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August 8, 2021


Beginning in December of 2020, the Mastocytosis Society of Canada (MSC) began receiving reports from patients of concerns regarding Nalcrom. The medication Nalcrom (also known as Cromolyn Sodium Oral) is recognised as a first line therapy in the management of the symptoms of mast cell disorders which include abdominal pain, diarrhea, nausea, bone pain, cognitive dysfunctions, and anaphylaxis. Nalcrom is recognized as a "mainstay" or "key" medication for patients with mastocytosis and other related mast cell disorders. Canadian patients rely exclusively on Sanofi Canada to supply Nalcrom as there is no other approved version of this medication in Canada.

Following these reports, MSC conducted a patient survey from February 12, 2021, to March 15, 2021. Of 55 returned surveys, thirty-nine (39) reported physical changes to the medication (significantly less full capsules and dissolving challenges). Upon follow up, 22 reports of adverse events were coincident with the commencement of batches with identified appearance changes. Adverse events included reports of anaphylaxis (4, including 3 reports of multiple instances of anaphylaxis), gastrointestinal symptoms (18), allergic-like symptoms (14, including hives, flushing, itching) and one (1) pediatric case. Eight (8) respondents indicated that their adverse reactions were eliminated by returning to older Nalcrom batches or compounded cromolyn sodium. For a complete summary of the survey results see the report on our website and the additional updates we have provided.

Post-Shortage Update on Quality Concerns with Nalcrom

Sanofi Canada declared a shortage on March 3, 2021, that was extended on April 23, 2021 to May 21, 2021. The shortage was declared resolved May 21 2021 on the Health Canada drug shortages website. During this almost 3-month period, patients reliant on Nalcrom for symptom management of their rare disease had no access to any alternative option(s) to replace this medication.

After the shortage was declared resolved by Sanofi on May 21, 2021, patients continued having difficulty accessing Nalcrom from their pharmacy well into July, 2021. Of the few patients who have been able to access the new batch of Nalcrom released after the shortage (Lot 00078N and lot 00104N; exp. Mr/24), 8 have reported continued issues with the quality of the Nalcrom capsules, citing nausea, diarrhea, abdominal pain, anaphylaxis and an overall increase in symptoms.

We have been informed by at least 4 patients that their adverse events were reported to Sanofi Canada since June, 2021 using the new batches of Nalcrom (00078N and 00104N). While this may appear to be a reduction in reports of adverse events since the release of the June 2021 Nalcrom batches, we would like to highlight that many patients have informed us they have either have not been able to access the latest Nalcrom batch from their pharmacy or have entirely switched to compounded sodium cromoglycate while quality issues remain unresolved.

All MSC survey respondents have been encouraged to report adverse events directly to Sanofi Canada and Health Canada. An examination of the Health Canada Adverse Event Database also points to a spike in adverse event reporting on the drug Nalcrom since December 2020. There have been a total of 41 AE reports on Nalcrom since 1982. Between 1982 and 2019, there were a total of 23 for a rate of 0.62 adverse event reports per year. Between December 18, 2020 and March 31 2021, there have been 18 adverse event reports. This is equivalent to a rate of 54 adverse events per year. This represents an 87-fold increase in adverse event reporting. The database does not show any reports beyond March 31, 2021, however based on our communications with our rare disease patient population we expect there to be more. We have reached out personally to every patient that has reported adverse events to MSC to confirm that they have also reported this to Health Canada and Sanofi Canada. We are continuing to follow up with patients to encourage further adverse event reporting.

Quality concerns with the drug Nalcrom is an ongoing issue within our patient population, both with old batches from Fall/Winter 2020 and new batches released in June 2021. It has been 9 months since our patient population first identified quality issues with the Nalcrom batches. Thus far, the investigations by Sanofi Canada and Health Canada remain ongoing and there has been no resolution. Our patients have no alternative medications and accessing the compounded sodium cromoglycate is not a sustainable solution, as it is not covered by public and private insurance plans and has been reported as less effective than the marketed Nalcrom (prior to the recent quality issues). There has been no communication from Sanofi Canada or Health Canada since July 2, 2021.



Monday, May 3, 2021


Dear Members of our Community, 


We are writing to provide an update regarding the medication called Nalcrom and our recent discussions with Sanofi Canada. On March 4, 2021, we shared an update with our patient population regarding the declared shortage of Nalcrom by Sanofi Canada. This shortage declaration by Sanofi Canada was made in response to significant concerns raised by patients with the quality and efficacy of the recent batches of Nalcrom distributed to patients in Canada. The declared shortage by Sanofi Canada, available on the Drug Shortages Canada website, stated that the estimated end date would be on April 23, 2021. 


On April 23, 2021, Sanofi Canada revised this submission to Drug Shortages Canada and extended the estimated end-date of the shortage to May 21, 2021. We are concerned about this extension and have reached out to both Sanofi Canada and Health Canada to follow up on this and advocate on behalf of our patient population.


If patients are unable to access the medication Nalcrom during this declared shortage, some patients have reported to us the option of accessing the medication through a compounding pharmacy. In this instance, patients have been able to work in partnership with their prescribing healthcare practitioners and a compounding pharmacy to access the drug sodium cromoglicate (the active drug within Nalcrom medication). For any further inquiries about compounding medication we recommend you reach out to your prescribing physician and the nearest compounding pharmacy to you. Included here is a link to the Association of Compounding Pharmacist of Canada, which includes a map with many available compounding pharmacies across Canada. 


In regards to cost, we recognise that the cost of the medication Nalcrom is a financial burden for many patients and recognise that many insurance and public pharmacare plans do not cover compounded medications. Some patients have shared with us that they have been able to have their insurance companies cover the costs of the compounded version of the medication upon provision of proof of the current shortage. Examples of documentation include the official notice on Drug Shortages Canada and links to our website updates. Although we recognize that  not all patients will be able to have the compounded medication financially covered by an insurance company, we share this information for those that it might be relevant to.


We will continue to advocate for the timely resolution of both the shortage and the quality complaints regarding the Nalcrom medication. Following the resolution of the shortage, we plan to take steps to advocate for greater stability of access to the Nalcrom drug and better financial coverage of the medication in private and public drug plans. We will provide updates as they become available. 


If there are any additional questions please do not hesitate to reach out to caitlin@mastocytosis.ca.



Thursday March 4, 2021


Dear Members of our Community, 


We are writing to provide an update regarding the medication called Nalcrom and our recent discussions with Sanofi Canada. In December 2020, we were informed by members of our patient community of concerns with the quality and efficacy of the Nalcrom medication from the most recent batches. Concerns regarding the quality of the medication were raised in conjunction with concerns regarding the supply of the medication, with many patients expressing to us difficulties accessing the medication from their pharmacy. 


We took action by launching a survey to collect information on both the supply challenges and the quality concerns that had been raised to us. This survey launched February 12, 2021 and will remain open until March 15, 2021. 


Despite the survey continuing to collect responses until March 15, 2021, we took immediate steps to address this issue. Since February 2, 2021 we have participated in weekly meetings with a representative from Sanofi Canada. We shared with them the preliminary results of our survey (now 48 respondents) and advocated on behalf of our patient population  the need to investigate and promptly resolve the quality and efficacy complaints that had been raised by patients. On February 26, 2021, we sent a letter to Health Canada to make them aware of the current situation, share with them our preliminary survey results, and request their support in resolving concerns raised by our patient population related to the most recent batches of Nalcrom. Our letter has been received by the Health Canada Regulatory Operations and Enforcement Branch (ROEB) and Health Product Compliance Directorate (HPCD). Our letter has also been forwarded to the Canada Vigilance Program.  We will share any follow-up information.


Yesterday, March 3, 2021, we had a follow up call with a Sanofi Canada representative and were informed that based on adverse events reported by individual patients and the information we have shared with them, that they are taking additional steps to investigate and examine the next batch of Nalcrom medication that will be distributed in Canada. To ensure that they are able to conduct the reviews of the next batch that they deem necessary, Sanofi Canada on March 2, 2021 declared a temporary shortage of the Nalcrom medication. The company anticipates that the medication will once again become available to patients in Canada on April 23, 2021. We have attached to this statement a copy of the letter that Sanofi Canada has provided to all of your healthcare professionals on the matter.


We realize that this update will come as a disappointment to many of those in our patient population, however we  wanted to share this new information as soon as possible to allow you to make decisions based on all current information. We will share additional updates as they become available.


We will continue to advocate on behalf of our patient population and have ensured that both Sanofi Canada and Health Canada know that this is a medication for a rare disease population that has no generic source of accessing this medication. We encourage individuals that have concerns regarding the quality of and/or experience adverse events to the most recent batches of Nalcrom medication to inform Sanofi Canada and Health Canada directly.  You can raise concerns over a medication and file a complaint by calling Sanofi Canada at 1-800-265-7927. Regarding Health Canada you can submit an Adverse Event Form through this link. If the link doesn't work there is more information on this website about submitting your concerns directly (by email or phone).


Following the resolution of the current quality investigation and declared shortage we have arranged with Sanofi Canada to work collaboratively towards addressing the longstanding supply issues that patients have experienced with Nalcrom. We want to reiterate, however, that at the moment our key priority is resolving the Nalcrom medication quality concerns and the newly declared shortage. We are actively working towards ensuring that individuals living with mast cell diseases have access to Nalcrom medication as soon as possible and have made clear the current situation poses risks to this rare disease population. 


If the newly declared shortage will affect you or someone you are caring for we recommend that patients reach out to their prescribing healthcare professional to discuss the appropriate next steps.


At this time we have shared with you all of the information that we currently have about the situation, however, please do not hesitate to reach out if you have any additional questions.


Warm wishes,


Caitlin (on behalf of the MSC Board of Directors)


Caitlin Salvino (she/her)

Director, Mastocytosis Society of Canada



Download:  Download the letter from Sanofi