UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
 
FORM 8-K
 
CURRENT REPORT
 
Pursuant to Section 13 or 15(d)
of the Securities Exchange Act of 1934
 
April 19, 2016
Date of Report (Date of earliest event reported)
 
Flex Pharma, Inc.
(Exact name of registrant as specified in its charter)

 	 	 	 	 	
Delaware	 	001-36812	 	46-5087339	
(State or other jurisdiction	 	(Commission File Number)	 	(IRS Employer Identification No.)	
of incorporation)	 	 	 	 	

 	 	 	
800 Boylston Street, 24th Floor
Boston, MA	 	02199	
(Address of principal executive offices)	 	(Zip Code)	
 
Registrant’s telephone number, including area code: (617) 874-1821
 
Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligations of the registrant under any of the following provisions:
 
o                 Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
 
o                 Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
 
o                 Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
 
o                 Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 7.01 Regulation FD Disclosure.

On April 19, 2016, Flex Pharma, Inc. (the "Company") will present a poster and provide a presentation, each of which is entitled " Orally-administered TRPV1 and TRPA1 Activators Reduce Night Leg Cramps in a Randomized, Blinded, Placebo-Controlled, Crossover Human Trial, " at the Annual Meeting of the American Academy of Neurology. The poster and presentation are furnished herewith as Exhibits 99.1 and 99.2, respectively.

Forward-Looking Statements.

Statements contained in, or incorporated by reference into, this Current Report on Form 8-K regarding matters that are not historical facts are "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Risks are described more fully in the Company's filings with the Securities and Exchange Commission, including without limitation the Company's most recent Annual Report on Form 10-K and other documents subsequently filed with or furnished to the Securities and Exchange Commission. All forward-looking statements contained in this Current Report on Form 8-K speak only as of the date on which they were made. The Company undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made.

The information contained in this Item 7.01 and Exhibits 99.1 and 99.2 attached hereto shall not be deemed "filed" for purposes of Section 18 of the Securities and Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such filing.

Item 9.01.Financial Statements and Exhibits.
 
(d)                                 Exhibits

 	 	 	 	
Exhibit No.	 	Description	
99.1	
 	 	Flex Pharma, Inc. poster.	
99.2	
 	 	Flex Pharma, Inc. presentation.	

SIGNATURES
 
Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

 	 	 	
 	Flex Pharma, Inc.	
 	 	
Dated: April 19, 2016	 	
 	By:	/s/ Robert Hadfield	
 	 	Robert Hadfield	
 	 	General Counsel and Secretary	

INDEX TO EXHIBITS

 	 	 	 	
Exhibit No.	 	Description	
99.1	
 	 	Flex Pharma, Inc. poster.	
99.2	
 	 	Flex Pharma, Inc. presentation.	

Novel Treatments for Neuromuscular Condi4ons Orally-administered TRPV1 and TRPA1 Activators Reduce Night Leg Cramps in a Randomized, Blinded, Placebo-Controlled, Crossover Human Trial Cermak, J.M., Rosen, L.B., Hegarty, B.W., Bean, B.P., MacKinnon, R., Westphal, C.H., and Wessel, T. Flex Pharma, Inc. Boston, MA 02199 Nocturnal leg cramps (NLC) aﬀect millions of Americans, and there are no FDA- approved drug therapies. Recent experimental evidence argues that hyperexcitability of alpha-motor neurons is central to generaDng muscle cramps. IniDal observaDons in athletes led to the hypothesis that acDvaDon of TRPV1/ TRPA1 ion channels in mucous membranes of the oropharynx/upper GI tract increases inhibitory tone in the spinal cord, dampening motor neuron hyperexcitability. Recent evidence in electrically- and voliDonally-induced cramps in athletes supports this hypothesis. We invesDgated the safety and eﬃcacy of a proprietary formulaDon of TRP acDvators (TRP-SDm) in NLC in a randomized, blinded, placebo-controlled, crossover trial in subjects with cramps at least 4 nights/week. ATer an iniDal placebo run-in period, 51 evaluable subjects (50-77 years) were randomized to either placebo or TRP-SDm for two weeks, then crossed over for two weeks. StaDsDcally signiﬁcant eﬀects were demonstrated on key endpoints: cramp frequency (p<0.05); cramp-free days (p<0.01), the physician-rated Clinical Global Impression of Change (p<0.01); and speciﬁc sleep disturbance (p<0.05) and pain measures (p<0.01). The product appeared to be safe and well-tolerated, with no serious adverse events. The magnitude of cramp reducDon appears to be similar to published “Class 1 level” quinine eﬃcacy studies (quinine was banned by the FDA for leg cramps due to safety issues) (1). Finally, a subset of subjects had a pronounced clinical beneﬁt. These results demonstrate that TRP acDvaDon can reduce NLC. This supports the novel concept of Chemical Neuro SDmulaDon, a process whereby small molecules acDvate TRP ion channels topically, leading to sensory sDmulaDon that in turn reduces hyperexcitability in motor neurons at mulDple levels in the spinal cord. The human eﬃcacy signals generated in this study hold promise as a new approach in treaDng NLC and cramps in neurological disorders. Based upon these results, we plan to iniDate studies with a chemically-synthesized single molecule TRP acDvator in potenDal indicaDons such as NLC, MS and ALS. Summary Methods Summary & Conclusions 1.  Katzberg HD, Khan AH and So YT. Neurology. 74(8):691-6, 2010. 2.  Minetto MA, Holobar A, Botter A, and Farina D. Exerc. Sport Sci. Rev. 41(1): 3-10, 2013. 3.  Milanov, I. Electromyogr Clin Neurophysiol. 32 (2): 73-9, 1994. 4.  Okun, M. & Lampl, I. Nature Neurosci. 11: 535–537, 2008. 5.  Beilefeldt et al., Am J Physiol Gastrointest Liver Physiol 294: G130–G138, 2008. 6.  Yu et al., Am J Physiol Gastrointest Liver Physiol 297: G34–G42, 2009. References Nocturnal leg cramps (NLC) •  50% of those over the age of 50 suﬀer from NLC with increasing prevalence and frequency with age; Over 4 million in the US over age 65 suﬀer daily. •  Quinine, prescribed in the United Kingdom for NLC, is associated with thrombocytopenia, hypersensiDvity reacDons and QT prolongaDon and is no longer approved in the US for NLC, and no approved drug alternaDve exists in the US to treat NLC. Figure 2. Mul4-Center Trial in NLC: A randomized, double-blind, placebo- controlled, double cross-over study to evaluate the eﬀects of a Flex product on the frequency of nocturnal foot and/or leg cramps when self-administered approximately 45 minutes before going to bed. Background Figure 1. Overview of suspected mechanism of muscle cramps and methods of cramp inhibi4on by ac4va4on of TRP ion channels. Muscle cramping and spasDcity is thought to be caused by the uncontrolled and repeDDve ﬁring of α-motor neurons in the spinal cord (2, 3), resulDng in maintained contracDon of the muscle. Flex Pharma’s proprietary products exploit a general principle of neural circuits whereby strong excitatory sensory input from one source enhances overall inhibitory tone by increased recruitment of inhibitory neurons, thereby reducing excitability in other parts of the circuit (4). Flex Pharma’s products sDmulate primary sensory neurons in the mouth, esophagus and stomach by acDvaDng TRPV1 and TRPA1 ion channels (5,6). When acDvated, these sensory neurons, which project both directly and indirectly to the spinal cord, enhance the inhibitory tone in spinal cord circuits to reduce repeDDve ﬁring of α-motor neurons which prevents or reduces the frequency and intensity of muscle cramps and spasms. v  Nocturnal leg cramps aﬀect millions of Americans, but no approved drug therapy for NLC currently exists (quinine was banned by the FDA for leg cramps due to safety issues). v  Flex-100 inves4gated the safety and eﬃcacy of TRP ac4vators in a randomized, blinded, placebo-controlled, cross-over study in healthy subjects (50-77 years) suﬀering ≥ 4 night leg cramps/week. v  Treatment with TRP ac4vators resulted in sta4s4cally signiﬁcant eﬀects on clinically meaningful endpoints: cramp frequency (p<0.05); cramp-free days (p<0.01), physician- rated Clinical Global Impression of Change (p<0.01); “diﬃculty staying asleep” (p<0.05) and VAS pain intensity over the last 3 days of each treatment period (p<0.01). v  12% of subjects when treated with TRP ac4vators experienced a > 75% decrease in total cramps experienced over the two week treatment period. v  There were no serious adverse events; all adverse events reported were mild or moderate, transient and primarily gastrointes4nal: “4ngling lips” and “dyspepsia” were the most frequent. v  The magnitude of cramp reduc4on appears to be similar to published “Class 1 level” quinine eﬃcacy studies. v  Chemical Neuro S4mula4on of TRPV1 and TRPA1 channels in the oral mucosa may be a generally applicable method to treat disorders stemming from α-motor neuron hyperexcitability. v  Clinical studies will be ini4ated using the chemically-synthesized single molecule TRP ac4vator in poten4al indica4ons such as NLC, MS and ALS. Disposi4on and Demographics Disposi4on •  Overall, 64 subjects enrolled in Placebo Run-in •  13 subjects disconDnued aTer Placebo Run-in: •  9 for placebo response (CGI > 3 aTer placebo) •  ~ 15% placebo run-in exclusion rate •  1 for IVRS noncompliance, 1 for HbA1c out-of-range, 1 for no-show •  1 for con med carisoprodol (centrally acDng muscle relaxant) •  51 subjects were randomized to Periods 1 & 2 •  50 subjects complete •  1 subject disconDnued due to Adverse Event (AE) of UTI Demographics •  Of the N=51 randomized subjects: •  65 % were female; 35 % were male •  92% were White, 8 % were Black or African-American •  8% were Hispanic or LaDno; 92% were non-Hispanic or LaDno •  Mean age was 60.5 years (range 50-77) •  Mean BMI was 29 (range 21 – 46) Objec4ves & Endpoints Objec4ve: To assess the safety, tolerability, and exploratory eﬃcacy of TRP- sDmulator extracts vs. control beverage over a 2-weeks period on Nocturnal Legs Cramps (NLC) as assessed by the following endpoints: Eﬃcacy – Change from baseline in: 1)  Total number of cramps per period; 2)  Number of cramp-free days per period; 3)  Cramp pain/intensity assessments; 4)  Clinical Global Impression of Change; 5)  Quality of Life SF-36; and 6)  Insomnia Severity Index Safety: Safety endpoints will be the reported SAEs and unexpected AEs to the study treatment, vital signs, and laboratory assessments. Period 1 TRP-S4m 14 days Period 2 TRP-S4m 14 days Period 1 Placebo (beverage) 14 days Period 2 Placebo (beverage) 14 days ★ ★ ★ ★ ★ Study Visit Completers (N=50) ★ Recruitment and Screening (cramps for ≥ 3-4 nights per week for 4 consecu4ve weeks prior to Screening) Entered Period 1 (N=64) Exclude Placebo Responders à Randomized (N=51) Placebo Run-in (capsule) 14 days Baseline assessment at end of 2-week Run-in period Reported daily by subjects through an InteracDve Voice Response System (IVRS) Assessed by sites at the end-of-period study visits Results Results, cont. Red font = excluded aTer Placebo Run-in due to placebo response Responders = Much or Very Much Improved compared to Baseline •  40 % Responders on TRP-SDm Beverage •  24 % Responders on Placebo Beverage Period 1 Flex-Aid Placebo Scale (Score) N=62 N=50 N=49 ------------------------------------------------------------------------ Very Much Improved (1) 1 ( 2%) 7 ( 14%) 3 ( 6%) Much Improved (2) 6 ( 10%) 13 ( 26%) 9 ( 18%) Minimally Improved (3) 7 ( 11%) 16 ( 32%) 11 ( 22%) No Change (4) 34 ( 55%) 8 ( 16%) 18 ( 37%) Minimally Worse (5) 8 ( 13%) 1 ( 2%) 3 ( 6%) Much Worse (6) 1 ( 2%) 2 ( 4%) 0 ( 0%) Very Much Worse (7) 5 ( 8%) 3 ( 6%) 5 ( 10%) Figure 6. Clinical Global Impression of Change (CGI-C) by Treatment. Responders were deﬁned as those who scored 1 or 2 on the CGI-C, as assessed by the site principal invesDgators. TRP-SDm beverage treatment led to 40% of subjects being considered Responders vs. only 24% with Placebo beverage. Run-in TRP-S4m l Figure 4. Graphical representa4on of the mean daily cramp frequency for each cross-over period (Periods 1 and 2). The TRP-SDm treatment arms display nominal increasing eﬃcacy over the course of each crossover period, whereas the placebo arms show no improvement over the 14-day periods. Av er ag e n um be r o f c ra m ps 1 3 5 7 9 11 13 1 3 5 7 9 11 13 2.5 2.0 1.5 1.0 0.5 Day/Period 1 Day/Period 2 Placebo Placebo TRP-S5m TRP-S5m Poster No. 013 Figure 3. TRP-S4m treatment results in signiﬁcant diﬀerences rela4ve to placebo across mul4ple clinically meaningful endpoints. Figure 5. Percentage of par4cipants who experienced at least a 25%, 50%, or 75% decrease in the total number of cramps over the two week study period. Those individuals receiving TRP-SDm demonstrated a more pronounced cramp reducDon than Placebo in all groups, with only TRP-SDm showing a >75% reducDon. 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 25% 50% 75% % of P ar (c ip an ts % Decrease in Total Cramps per 2 Week Period TRP-S2m Placebo n=32 n=25 n=18 n=11 n=6 ≥ 25 % ≥ 50% ≥ 75% * p-values from Wilcoxon Signed Rank Test ** Responder analysis (answer of ‘none’ or ‘mild’) Green = staCsCcally signiﬁcant; amber = trend toward signiﬁcance Mean Median Change from Baseline in: TRP-SCm Placebo p-value TRP- SCm Placebo p-value* Total Cramps/ Period -7.0 -5.0 <0.05 -6 -4 <0.05 Total Cramp-Free Days/ Period 2.3 1.3 <0.01 2 1 <0.01 CGI 3.1 3.6 <0.01 3 4 <0.01 VAS Pain Intensity •  Mean / Period •  Mean / Last 3 Days of Period -6.7 -7.5 -3.6 -4.3 0.051 <0.01 Insomnia Severity Index (5 items): TRP- SCm Placebo p-value Sub-quesCon Q1b: •  Diﬃculty staying asleep** 39% 33% <0.05

 

Orally-administered TRPV1 and TRPA1 Activators Reduce Night Leg Cramps in a Randomized, Blinded, Placebo- Controlled, Crossover Human trial AAN Meeting, Vancouver, BC April 19, 2016 Jennifer Cermak, Laura B. Rosen, Brooke Hegarty, Bruce Bean, Rod MacKinnon, Christoph Westphal, and Thomas Wessel

 

Therapeutic Mechanism: Chemical Neuro Stimulation 0 25 50 75 100 125 0 50 100 150 200 Time (sec) EM G S ig na l ( uV ) Electrical stimulation to cause cramp Cramp, with Area Under the Curve (AUC) EM G S ig na l ( uV ) Subject no longer In cramp EM G ( be fo re s tim ul at io n) 0 25 50 75 100 125 0 50 100 150 200 Time (sec) EM G S ig na l ( uV ) Electrical stimulation to cause cramp EM G S ig na l ( uV ) Electrically Induced Cramp (EIC) Model

 

Flex-100 Nocturnal Leg Cramps Study Baseline Period 1 TRP Stim Beverage 14 days Period 2 TRP Stim Beverage 14 days Period 1 Placebo Beverage 14 days Period 2 Placebo Beverage 14 days ★ ★ ★ ★ Study Visits Completers N=50 ★ Recruitment and Screening (cramps for ≥ 3-4 nights per week for 4 consecutive weeks prior to Screening) Entered Run-In Period N=64 Exclude Placebo Responders Randomized N=51 Run-In Period (Placebo Capsule) 14 days Nocturnal leg cramps (NLC) •  50% >age 50 have NLC and >4 million in the US >65 years suffer daily •  Quinine (Rx for NLC in UK) is associated with thrombocytopenia, hypersensitivity reactions and QT prolongation and was banned by FDA for NLC in 1994 Flex multicenter US Trial in NLC: Randomized, double-blind, placebo-controlled, 2-period cross-over study to evaluate the effects of TRP stim on the frequency of NLC when taken ~ 45 minutes before going to bed

 

Flex-100 Results •  Treatment with TRP activators resulted in concordant clinically meaningful effects:   Cramp frequency (p<0.05)   Cramp-free days (p<0.01)   Physician-rated Clinical Global Impression of Change (p<0.01)   “Difficulty staying asleep” question on ISI (p<0.05)   VAS pain intensity over the last 3 days of each treatment period (p<0.05) •  Large proportion of patients had a positive and consistent beneficial response •  40% vs 24% “Very much improved” and “Much improved” on CGI-C •  No serious adverse events; generally well tolerated •  Magnitude of cramp reduction appears to be similar to published “Class 1 level” quinine efficacy studies (AAN evidence-based review, Katzberg et al, 2010) •  Chemical Neuro Stimulation of TRPV1 and TRPA1 channels in the oral mucosa may be a general method to treat disorders stemming from α-motor neuron hyperexcitability •  Clinical studies are being initiated using a potent single-molecule TRP activator for NLC and neurological indications ALS and MS