A patent infringement suit has been filed by Panacea Biotech Limited before the Delhi High Court for restraining Sanofi Healthcare India Pvt. Ltd. from marketing Hexavalent vaccine which will infringe Panacea’s patent for its fully liquid Whole-Cell Pertussis based fully liquid Hexavalent Vaccine, EasySix. The fight between Sanofi and Panacea has been since 2017 before the Indian Patent Office which has also been fought before the Bombay and Delhi High Court in 2018 and 2019. The drug EasySix developed by Panacea Biotech is used to vaccinate against Diphtheria, Tetanus, Whooping Cough, Hepatitis B, Haemophilus influenza type b, and Inactivated Polio (DTwP-HepB-Hib-IPV).

^{[Image Source:gettyimages]}

Panacea drug: this drug comes in a prefilled syringe and is the first of its kind Whole-Cell Pertussis-based fully liquid Hexavalent Vaccine. The EasySix has been marketed since 2017 and Panacea is planning to make this available to the government for vaccination/immunization domestically and internationally.

Sanofi received the market approval for the Whole-Cell Pertussis-based Hexavalent vaccine (DTwP-HepB-Hib-IPV) by the Drugs Controller General of India. "The suit filed against Sanofi comes at the heels of Sanofi having received marketing approval for a Whole-Cell Pertussis-based Hexavalent vaccine by the Drugs Controller General (India)," Panacea Biotec added. Recently when the matter was listed before the Delhi High Court, Sanofi undertook that it will not manufacture and market product that can infringe amended claims of Panacea patent, IN272351.

Pertussis

Pertussis (whooping cough) is caused by Bordetella pertussis, a small Gram-negative coccobacillus that infects the mucosal layers of the human respiratory tract. It is transmitted from infected to susceptible individuals through respiratory droplets. After an incubation phase of 7-10 days patients develop nose and throat inflammation and cough, and in the course of 1-2 weeks coughing spasms ending in the classical 'whoop' may occur. Bronchopneumonia, causing relatively high mortality, is the most prominent problem associated with pertussis.

Pertussis remains an important cause of infant death worldwide and continues to be a public health concern even in countries with high vaccination coverage. Maternal antibodies do not appear to protect neonates from severe pertussis, and even for individuals with vaccine-induced immunity, the initial antibody-mediated immune response to B. pertussis may minimize the toxic damage to both epithelial and immune cells, but it has limited impact on its subsequent circulation among non-immunized children and older individuals with waning immunity.

As per the Pertussis license is concerned, currently, two types of pertussis vaccine are licensed which are whole-cell pertussis (wP) and acellular pertussis (aP). Comparing both, Whole-Cell immunization has been comparatively effective and inexpensive.

Whole-cell pertussis vaccines were developed first and are suspensions of the entire B. pertussis organism that has been inactivated, usually with formalin. Most wP vaccines are available in combination with diphtheria (D) and tetanus (T) vaccines, which contain aluminum salts as an adjuvant and, thiomersal as a preservative. Immunization with wP vaccines is effective and the vaccine is relatively inexpensive, but immunization has been frequently associated with minor adverse reactions such as redness and swelling at the site of injection, along with fever and agitation. Local reactions tend to increase with age and the number of injections; wP vaccines are therefore not recommended for immunization of adolescents and adults.

To address the adverse reactions observed with the whole-cell vaccines, aP vaccines were developed that contain purified components of B. pertussis such as inactivated pertussis toxin either alone or in combination with other B. pertussis components such as filamentous haemagglutinin, fimbrial antigens, and pertactin. As with the whole-cell vaccines, a wide variation exists between the bacterial clones used, the number and quantity of components, the methods of purification and inactivation, and the formulation, making direct clinical comparisons between vaccines difficult. (Information taken from https://www.who.int/biologicals/vaccines/pertussis/en/)

For the primary series of immunization, aP vaccines have no greater frequency of adverse events than controls, although in subsequent doses a higher rate of swelling has been observed leading to the use of vaccines with reduced antigen content for adolescents and adults. In industrialized countries, the aP vaccine has gradually supplanted the use of the wP vaccine, nevertheless, the higher cost of development and production cost of aP vaccines made it more costly as compared to the dose of the wP vaccine. The efficacy of both the aP and wP vaccine remains almost the same, the wP vaccine remains the upper choice due to its less cost.

Sanofi will now be providing the argument towards the Panacea Biotech Claims and the suit will follow.

Author: Saransh Chaturvedi an associate at Global Patent Filing,  in case of any queries please contact/write back us at support@globalpatentfiling.com.