
                           baseline after the initial 4 weeks' treatment at a dose of 400mg
                           BD, may have 1 further add on trial in the next 12 months but not
                           before 3 months after the initial trial;
                           (9) Other aspects of treatment, such as physiotherapy, must be
                           continued;
                           Note: It is highly desirable that all patients be included in the
                           national cystic fibrosis patient data-base.
Option B
                           Section 100 (Highly Specialised Drugs)
                           Bronchitol is indicated for the treatment of cystic fibrosis (CF)
                           in both paediatric and adult populations six years and above s
                           either add-on therapy to dornase alpha or in patients intolerant of
                           or inadequately responsive to dornase alfa.
                           
                        
Private Hospital Authority Required
                           Use by cystic fibrosis patients who satisfy all of the following
                           criteria:
                           (1) are 6 years of age or older;
                           (2) are on dornase alfa or are intolerant or inadequately
                           responsive to rhDNase
                           
                        
Private hospital authority required
                           PATIENTS WHO ARE NOT CURRENTLY ON DORNASE ALPHA
                           Treatment of cystic fibrosis patients who;
                           
                        
- have previously trialled and not met subsidisation criteria for Dornase alpha
- are intolerant to dornase alfa
- do not continue dornase alfa after clinical assessment
                           In order for patients to be eligible for participation in the HSD
                           program, the following conditions must be met:
                           (1) Patients must be assessed at cystic fibrosis clinics/centres
                           which are under the control of specialist respiratory physicians
                           with experience and expertise in the management of cystic fibrosis
                           and the prescribing of mannitol powder for inhalation therapy under
                           the HSD program is limited to such physicians. If attendance at
                           such units is not possible because of geographical isolation,
                           management (including prescribing) may be by specialist physician
                           or paediatrician in consultation with such a unit;
                           (2) The measurement of lung function is to be conducted by
                           independent (other than the treating doctor) experienced personnel
                           at established lung function testing laboratories, unless this is
                           not possible because of geographical isolation;
                           (3) Patients must be assessed for bronchial hyperresponsiveness as
                           per TGA approved PI Mannitol Tolerance Test. If the patient has a
                           positive hyperresponsiveness test they must not be prescribed
                           Mannitol powder for inhalation. Patients with negative tests may
                           commence mannitol powder for inhalation therapy.
                           (4) Following an initial 6 months' therapy, a global assessment
                           must be undertaken involving the patient, the patient's family (in
                           the case of paediatric patients) and the treating physician(s) to
                           establish that all agree that mannitol powder for inhalation
                           treatment is continuing to produce worthwhile benefits. (Mannitol
                           powder for inhalation therapy should cease if there is not general
                           agreement of benefit as there is always the possibility of harm
                           from unnecessary use.) Further reassessments are to be undertaken
                           at six-monthly intervals;
                           (5) Other aspects of treatment, such as physiotherapy, must be
                           continued.
                           Note:
                           It is highly desirable that all patients be included in the
                           national cystic fibrosis patient data-base.
Private hospital authority required
                           TREATMENT OF CYSTIC FIBROSIS PATIENTS CURRENTLY TAKING DORNASE
                           ALFA
                           In order for patients to be eligible for participation in the HSD
                           program, the following conditions must be met:
                           (1) Patients must have been taking dornase alfa for at least 6
                           months;
                           (2) Following an initial 6 months' therapy of dornase alfa , a
                           global assessment must be undertaken involving the patient, the
                           patient's family (in the case of paediatric patients) and the
                           treating physician(s) to establish that all agree that greater
                           improvement in FEV1 could be achieved with the addition
                           of mannitol powder for inhalation. (Mannitol powder for inhalation
                           therapy should not be commenced if there is not general agreement
                           that greater FEV1 improvement could be attained or if
                           there is a possibility of harm from unnecessary use.) Further
                           reassessments are to be undertaken at six-monthly intervals;
                           (3) The measurement of lung function is to be conducted by
                           independent (other than the treating doctor) experienced personnel
                           at established lung function testing laboratories, unless this is
                           not possible because of geographical isolation;
                           (4) Patients must be assessed for bronchial hyperresponsiveness as
                           per TGA approved PI Mannitol Tolerance Test. If the patient is
                           hyperresponsive to mannitol they must not be prescribed Mannitol
                           powder for inhalation. Patients with negative tests may commence
                           mannitol powder for inhalation therapy.
                           (5) Other aspects of treatment, such as physiotherapy, must be
                           continued.
                           Note: It is highly desirable that all patients be included in the
                           national cystic fibrosis patient data-base.
For PBAC’s view, see Recommendation and
                              Reasons.
5. Clinical Place for the Proposed Therapy
                           Cystic fibrosis (CF) is a common hereditary disease which affects
                           the entire body, causing progressive disability and often early
                           death. CF is caused by a mutation in the gene for the protein
                           cystic fibrosis transmembrane conductance regulator (CFTR). This
                           gene is required to regulate the components of sweat, digestive
                           juices, and mucus.
                           The aim of treatment of CF is to alleviate symptoms, improve
                           quality of life and to slow the decline in lung function. This is
                           achieved by improving airway clearance, by eradicating or
                           suppressing the growth of bacterial pathogens and attenuating
                           airway inflammation.
                           By mid childhood, most patients have increased airway secretions,
                           and enhancing mucus clearance is a major goal of therapy. Several
                           strategies have been proven to be effective, including
                           physiotherapy, local hydration with inhaled moisture, enzymes to
                           break down the inflammatory cell products, anti-inflammatory agents
                           and aggressive treatment of bacterial infections. In a proportion
                           of patients, mucolytic agents are prescribed. Currently dornase
                           alfa is the only mucolytic agent subsidised on the PBS for use in
                           CF.
                           The submission proposed that the place in therapy of mannitol
                           powder for inhalation is either as add on therapy to dornase alfa
                           or as an alternative therapy for patients 6 years of age or older
                           intolerant or inadequately responsive to dornase alfa.
6. Comparator
The submission presented two comparators for dry powder for inhalation (DPI) mannitol based on whether DPI mannitol is used as a monotherapy or add-on therapy:
- For patients who are intolerant or unresponsive to dornase alfa the submission nominated a comparison between DPI mannitol monotherapy vs. re-trial with dornase alfa.
                           This was not accepted by the PBAC.
- For patients who have an inadequate response to dornase alfa the submission nominated a comparison between dornase alfa plus DPI mannitol add-on therapy vs. dornase alfa alone.
For PBAC’s view, see Recommendation and
                              Reasons.
7. Clinical Trials
                           The submission presented one head-to-head cross-over trial of DPI
                           mannitol vs. dornase alfa vs. DPI mannitol and dornase alfa
                           combination in children with cystic fibrosis (CF-203, n=26)).
                           The submission also presented two trials of DPI mannitol vs. a
                           sub-therapeutic dose of mannitol as control (CF-301, n=295; CF-302,
                           n=305) and one trial of dornase alfa vs placebo (Fuchs et al
                           1994) in children and adults with cystic fibrosis.
                           For the comparison of DPI mannitol as add-on to dornase alfa vs
                           dornase alfa alone, trials CF-301/CF-302 included predefined
                           subgroup analyses of patients on concomitant use of dornase alfa;
                           ie those patients on dornase alfa at baseline continue to use
                           dornase alfa during the trial.
                           The table below details the published trials presented in the
                           submission:
| Trial ID/ First author | Protocol title/ Publication title | Publication citation | 
| DPI mannitol vs. dornase alfa vs. DPI mannitol/dornase alfa combination | ||
| CF-203, Minasian et al. | Comparison of inhaled mannitol, daily rhDNase and a combination of both in children with cystic fibrosis: A randomised trial. | Thorax, 2010, 65(1): 51-56 | 
| Dornase alfa vs. placebo | ||
| Fuchs | Effect of aerosolized recombinant human DNase on exacerbations of respiratory symptoms and on pulmonary function in patients with cystic fibrosis. The Pulmozyme Study Group. | The New England Journal of Medicine, 1994, 331(10): 637-42 | 
| Shak | Aerosolized recombinant human DNase I for the treatment of cystic fibrosis. | Chest 107(2 Suppl), 1995: 65s-70s | 
| Oster et al . | Effects of recombinant human DNase therapy on healthcare use and costs in patients with cystic fibrosis. | The Annals of Pharmacotherapy, 1995, 29(5): 459-64 | 
8. Results of Trials
Direct comparison (CF-203, n=26)
 Based on the key
                           outcomes (FEV1, protocol defined pulmonary exacerbation
                           (PDPE) events and quality of life(QOL)) reported in the
                           head-to-head cross-over trial of DPI mannitol vs. dornase alfa vs.
                           DPI mannitol/dornase alfa combination (CF-203) the PBAC noted that
                           there were no statistically significant differences in lung
                           function (as measured by FEV1 and FVC,
                           FEV1/FVC, FEF25-75, PEF), PDPE events or
                           respiratory quality of life scores between treatment groups.
                           The PBAC acknowledged that trial CF-203 was underpowered and the
                           larger trials of CF-301/CF-302, which had subgroups of patients on
                           either both treatments or mannitol monotherapy, did not show a
                           consistent trend of patients performing worse when the using
                           mannitol in combination with dornase alfa, the benefit of mannitol
                           as an add-on therapy remains uncertain.
DPI mannitol vs. control (sub-therapeutic mannitol) (CF-301/CF-302)
                           The main FEV1 results from the CF-301/CF-302 trials were
                           reported as either the mean change from baseline to Week 26 or as
                           the overall change from baseline averaged over the Week 6, 14 and
                           26 time points. The submission presented both sets of results and a
                           meta-analysis using the mean change in FEV1 from
                           baseline to Week 26. For consistency, the meta-analysis was
                           conducted during the evaluation using the overall change (Week
                           6-26) in FEV1 from baseline.
                           The PBAC noted that DPI mannitol was associated with statistically
                           significant short-term (26 week) improvements in lung function
                           (FEV1) compared to control in the total CF-301/CF-302
                           populations (approximately 2-4% absolute FEV1
                           improvement depending on measure).
                           The key spirometry outcomes reported in the dornase alfa
                           users/non-users subgroups of the DPI mannitol vs. control trials
                           (CF-301, CF-302) showed that DPI mannitol treatment was associated
                           with a statistically significant improvement in lung function
                           compared to control both in patients receiving concomitant dornase
                           alfa (overall FEV1 change 3.20%, p = 0.014) and in
                           patients not receiving concomitant dornase alfa (overall
                           FEV1 change 4.65%, p = 0.007).
                           The key clinical outcomes reported in the total populations of the
                           DPI mannitol vs. control trials (CF-301, CF-302) were mean
                           annualised rate of PDPE and PE events per patient.
                           The PBAC noted that there were no statistically significant
                           differences in exacerbation rates, use of rescue antibiotics or
                           hospitalisations between DPI mannitol and control in the
                           CF-301/CF-302 populations. There was also no statistically
                           significant difference in exacerbation rates between DPI mannitol
                           and control in patients using concomitant dornase alfa.
                           DPI mannitol treatment was associated with a statistically
                           significant decrease in protocol defined pulmonary exacerbation
                           (PDPE) rates compared to control in patients that were not using
                           concomitant dornase alfa (rate ratio 0.48; 95% CI 0.23, 0.99),
                           although the wide confidence intervals raise uncertainty on the
                           magnitude of effect. There was no statistically significant
                           difference in PE rates between treatment groups.
                           The sponsor provided in its Pre-PBAC response an analysis of the
                           proportion of patients with PDPE events for the pooled data of
                           CF-301 and CF-302 (to allow comparison to other studies).
Indirect comparison (CF-301/CF-302 vs. Fuchs 1994)
                           The outcomes of the indirect comparison are change in
                           FEV1 (%) from baseline and risk of PDPE events.
                           Based on the indirect analyses, the submission claimed DPI mannitol
                           and dornase alfa were comparable in terms of improving lung
                           function and reducing the risk of exacerbations.
                           The PBAC noted that the outcome of change in FEV1 from
                           baseline differed between trials. Results from the CF-301 and
                           CF-302 trials were based on the mean change in FEV1 from
                           baseline to Week 26 (end of the study) while the results from the
                           Fuchs et al (1994) trial were based on the overall change in
                           FEV1 from baseline averaged across multiple time points
                           throughout the study (4, 8, 12, 16, 20 and 24 weeks).
                           
                        
The outcome of risk of PDPE events differed between trials. Results from the CF-301 and CF-302 are based on the annualised rate of PDPE events while the results from the Fuchs et al (1994) trial are based on the proportion of patients with PDPE events adjusted for baseline differences in age between treatment arms.
The PBAC also noted the common comparator arms were not the
                           same; the DPI mannitol trials (CF-301/CF-302) had sub-therapeutic
                           dose of mannitol in the control arm and potential concomitant use
                           of dornase alfa, whereas the dornase alfa trial (Fuchs) had a
                           placebo control.
For PBAC’s view, see Recommendation and
                              Reasons.
                           The PBAC noted that similar proportions of patients in the DPI
                           mannitol and control (sub-therapeutic mannitol) treatment arms
                           experienced adverse events during the CF-301/CF-302 trials.
                           Patients were more likely to experience treatment-related events in
                           the DPI mannitol arm (mainly cough and haemoptysis) compared to
                           control. In the CF-301 trial, DPI mannitol was associated with a
                           higher incidence of withdrawals due to adverse events compared to
                           placebo (16% vs. 8%). There were no published long-term safety data
                           on DPI mannitol beyond the 6 month timeframe of the clinical
                           trials.
                           Adverse events associated with dornase alfa include: voice
                           alteration, rash, haemoptysis, dyspnoea, pharyngitis and
                           laryngitis. There were insufficient data to assess whether DPI
                           mannitol and dornase alfa have comparable safety profiles.
9. Clinical Claim
Monotherapy for patients who are intolerant or unresponsive to dornase alfa (comparator retrial of dornase alfa):
                           The submission claimed DPI mannitol as being similarly effective to
                           dornase alfa with a similar safety profile to dornase alfa.
Add-on therapy to dornase alfa for patients who have an inadequate response to dornase alfa (comparator is placebo as add-on to dornase alfa):
                           The submission claimed that DPI mannitol is more effective than
                           placebo/control at improving FEV1 outcomes in subjects with cystic
                           fibrosis either as monotherapy or when used in combination with
                           dornase alfa. DPI mannitol had higher rates of adverse
                           events related to treatment and higher rates of withdrawal due to
                           adverse events than placebo/control. 
For the PBAC’s view, see Recommendation and
                              Reasons.
10. Economic Analysis
                           The submission presented two economic evaluations:
                           Monotherapy:
                           
                        
- A cost-minimisation analysis of DPI mannitol monotherapy compared to dornase alfa.
Add-on:
- A modelled cost utility analysis of dornase alfa with DPI mannitol add-on therapy compared with dornase alfa alone.
Cost minimisation (DPI mannitol monotherapy vs. dornase alfa monotherapy)
                           The submission claimed that DPI mannitol (400 mg twice a day) is
                           equivalent to dornase alfa (2.5 mg once a day) based on the daily
                           dose used in the included trials.
                           The comparative cost of DPI mannitol was less than dornase
                           alfa.
Cost effectiveness (dornase alfa with DPI mannitol add-on therapy vs. dornase alfa)
                           The submission presented an economic model that compared the costs
                           and health outcomes associated with usual care, DPI mannitol alone,
                           dornase alfa alone, and the combination of DPI mannitol with
                           dornase alfa in patients with cystic fibrosis.
                           The submission assumed that the combined results of the control
                           arms of studies CF-301/CF-302 (which compared DPI mannitol to
                           sub-therapeutic mannitol) could represent the efficacy of dornase
                           alfa alone in the economic model.
                           The economic model assumed that the short-term (26 week)
                           improvement in lung function (FEV1) associated with DPI
                           mannitol treatment compared to control would be maintained beyond
                           the clinical trial duration.
                           The model assumed that DPI mannitol treatment would reduce
                           exacerbations compared to control. The risk of exacerbations was a
                           key driver of the economic model. An incremental cost per quality
                           adjusted life year gained was calculated to be between
                           $45,000-$75,000.
                           The results of the sensitivity analyses indicated that the model
                           was most sensitive to continuation rules, price of DPI mannitol and
                           the risk of exacerbations. The sensitivity analyses presented in
                           the submission suggested that removing the continuation rule or
                           increasing the requirement to a 10% FEV1 improvement
                           will lead to higher ICERs compared to the base case (5%
                           FEV1 improvement).
                           The PBAC noted that the clinical trial data presented in the
                           submission did not show a statistically significant reduction in
                           exacerbations with DPI mannitol add-on therapy. Assuming that
                           patients treated with DPI mannitol have the same risk of
                           exacerbation as control patients this increased the ICER from to
                           between $75,000-$105,000 per QALY.
For PBAC’s view, see Recommendation and
                              Reasons.
11. Estimated PBS Usage and Financial Implications
                           The financial cost per year to the PBS was estimated by the
                           submission to be less than $10 million in the fifth year of
                           listing. The PBAC considered this an overestimate as the submission
                           did not include the proposed continuation rules in its estimates
                           and did not include any cost-offsets due to drug
                           substitution.
12. Recommendation and Reasons
                           The PBAC considered the clinical place of mannitol was uncertain.
                           The PBAC noted a clinician’s comments at the hearing
                           regarding the place of mannitol in CF therapy. The
                           clinician’s comments did not support the pre-PBAC response
                           which suggested that the place of mannitol would be as a
                           ‘last resort’ when other treatment options had failed.
                           The clinician suggested that a PBS listing for mannitol was
                           appealing as it provides a unique option for treatment of CF which
                           does not require nebulisation. Whilst sympathetic with the notion
                           of CF patients looking for alternatives to nebulised forms of
                           treatment, the PBAC considered the twice daily regimen for mannitol
                           of 10 capsules via inhaler, with 5-15minutes of bronchodilator
                           prior to use, was complex and intensive, particularly for children,
                           and could possibly result in reduced compliance.
                           The ACPM recommendation for use of mannitol in second-line reflects
                           the sponsor’s proposed listing, however, trial data show
                           there may be broader use for mannitol in CF.
                           The proposed comparator of a re-trial of dornase alfa, in patients
                           intolerant or unresponsive to dornase alfa, was not accepted.
                           Patients not responding to dornase alfa would not be likely to try
                           it again, nor would they qualify under the continuation criteria
                           for dornase alfa. Placebo, or hypertonic saline should have been
                           considered relevant comparators. The clinician considered mannitol
                           to be sufficiently different to hypertonic saline due to the
                           different forms of administration. However, the PBAC did not accept
                           the unique delivery mechanism of mannitol as a sufficient reason to
                           exclude hypertonic saline as a relevant comparator.
                           The PBAC questioned the applicability of the trial populations to
                           the proposed PBS listings and overall, considered the evidence to
                           support the proposed listings was uncertain. Dornase alfa and
                           mannitol have separate mechanisms of action. The PBAC was not
                           convinced that combination use of these drugs would not lead to
                           worse outcomes. Although acknowledging that trial CF-203 was
                           underpowered and the larger trials of CF-301/CF-302, which had
                           subgroups of patients on either both treatments or mannitol
                           monotherapy, did not show a consistent trend of patients performing
                           worse when the using mannitol in combination with dornase alfa, the
                           benefit of mannitol as an add-on therapy remains uncertain. Trial
                           data also did not support the monotherapy listing for patients who
                           had failed to achieve an adequate response to dornase alfa. The
                           indirect comparison with Fuchs (1994) is highly uncertain because
                           of a lack of exchangeability and differences in the outcome
                           measures between the trials.
                           There were no statistically significant differences in exacerbation
                           rates, use of rescue antibiotics, or hospitalisations between
                           mannitol and control in CF-301/CF-302 populations. There was also
                           no statistically significant difference in exacerbation rates
                           between mannitol and control in patients using concomitant dornase
                           alfa.
                           The economic model to support the proposed add-on restriction
                           resulted in a high and uncertain ICER. The model was dependent on a
                           number of assumptions (e.g. reduction in exacerbation events,
                           maintenance of treatment effect) that were not well justified in
                           the submission. The key source of uncertainty was the use of
                           different exacerbation rates between mannitol and control in the
                           model when this was not demonstrated to be statistically
                           significant in the trials. Given the use of dornase alfa in some,
                           but not all patients in the two key trials, the data used in the
                           model was not appropriate.
                           The cost-minimisation in the monotherapy setting remained highly
                           uncertain, even with the offer a lower price than dornase
                           alfa.
                           The PBAC therefore rejected the submission because the comparator
                           when dornase alfa has failed was inappropriate and because of
                           uncertain effectiveness and resulting uncertain cost effectiveness,
                           when used in combination with dornase alfa.
                           The PBAC also acknowledged and noted the consumer comments on this
                           item.
Recommendation:
Reject
13. Context for Decision
                           The PBAC helps decide whether and, if so, how medicines should be
                           subsidised in Australia. It considers submissions in this context.
                           A PBAC decision not to recommend listing or not to recommend
                           changing a listing does not represent a final PBAC view about the
                           merits of the medicine. A company can resubmit to the PBAC or seek
                           independent review of the PBAC decision.
14. Sponsor’s Comment
                           Pharmaxis believes that a lack of available prescribing data has
                           lead to misunderstandings and incorrect conclusions on how existing
                           therapies are used in cystic fibrosis. Pharmaxis is now working
                           with the CF community to provide evidence on current use of CF
                           treatments to allow a better assessment of the true place of
                           Bronchitol in therapy, and an appropriate comparator for patients
                           who are not responding to currently available treatments. 




