Last updated: October 31, 2026
Accretropin was a recombinant human growth hormone, or somatropin, developed and marketed by Cangene Corporation in the United States. The FDA approved it in 2007 for pediatric growth hormone indications, but the product was later voluntarily discontinued. Accretropin did not establish a durable commercial position against established somatropin brands such as Genotropin, Humatrope, Norditropin, Nutropin AQ, Saizen, and Omnitrope. Public filings do not report standalone Accretropin revenue, and the product has no identifiable current commercial franchise.
What was Accretropin and who marketed it?
Accretropin was somatropin produced through recombinant DNA technology. Its label covered pediatric patients with growth failure associated with growth hormone deficiency, Turner syndrome, and idiopathic short stature under specified clinical criteria.[1]
| Item |
Accretropin detail |
| Active ingredient |
Somatropin, recombinant human growth hormone |
| Dosage form |
Injectable solution |
| U.S. sponsor |
Cangene Corporation |
| FDA pathway |
Biologic license application |
| FDA approval |
2007 |
| Primary market |
U.S. pediatric growth hormone therapy |
| Commercial status |
Voluntarily discontinued |
| Current revenue disclosure |
No standalone public revenue reported |
| Current patent position |
No identifiable live, product-specific commercial patent estate |
Cangene was a Canadian biotechnology company focused on biologics, plasma-derived products, and biodefense products. Accretropin was one of several commercial products in its portfolio, but public financial reporting did not provide a separate revenue line for the brand.[2]
Emergent BioSolutions acquired Cangene in 2014 in a transaction valued at approximately $222 million. By the time of the acquisition, Accretropin did not represent a separately disclosed growth asset in Emergent’s public financial materials.[3]
When did Accretropin lose exclusivity and commercial momentum?
Accretropin’s commercial exclusivity was limited by the structure of the somatropin market rather than by a single major patent expiry.
The product entered a crowded market in which several recombinant growth hormone products already had physician familiarity, distribution networks, reimbursement contracts, and established pediatric endocrinology relationships. Somatropin products were clinically similar but competed through device design, dosing convenience, payer access, patient-support programs, and specialty-pharmacy execution.
Accretropin exclusivity timeline
| Date or period |
Event |
Commercial implication |
| 2007 |
FDA approval of Accretropin |
Entry into an established somatropin market |
| 2007-2011 |
Commercial availability |
Limited public evidence of material market share |
| Early 2010s |
Product withdrawal or discontinuation |
Loss of active commercial presence |
| 2014 |
Cangene acquired by Emergent BioSolutions |
No separately disclosed Accretropin growth strategy |
| 2019 onward |
Twelve-year reference-product period potentially relevant under the BPCIA framework for eligible biologics |
No meaningful Accretropin commercial recovery |
The precise commercial discontinuation date should be distinguished from the end of patent protection. FDA product records identify Accretropin as discontinued, but discontinuation does not itself establish that all patents covering somatropin, manufacturing processes, devices, or formulations had expired.[4]
The practical loss of exclusivity occurred when the product could no longer compete for prescriptions and payer coverage. By then, the market had multiple branded and follow-on somatropin products.
What is the FDA regulatory status of Accretropin?
Accretropin is not an actively marketed U.S. growth hormone product. FDA records treat it as a discontinued biologic product rather than a current commercial reference product.[4]
The product’s regulatory history matters for three reasons:
- A discontinued status reduces the commercial value of any residual brand, manufacturing, or formulation rights.
- A discontinued biologic creates supply and continuity issues for patients who need long-term pediatric therapy.
- A later acquirer would face reactivation, manufacturing validation, pharmacovigilance, and market-access costs before generating revenue.
Accretropin’s approval was based on the safety and efficacy record for recombinant somatropin. The clinical category itself remains active, but Accretropin no longer participates meaningfully in that market.
What patents protected Accretropin?
There is no publicly identifiable current patent estate that gives Accretropin material exclusivity as a commercial product.
Somatropin products can be protected by several patent categories:
- Composition claims covering engineered growth hormone sequences.
- Host-cell and recombinant production claims.
- Protein purification and refolding processes.
- Stabilized liquid formulations.
- Cartridge, pen, vial, or injection-device designs.
- Method-of-use claims for pediatric growth disorders.
- Manufacturing and quality-control processes.
Most foundational recombinant somatropin patents predated Accretropin’s approval and were approaching expiration or had expired by the time of launch. Product-specific protection, if any, would have depended on later formulation, process, packaging, or device patents rather than on a broad composition patent covering natural human growth hormone.
Did Accretropin have Orange Book listings?
No conventional Orange Book analysis applies to Accretropin in the same manner as it does to a small-molecule drug. Biologics licensed under the Public Health Service Act are generally tracked through FDA biologic records and the Purple Book rather than through Orange Book patent listings.[5]
Accretropin therefore did not have the same Paragraph IV litigation pathway associated with an abbreviated new drug application for a small-molecule product.
Were there Paragraph IV challenges to Accretropin?
No major public Paragraph IV challenge is associated with Accretropin. The principal reason is regulatory classification. A generic applicant typically would not use the ordinary ANDA Paragraph IV mechanism to challenge a biologic licensed under the Public Health Service Act.
For somatropin, competitive entry historically occurred through a combination of:
- Earlier 505(b)(2) pathways for certain follow-on products.
- Biologic licensing pathways.
- Later biosimilar applications under the Biologics Price Competition and Innovation Act.
- Brand-to-brand competition among recombinant products.
How strong was the Accretropin patent estate?
Accretropin’s patent estate was weak as a standalone commercial asset.
| Patent-strength factor |
Assessment |
| Core active ingredient protection |
Weak; somatropin was a mature biological product |
| Formulation protection |
Potentially relevant but unlikely to support durable brand economics |
| Device protection |
Possible, but not clearly specific to Accretropin |
| Manufacturing barriers |
Moderate; biologic production requires validated processes and controls |
| Regulatory exclusivity |
Time-limited |
| Trademark value |
Low after discontinuation |
| Litigation deterrence |
Low based on the absence of material public patent litigation |
The strongest residual barrier was not necessarily intellectual property. It was manufacturing know-how, analytical comparability, process validation, and regulatory execution. A replacement manufacturer would need to demonstrate consistent potency, purity, stability, sterility, and product quality.
Those barriers can delay entry, but they do not create durable commercial protection when competing somatropin products already have manufacturing infrastructure and payer relationships.
What formulations and delivery systems competed with Accretropin?
Growth hormone products compete through delivery systems as much as through molecular identity. Accretropin was supplied as an injectable product, while competitors used combinations of vials, cartridges, injection pens, and specialty devices.
| Competitor |
Company historically associated with product |
Competitive feature |
| Genotropin |
Pfizer |
Established pediatric endocrinology franchise and pen systems |
| Humatrope |
Eli Lilly |
Broad physician and payer presence |
| Norditropin |
Novo Nordisk |
Strong specialty-pharmacy and device platform |
| Nutropin AQ |
Genentech/Roche |
Liquid formulation and established clinical use |
| Saizen |
Merck Serono |
Pen-based administration and international presence |
| Omnitrope |
Sandoz |
Follow-on somatropin positioning and price competition |
Accretropin lacked the scale to make delivery-device differentiation a durable advantage. In growth hormone, adherence support, injection convenience, caregiver education, and insurance approval often influence product selection.
How did the competitive landscape affect Accretropin revenue?
The financial trajectory was likely constrained from launch.
Cangene did not disclose Accretropin net sales as a separate line item in its publicly available reporting. The company’s financial statements aggregated product revenues across its portfolio, preventing a reliable calculation of Accretropin sales, gross margin, or contribution profit.[2]
Several market forces limited the product’s financial potential:
- Established competitors already occupied formulary and specialist channels.
- Pediatric growth hormone treatment requires long-term patient retention.
- Payers negotiate aggressively across clinically substitutable somatropin products.
- Specialty distribution and patient-support infrastructure increase selling costs.
- Manufacturing interruptions can cause physicians to switch patients permanently.
- A smaller supplier has less leverage with payers and specialty pharmacies.
The absence of separately reported revenue does not prove that Accretropin generated no sales. It indicates that the product was not material enough to be reported as a distinct public segment or brand-level financial asset.
What revenue exposure did Cangene and Emergent have?
Accretropin appears to have had low revenue concentration within the Cangene portfolio. Cangene’s broader business included biologics, plasma-derived therapies, and government-related products. Its value to an acquirer was assessed at the portfolio level rather than through a disclosed Accretropin valuation.[3]
Emergent’s acquisition of Cangene was driven by a broader product and pipeline rationale, including biodefense and specialty-biologic assets. Accretropin was not identified in public reporting as a major revenue driver, core growth platform, or material litigation asset.
This creates a clear distinction between corporate transaction value and Accretropin brand value. The Cangene acquisition price cannot be allocated to Accretropin without a company valuation model or transaction-level asset allocation that was not publicly reported.
What generic, biosimilar, and replacement-entry risks existed?
Accretropin faced replacement-entry risk from both follow-on somatropin products and established brands.
Biosimilar risk
The BPCIA created a pathway for biosimilar versions of biologics, but Accretropin’s discontinuation reduced its practical value as a reference product. A discontinued product has weaker commercial relevance for biosimilar competition because physicians and payers are more likely to compare against active somatropin brands.
The principal market risk was therefore not a wave of biosimilars targeting Accretropin specifically. It was substitution by other available somatropin products.
Generic launch scenarios
An ANDA-style generic launch was not the expected route for a Public Health Service Act biologic. More realistic scenarios were:
- A biosimilar or follow-on somatropin product competing with active reference brands.
- A branded somatropin supplier acquiring or relaunching Accretropin assets.
- A contract manufacturer using existing somatropin know-how to supply a replacement product.
- No relaunch because development and payer-acquisition costs exceed the residual brand value.
The fourth scenario is the most commercially consistent with Accretropin’s discontinued status and crowded market.
What patent litigation and settlement agreements affected Accretropin?
No material public patent litigation or settlement agreement is associated with Accretropin as a standalone product. The lack of major litigation is consistent with its limited commercial scale and biologic regulatory pathway.
Patent disputes involving other somatropin products do not automatically create legal exposure for Accretropin. Any assessment would require product-specific review of asserted claims, manufacturing methods, devices, and settlement terms. No such Accretropin-specific dispute is prominent in the public record.
How does Accretropin compare with competing growth hormone products?
Accretropin was disadvantaged on commercial scale, market access, and product continuity.
| Factor |
Accretropin |
Established competitors |
| Market tenure |
Short |
Long |
| Specialist adoption |
Limited public evidence |
Broad |
| Payer contracting |
Not separately disclosed |
Developed |
| Device differentiation |
Limited |
More extensive |
| Revenue visibility |
No standalone disclosure |
Greater corporate disclosure |
| Patent leverage |
Limited |
Product- and device-specific portfolios |
| Supply continuity |
Discontinued |
Active for leading products |
| Acquisition value |
Portfolio-level only |
Supported by broader franchises |
Accretropin’s clinical identity as somatropin was insufficient to overcome the commercial advantages held by larger manufacturers.
Key Takeaways
- Accretropin was an FDA-approved recombinant somatropin product marketed by Cangene Corporation.
- The product was voluntarily discontinued and is not an active commercial growth hormone brand.
- Public filings do not disclose standalone Accretropin revenue, profit, or market share.
- Its commercial exclusivity was limited by a mature, crowded somatropin market.
- Accretropin did not have a conventional Orange Book patent strategy or a major Paragraph IV litigation profile.
- The remaining barriers were primarily manufacturing, quality, regulatory, and distribution barriers rather than strong product-specific patent rights.
- Cangene’s acquisition by Emergent BioSolutions does not establish a separate valuation for Accretropin.
- The most material competitive threat was substitution by active somatropin brands and follow-on products, not generic entry directed specifically at Accretropin.
FAQs
Is Accretropin still available in the United States?
No. Accretropin is listed as a discontinued biologic product and is not an active U.S. somatropin brand.
Did Pfizer or Novo Nordisk acquire Accretropin?
No public transaction identifies Pfizer, Novo Nordisk, Eli Lilly, or another leading growth hormone company as acquiring Accretropin. Cangene was acquired by Emergent BioSolutions.
Was Accretropin a biosimilar?
No. Accretropin was an original FDA-approved recombinant somatropin product, not a biosimilar designated under the modern BPCIA pathway.
Does Accretropin have an active U.S. patent blocking relaunch?
No publicly identifiable active product-specific patent has been established as a meaningful commercial barrier to relaunch. Manufacturing validation and regulatory requirements would be more important obstacles.
What replaced Accretropin in the growth hormone market?
Patients and prescribers could use other somatropin products, including Genotropin, Humatrope, Norditropin, Nutropin AQ, Saizen, and Omnitrope, subject to clinical suitability and payer coverage.
References
-
U.S. Food and Drug Administration. (2007). Accretropin (somatropin) prescribing information. FDA.
-
Cangene Corporation. (2013). Annual report and consolidated financial statements. Cangene Corporation.
-
Emergent BioSolutions Inc. (2014). Emergent BioSolutions completes acquisition of Cangene Corporation. Emergent BioSolutions.
-
U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations and discontinued drug product records. FDA.
-
U.S. Food and Drug Administration. (n.d.). Purple Book: Database of licensed biological products. FDA.
