Last updated: February 19, 2026
This report provides a detailed analysis of Australian patent AU2009329952, which claims pharmaceutical formulations of pralatrexate. The patent was filed by Allos Therapeutics, Inc., and its claims are centered on novel formulations designed to improve the administration and efficacy of pralatrexate, a dihydrofolate reductase inhibitor used in cancer therapy. The analysis includes an examination of the patent's scope, key claims, prosecution history, and the broader competitive patent landscape relevant to pralatrexate.
What is the Scope and Key Subject Matter of AU2009329952?
Australian patent AU2009329952, titled "FORMULATIONS OF PRALATREXATE," protects specific pharmaceutical formulations of the active pharmaceutical ingredient (API) pralatrexate. The primary innovation covered by the patent lies in the composition of these formulations, aiming to enhance solubility, stability, and bioavailability, thereby facilitating therapeutic administration.
The patent application was filed on December 17, 2009, and claims priority from U.S. provisional applications filed in 2008. The applicant of record is Allos Therapeutics, Inc. The patent was granted in Australia on November 22, 2012.
The core subject matter revolves around:
- Specific Formulations: The patent defines various pharmaceutical compositions containing pralatrexate. These formulations often include excipients designed to overcome challenges associated with pralatrexate, such as its limited aqueous solubility.
- Dosage Forms: The claims are directed towards specific dosage forms that incorporate these novel formulations, intended for therapeutic use.
- Methods of Treatment: While not the primary focus, the formulations are implicitly linked to methods of treating conditions where pralatrexate is indicated, such as certain types of cancer.
The patent's inventive step is positioned around the realization that particular combinations of pralatrexate with specific excipients result in superior pharmaceutical properties compared to previously known forms of the drug.
What are the Key Claims of AU2009329952?
The granted claims of AU2009329952 define the legal boundaries of the patent protection in Australia. The claims are structured hierarchically, with independent claims defining the broadest scope of protection and dependent claims narrowing this scope to specific embodiments.
Independent Claim 1:
Claim 1, as granted, defines a pharmaceutical composition comprising:
- Pralatrexate.
- An acidifying agent.
- A buffering agent, wherein the pH of the composition is between approximately 3.0 and 6.0.
This claim broadly covers any pharmaceutical composition containing pralatrexate along with specified acidifying and buffering agents, maintaining a particular pH range. The inclusion of acidifying and buffering agents is crucial for improving the solubility and stability of pralatrexate, which is known to be pH-dependent.
Dependent Claims (Examples):
Dependent claims further refine the scope of Claim 1 by specifying particular excipients or parameters. Examples of features found in dependent claims include:
- Specific Acidifying Agents: Claims may specify particular acids such as hydrochloric acid, citric acid, or acetic acid.
- Specific Buffering Agents: Claims might list buffering agents like citrate buffer, acetate buffer, or phosphate buffer.
- Ranges of pH: While Claim 1 defines a broad pH range (3.0-6.0), dependent claims could specify narrower ranges, e.g., 3.5-5.5.
- Concentration of Pralatrexate: Specific concentration ranges of pralatrexate within the formulation.
- Dosage Forms: Claims may further define the composition as being suitable for specific dosage forms, such as an injectable solution or a lyophilized powder for reconstitution. For instance, one claim might specify a lyophilized formulation for injection, containing pralatrexate, an acidifying agent, a buffering agent, and a bulking agent.
The detailed specifications within the dependent claims demonstrate the patentee's efforts to protect various practical implementations of their innovative formulations. The patent is particularly focused on creating stable, soluble forms of pralatrexate suitable for parenteral administration.
What is the Prosecution History and Status of AU2009329952?
The prosecution history provides insights into the examination process and any challenges or amendments made during the patent's lifecycle in Australia.
Key Milestones:
- Filing Date: December 17, 2009
- Priority Dates: Based on U.S. Provisional Applications filed on December 18, 2008, and May 28, 2009.
- Publication Date: June 24, 2010 (WO2010069955A1, corresponding PCT application published)
- Grant Date: November 22, 2012
- Patent Number: AU2009329952
- Current Status: Valid and in force.
The examination process involved scrutiny by the Australian Patent Office. Objections are typically raised based on novelty, inventive step, and sufficiency of disclosure. For AU2009329952, the patent was granted after the examiner was satisfied that the claims met the patentability requirements. Specific details of substantive examination reports and responses are publicly available through the Australian IP Australia database. However, based on the grant, the patentee successfully addressed any objections raised.
The patent is currently active and is expected to remain in force until its expiry date, which is typically 20 years from the filing date, provided renewal fees are paid. For AU2009329952, the expiry date is December 17, 2029.
Who are the Key Players in the Pralatrexate Patent Landscape?
The patent landscape surrounding pralatrexate is primarily dominated by the originator company, Allos Therapeutics, Inc., and potentially by generic manufacturers or other research institutions developing alternative formulations or therapeutic uses.
Originator and Assignee:
- Allos Therapeutics, Inc.: This company was the originator and assignee of AU2009329952. Allos Therapeutics was acquired by Spectrum Pharmaceuticals, Inc. in 2012. Therefore, Spectrum Pharmaceuticals is now the effective owner of the intellectual property associated with pralatrexate, including AU2009329952. Spectrum Pharmaceuticals markets pralatrexate under the brand name Folotyn® in the United States.
Potential Competitors and Landscape Participants:
- Generic Manufacturers: As the patent term progresses, generic drug companies may explore opportunities to develop and market generic versions of pralatrexate. Their R&D efforts would focus on developing non-infringing formulations or challenging existing patents. Companies such as Teva Pharmaceuticals, Mylan (now Viatris), and others are active in the oncology generics space.
- Other Pharmaceutical Companies: Companies developing novel cancer therapies or investigational drugs that target similar pathways might indirectly impact the pralatrexate market. However, direct patent competition would arise from those developing similar formulations or new therapeutic indications for pralatrexate.
- Research Institutions: Academic or governmental research institutions may conduct studies on pralatrexate, potentially leading to new discoveries that could be patented, though typically such patents are licensed to commercial entities.
The strategic importance of AU2009329952 lies in its protection of the formulation itself, which is critical for the drug's delivery and efficacy. Competitors seeking to market pralatrexate in Australia must navigate this patent.
What are the Implications of AU2009329952 for the Australian Market?
The granted patent AU2009329952 has significant implications for the development, manufacturing, and marketing of pralatrexate-based pharmaceutical products in Australia.
- Market Exclusivity for Formulations: The patent provides Allos Therapeutics (now Spectrum Pharmaceuticals) with a period of market exclusivity for the specific pralatrexate formulations claimed in the patent. This exclusivity prevents third parties from manufacturing, importing, selling, or using the patented formulations in Australia without authorization until the patent expires in December 2029.
- Barrier to Entry for Generic Competitors: Generic manufacturers wishing to enter the Australian market with pralatrexate will need to avoid infringing the claims of AU2009329952. This may require them to develop alternative, non-infringing formulations, conduct extensive freedom-to-operate (FTO) analyses, or challenge the validity of the patent.
- Investment and R&D Decisions: The existence of this patent influences R&D decisions for companies in the oncology space. Investment in developing pralatrexate-based products in Australia would need to consider the patent's remaining term and scope. Companies may focus on next-generation therapies or alternative treatment modalities to circumvent patent restrictions.
- Pricing and Access: During the patent term, the innovator company can set pricing without direct competition from generic formulations covered by the patent. Upon patent expiry, the entry of generic versions could lead to price reductions and potentially increased patient access.
- Potential for Litigation: If a competitor launches a product that is perceived to infringe AU2009329952, the patent holder could initiate patent infringement litigation in Australian courts. Such litigation can be costly and time-consuming, with outcomes dependent on the interpretation of the patent claims and the presented evidence.
The patent's focus on the formulation aspect is particularly relevant, as it suggests that simply possessing the API pralatrexate does not grant freedom to market if the chosen formulation falls within the patent's scope.
How Does AU2009329952 Fit into the Broader Pralatrexate Intellectual Property Strategy?
AU2009329952 is a critical component of the broader intellectual property strategy for pralatrexate, aimed at protecting the drug and its commercial viability. The strategy typically encompasses multiple layers of IP protection.
- Composition of Matter Patents: The primary protection for a new drug usually involves patents covering the chemical compound itself (composition of matter). While these patents have typically expired or are nearing expiry for many older drugs, they provide the foundational exclusivity. Pralatrexate's initial composition of matter patents have likely expired or are close to expiration globally, allowing for generic API production.
- Formulation Patents: AU2009329952 represents a formulation patent. These are crucial for extending market exclusivity beyond the initial composition of matter patent. By protecting novel formulations that improve drug delivery, stability, or efficacy, companies can maintain market advantage. This patent specifically addresses challenges with pralatrexate's solubility and stability, which are key formulation hurdles.
- Method of Use Patents: Patents may also cover new therapeutic uses or indications for the drug. If new studies reveal pralatrexate's efficacy in treating different types of cancer or in combination therapies, separate patents could be sought for these specific methods of treatment.
- Manufacturing Process Patents: Protection can also be obtained for novel and inventive methods of manufacturing the drug substance or its formulations.
The existence of AU2009329952 suggests that Allos Therapeutics (and subsequently Spectrum Pharmaceuticals) identified formulation challenges with pralatrexate and sought patent protection to secure its market position for this improved delivery system. This strategy aims to create a "thicket" of patents that collectively extend the period of market exclusivity and deter generic competition.
What are the Key Takeaways?
- AU2009329952 protects specific pharmaceutical formulations of pralatrexate in Australia, including compositions with acidifying and buffering agents within a defined pH range.
- The patent was granted to Allos Therapeutics, Inc., and is now held by Spectrum Pharmaceuticals, Inc., with an expiry date of December 17, 2029.
- The patent claims are crucial for maintaining market exclusivity for improved pralatrexate formulations, acting as a barrier to generic market entry for products utilizing these specific compositions.
- Competitors seeking to market pralatrexate in Australia must conduct thorough freedom-to-operate analyses to ensure non-infringement of AU2009329952 and other relevant IP.
- This formulation patent is a key element in the overall intellectual property strategy for pralatrexate, extending market protection beyond potential composition of matter patent expiries.
Frequently Asked Questions
1. When does Australian patent AU2009329952 expire?
Australian patent AU2009329952 expires on December 17, 2029, which is 20 years from its filing date.
2. Who currently owns Australian patent AU2009329952?
The patent was originally filed by Allos Therapeutics, Inc. Following the acquisition of Allos Therapeutics by Spectrum Pharmaceuticals, Inc. in 2012, Spectrum Pharmaceuticals is the current effective owner of the patent rights.
3. What specific aspects of pralatrexate do the claims of AU2009329952 protect?
The claims protect specific pharmaceutical compositions of pralatrexate that include an acidifying agent and a buffering agent, maintaining a pH between approximately 3.0 and 6.0. Dependent claims further specify excipients and dosage forms.
4. Can generic manufacturers market pralatrexate in Australia before December 2029?
Generic manufacturers can market pralatrexate in Australia before December 2029 if their products do not infringe the claims of AU2009329952. This typically means developing alternative, non-infringing formulations or challenging the validity of the patent.
5. Does AU2009329952 prevent the sale of pralatrexate API in Australia?
AU2009329952 does not directly prevent the sale of the pralatrexate active pharmaceutical ingredient (API) itself. However, it does prevent the use of that API in any pharmaceutical formulation that infringes the patent's claims until the patent expires.
Citations
[1] World Intellectual Property Organization. (2010, June 24). Patent application WO2010069955A1. Retrieved from https://patents.google.com/patent/WO2010069955A1/en
[2] IP Australia. (n.d.). Australian Patent Register Search. Retrieved from https://search.ipaustralia.gov.au/ (Specific record for AU2009329952 accessed for grant date and status).
[3] Spectrum Pharmaceuticals, Inc. (2023). Folotyn® (pralatrexate) Prescribing Information. (Note: While specific PI details are proprietary, the acquisition of Allos by Spectrum is public information).
[4] United States Securities and Exchange Commission. (2012, May 30). Spectrum Pharmaceuticals, Inc. - Form 8-K. Retrieved from https://www.sec.gov/ (Filing detailing the acquisition of Allos Therapeutics by Spectrum Pharmaceuticals).
